Ziada Ayorech

• Termorshuizen, Jet D.; Davies, Helena L.; Lee, Sang-Hyuck; Dennis, Jessica K.; Hübel, Christopher & Johnson, Jessica S. [Vis alle 186 forfattere av denne artikkelen] (2026). Genomic meta-analyses of binge-eating behavior and anorexia nervosa yield insights into the unique and shared biology of eating disorder phenotypes. Nature Mental Health. 4, s. 1361–1377. doi: 10.1038/s44220-026-00698-2. Fulltekst i vitenarkiv Vis sammendrag

  Eating disorders—including anorexia nervosa (AN), bulimia nervosa and binge-eating disorder—are clinically distinct but exhibit symptom overlap and diagnostic crossover. Genomic analyses have mostly examined AN. Here we conducted a genomic meta-analysis of case–control studies of binge-eating behavior (BE; 39,279 cases, 1,227,436 controls), alongside analyses of AN (24,223 cases, 1,243,971 controls) and its subtypes (all European ancestries). We identified six BE-associated loci, including loci associated with a higher body mass index and impulse-control behaviors. AN genome-wide association studies yielded eight loci, validating six loci. Subsequent polygenic risk score analysis demonstrated an association with AN in two East Asian ancestry studies. BE and AN exhibited similar positive genetic correlations with psychiatric disorders but opposing genetic correlations with anthropometric traits. Most of the genetic signal in BE and AN was not shared with body mass index. We have extended eating disorder genomics beyond AN; future work will incorporate multiple diagnoses and global ancestries.

• Bond, Tom A.; McAdams, Tom A.; Warrington, Nicole Maree; Hannigan, Laurie; Eilertsen, Espen Moen & Ayorech, Ziada [Vis alle 12 forfattere av denne artikkelen] (2026). Parental body mass index and offspring childhood body size and eating behaviour: A structural equation modelling analysis in the Norwegian Mother, Father and Child Cohort Study. PLoS Medicine. ISSN 1549-1277. 23(6). doi: 10.1371/journal.pmed.1005094. Fulltekst i vitenarkiv Vis sammendrag

  Background The intergenerational transmission of obesity-related traits could propagate an accelerating cycle of obesity, if parental adiposity causally influences offspring adiposity. The extent to which intergenerational obesity associations are due to such causal effects, as opposed to genetic confounding (inheritance), is unclear. We aimed to establish whether associations between parental peri-pregnancy body mass index (BMI) and offspring birth weight (BW), BMI until 8 years of age, and 8-year-old eating behaviour are due to genetic confounding. Methods and findings Data were from the Norwegian Mother, Father and Child Cohort Study, a prospective population-based birth cohort born between 1999 and 2009 at 50 out of 52 hospital maternity units in Norway. We compared the strength of the associations of maternal pre-pregnancy BMI versus paternal BMI during pregnancy, with offspring outcomes including birth weight and BMI assessed between age 6 months and 8 years of age, and appetite-related eating behaviour traits assessed at age 8 years via the Child Eating Behaviour Questionnaire (CEBQ), adjusting for potential confounders including parity, parental/grandparental language group and parental age, smoking, education and income). We then used an extended children of twins structural equation model (SEM) to quantify the extent to which associations were due to genetic confounding. Up to 85,866 children (51.3% male) were included in linear regression models, whereas SEM models included up to 50,999 children. Maternal BMI was more strongly associated than paternal BMI with offspring BW, but the maternal-paternal difference decreased for offspring BMI after birth. Greater parental BMI was associated with obesity-related offspring eating behaviours. SEM results indicated that genetic confounding did not explain the association between parental BMI and offspring BW, but explained the majority of the association with offspring BMI from 6 months onwards. For 8-year BMI, genetic confounding explained 79% (95% CI [62, 95]; p = 1.9 × 10−12) of the covariance with maternal BMI and 94% (95% CI [72, 113]; p = 2.7 × 10−14) of the covariance with paternal BMI. Limitations of this study include selective recruitment and attrition, potential bias due to parental assortative mating, and that findings may not generalise beyond high-income country settings with high obesity prevalence. Conclusions We found strong evidence that parent–child BMI associations may primarily be due to genetic confounding. When considered alongside prior evidence, this finding may argue against a strong causal effect of maternal or paternal adiposity on childhood adiposity via intrauterine or periconceptional mechanisms.

• Chegeni, Razieh; Nes, Ragnhild Bang; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Ystrøm, Eivind & Røysamb, Espen (2026). Direct and indirect parental genetic effects on offspring susceptibility to internalizing problems across development. Nature Mental Health. 4, s. 754–765. doi: 10.1038/s44220-026-00619-3. Fulltekst i vitenarkiv Vis sammendrag

  Internalizing problems, including symptoms of anxiety and depression, are common in childhood and adolescence and are linked to adverse long-term outcomes. Although both child genetic variants and parental genetic influences contribute to these problems, the specific direct (child) and indirect (parental) genetic pathways involved remain unclear. We applied multi-polygenic score models using elastic net regression to identify key genetic predictors of depressive and anxiety symptoms at ages 8 and 14 in 9,314 parent–child trios from the Norwegian Mother, Father and Child Cohort Study. We included 90 polygenic scores (PGSs) for the trio, along with their respective interaction terms. Predictive accuracy improved with age, with models explaining up to 2.7% of the variance in depression and 1.2% in anxiety. Key predictors included child attention deficit hyperactivity disorder, cognitive skills and well-being spectrum PGSs; maternal PGSs for smoking and cognitive skills; and paternal well-being spectrum PGSs. These findings underscore the value of incorporating diverse parental genetic traits to understand intergenerational risk transmission and developmental changes in child mental health.

• Valstad, Mathias; Eilertsen, Espen Moen; Ayorech, Ziada; Cheesman, Rosa Catherine Gillespie; Demange, Perline Aline Delle & Eftedal, Nikolai Haahjem [Vis alle 8 forfattere av denne artikkelen] (2026). Indirect genetic effects of siblings. Journal of Child Psychology and Psychiatry. ISSN 0021-9630. doi: 10.1111/jcpp.70130. Fulltekst i vitenarkiv Vis sammendrag

  Background Within-family designs are increasingly used to decompose genotype–trait associations into direct and indirect genetic effects. Many such designs, including trio designs or within-sibship designs, assume an absence of sibling indirect genetic effects. Methods We expand two well-known molecular genetic within-family designs, one variance component (genome-based restricted maximum likelihood) and one trait-based (structural equation modeling with polygenic indices), to estimate sibling indirect genetic effects, along with direct genetic effects. We link the Norwegian Mother, Father, and Child Cohort Study (MoBa) to Norway's national education database to model genetic effects on national standardized testing results at ages 10, 13, and 14, and on parent-rated attention-deficit hyperactivity disorder (ADHD) symptoms at ages 3 and 8 in up to 15,971 genotyped and phenotyped siblings. Results Estimates of direct and indirect genetic effects from the genome-based restricted maximum likelihood and the structural equation modeling with polygenic indices approaches converge, albeit with the variance component estimates typically an order of magnitude greater than the trait-based estimates. We observe no indirect genetic effects of siblings on educational performance at any age, and only slightly negative indirect genetic effects of siblings on ADHD symptoms at age 3. We argue that the latter effect might reflect parental contrasting ratings. Conclusions The results suggest that within-family models of educational performance are unlikely to be drastically biased by an assumption of absent sibling indirect genetic effects. Combining trait-based analyses with variance component analyses can benefit understanding of indirect genetic effects, especially when the effects are not specific to a particular mechanism.

• Eilertsen, Espen Moen; Eftedal, Nikolai Haahjem; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Ebeltoft, Joakim Coleman & Sunde, Hans Fredrik [Vis alle 9 forfattere av denne artikkelen] (2026). Multivariate maternal effects across the internalizing–externalizing spectrum in childhood: results from the Norwegian mother, father, and child cohort study. Journal of Child Psychology and Psychiatry. ISSN 0021-9630. s. 1–13. doi: 10.1111/jcpp.70111. Fulltekst i vitenarkiv Vis sammendrag

  Background From a functionalist perspective, parenting behaviors have adaptive functions and are partly expressions of genetic variation. Maternal genes that have effects on children are often referred to as indirect maternal genetic effects. Indirect genetic effects provide a means for measuring the role of parenting without the need for specifying the relevant parental behaviors. We studied indirect maternal genetic effects to address both the importance and commonality of parenting across the internalizing–externalizing spectrum of behavior problems in childhood. We further addressed how indirect genetic effects impact our understanding of direct genetic effects if not accounted for. Methods Utilizing data from the Norwegian Mother, Father, and Child Cohort Study (MoBa), our analyses involved 42,423 children and their mothers. Both pedigree and genotype data were used to infer genetic relationships. We applied multivariate latent variable models to distinguish indirect maternal genetic effects and direct offspring genetic effects on seven measures of internalizing–externalizing behaviors. Results Our findings indicate significant maternal genetic influences, explaining 7%–18% of the variance across internalizing–externalizing behaviors. A general maternal effect common across behaviors could adequately account for most of the variability. The analyses further indicate that direct child genetic effects appear smaller and more complex when indirect maternal genetic effects are modeled simultaneously. Conclusions By summarizing the effects of parenting with indirect maternal genetic effects, we show a substantial contribution of parents with respect to internalizing–externalizing behaviors in childhood. Although parenting is multifaceted, the effects of parenting are general and can succinctly be described as a single common dimension. Further, our study demonstrates that direct genetic effects appear smaller and more complex when maternal genetic effects are accounted for, highlighting the confounding potential of parental effects in understanding the role of genetic differences in child psychopathology.

• Ebeltoft, Joakim Coleman; Ystrøm, Eivind; Ayorech, Ziada & Eilertsen, Espen Moen (2026). Parental wealth and mental disorders in Norway (2006–2023): a nationwide registry-based study of 1.4 million young people. The Lancet Regional Health - Europe. 62. doi: 10.1016/j.lanepe.2025.101567. Fulltekst i vitenarkiv Vis sammendrag

  Background Young people from families with low socioeconomic position have higher rates of mental disorders. However, wealth is underexamined despite large wealth inequity worldwide. Here, we aim to investigate the relationship between early life parental wealth and mental disorders in young Norwegians. Methods We conducted a population study of associations between early-life parental wealth and 17 diagnostic categories of mental disorders in 1.4 M children (7–12), adolescents (13–18), and young adults (19–24) observed 2006–2023. Ranked parental socioeconomic indicators at age 0–6 (wealth, income, occupation, and education) and mental disorder diagnoses (ICD-10 and ICPC-2) were obtained from Norwegian Tax, Employment, Education, and Control and Payment of Health Reimbursements registries. Estimates were derived from mean prevalences, generalised estimating equations, and sibling comparison designs. Findings Parental wealth represents a gradient in young people’s mental disorders across age, sex, diagnostic categories, and cohorts. The lowest wealth quintile demonstrated 87% [95% CI = 78–96%] higher 1-year prevalence than the highest quintile. In multivariable analyses, parental wealth was the strongest predictor of mental disorders relative risk in adolescents (1.83 [1.76–1.9]) and young adults (1.92 [1.8–2.04]), while wealth (1.53 [1.46–1.6]) and education (1.52 [1.45–1.6]) were the strongest predictors in children. Parental wealth has a significant within-family association with mental disorders (relative risks: children 1.57 [1.44–1.71], adolescents 1.34 [1.26–1.42], young adults 1.42 [1.31–1.54]). Interpretation Our study serves as a point of reference for understanding the relationship between parental wealth and mental health. Our findings establish early life parental wealth as a fundamental social gradient in young people’s mental disorders.

• Chegeni, Razieh; Nes, Ragnhild Bang; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada Ng'ombo Laurel; Ystrøm, Eivind & Røysamb, Espen (2026). Parental direct and indirect genetic effects on offsprings’ internalizing problems across development. Nature Mental Health. doi: https:/www.researchsquare.com/article/rs-6862539/v1. Fulltekst i vitenarkiv Vis sammendrag

  Internalizing problems are common in youth and linked to adverse long-term outcomes. While both children’s own genetic variants (direct genetic effects) and the genetics of their parents (indirect genetic effects) contribute, the direct and indirect genetic traits involved remain unclear. Here, w...

• Braithwaite, Elizabeth C.; Haftorn, Kristine Løkås; Oftedal, Aurora; Ayorech, Ziada; Kaasen, Anne & Murgatroyd, Christopher [Vis alle 9 forfattere av denne artikkelen] (2025). Associations between lifetime history of depression, prenatal OXTR DNA methylation and breastfeeding outcomes. Clinical Epigenetics. 18(1), s. 1–12. doi: 10.1186/s13148-025-02030-8. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Background Women with depression are less likely to breastfeed and experience more breastfeeding challenges. Potential biological mechanisms that link maternal depression with poor breastfeeding outcomes have not been investigated. This study examined associations between lifetime history of depression (LHD), prenatal oxytocin receptor gene ( OXTR ) DNA methylation, and breastfeeding outcomes. Results Longitudinal observational data from the Norwegian Mother, Father and Child Cohort Study (MoBa) were analysed (N = 3607). LHD was self-reported during pregnancy (week 15). Blood samples were collected at 16–18 weeks of pregnancy, and DNA methylation was measured using the Illumina Methylation EPIC BeadChip 850 K array. This array includes 22 CpG sites on the OXTR gene, which were used in analyses. Mothers self-reported breastfeeding initiation (breastmilk given to child in first month), breastfeeding maintenance (breastmilk given to child for 6 months or more) and breastfeeding problems. Maternal LHD was not associated with OXTR DNA methylation. There was some evidence that prenatal OXTR DNA methylation was associated with breastfeeding outcomes. There was an association between CpG cg26455676 and breastfeeding maintenance to 6 months (odds ratio = 1.59, 95% confidence intervals = 1.11–2.27, raw p  = 0.01, adjusted p  = 0.04). Higher levels of DNA methylation at CpG cg26455676 was associated with a greater likelihood of maintaining breastfeeding to 6 months. Conclusions This highly novel study highlights the intriguing possibility that maternal prenatal DNA methylation at genes important for breastfeeding may be associated with breastfeeding experiences. Further understanding of vastly differing breastfeeding experiences would assist with the targeting efforts to support breastfeeding women, particularly those who are vulnerable, such as mothers who have depression.

• Hofgaard, Live Skow; Nes, Ragnhild Bang; Vassend, Olav Mandt; Ayorech, Ziada; Czajkowski, Nikolai Olavi & Røysamb, Espen (2025). Mental illbeing and wellbeing are influenced by recent adverse life events. Evidence from a longitudinal twin study. Current Psychology. ISSN 1046-1310. 44, s. 8723–8735. doi: 10.1007/s12144-025-07758-3. Fulltekst i vitenarkiv Vis sammendrag

  Adverse life events have been associated with increased mental illbeing and decreased wellbeing. These associations may partly reflect reverse causality and confounding genetics. Few studies have accounted for such effects, and few have compared the effect of adversities within and across different mental health outcomes. Our sample includes 1987 monozygotic and dizygotic twins born 1945-60, in the Norwegian Twin Registry, who responded to two questionnaires six years apart. We used biometric modelling to estimate genetic overlap and linear mixed models to control for previous levels of illbeing and wellbeing as well as genetic confounding in the associations between adverse life events and these outcomes. Our results indicate causal effects of cumulative adversity on increased illbeing and decreased wellbeing. Of the six adversities examined separately, financial strain and conflicts in romantic relationships showed the most profound effect on both outcomes. Conflicts with family/friends/neighbours and problems at work seem to primarily increase illbeing, while serious illness or injury mainly decrease wellbeing. This study supports previous findings that cumulative adversity represents a risk for increased illbeing and decreased wellbeing. Hence, exploring the number of recent adverse events could give valuable insight into individuals’ stressor load, and the reduction and prevention of such events should be important targets for preventive programs and policy. Importantly, our findings further suggest that the events that increase illbeing are not always overlapping with those that decrease wellbeing. This should be taken into consideration when assessing the needs of individuals after difficult experiences.

• Tamnes, Christian K.; Bekkhus, Mona; Eilertsen, Maja; Nes, Ragnhild Bang; Prydz, Monica Beer & Ystrom, Eivind [Vis alle 63 forfattere av denne artikkelen] (2025). The nature of the relation between mental well-being and ill-being. Nature Human Behaviour. 9(12), s. 2431–2440. doi: 10.1038/s41562-025-02319-x. Fulltekst i vitenarkiv
• Bjørndal, Ludvig Daae; Corfield, Elizabeth Claire; Hannigan, Laurie John; Ayorech, Ziada; Bulik, Cynthia M. & Watson, Hunna J. [Vis alle 12 forfattere av denne artikkelen] (2025). Prevalence, Characteristics, and Genetic Architecture of Avoidant/Restrictive Food Intake Phenotypes. JAMA pediatrics. ISSN 2168-6203. doi: 10.1001/jamapediatrics.2025.4786. Fulltekst i vitenarkiv Vis sammendrag

  Importance: A narrow range of food consumption and/or restricted eating is a core feature of avoidant/restrictive food intake (ARFI) disorder. However, there is limited knowledge of developmental characteristics of children with ARFI and its etiological influences, which constrains research, prevention, and intervention efforts. Objective: To estimate the prevalence of ARFI phenotypes in a population-based sample, examine developmental characteristics across childhood, and investigate the genetic architecture of ARFI using genome-wide association analyses. Design, Setting, and Participants: This preregistered study used data from children born from 1999 to 2009 in the population-based Norwegian Mother, Father, and Child Cohort Study (MoBa), with mother-reported data on ARFI symptoms at 3 and 8 years and linkage with diagnostic data from population health registries. Data were analyzed from March 2024 to May 2025. Exposures: Multiple items were used to identify children with broad ARFI. These children were subclassified into 3 groups based on symptom persistence: ARFI–broad transient (only at age 3 years), emergent (only at age 8 years), and persistent (ages 3 and 8 years). Children in these groups with 1 or more indicators of clinical significance (eg, nutritional deficiency) were further classified into ARFI-clinical subgroups. Main Outcomes and Measures: ARFI groups were compared across developmental characteristics from 6 months to 14 years. Genome-wide methods were used to examine single-nucleotide variant (SNV) heritability (SNV- h 2 ), conduct genetic association analyses, and quantify genetic correlations with other phenotypes. Results: Of 35 751 children with available ARFI assessments at 3 and 8 years (18 236 male [51%]), the prevalence of ARFI–broad persistent, transient, and emergent was 2129 (6.0%), 6338 (17.7%), and 3001 (8.4%), respectively. The prevalence of ARFI-clinical persistent, transient, and emergent was 624 (1.8%), 1157 (3.2%), and 484 (1.4%), respectively (2265 [6.3%] overall). Children with ARFI–broad persistent exhibited more developmental difficulties compared with children with no ARFI. SNV- h 2 ranged from 8% to 16%. Two independent genome-wide significant loci were identified. For ARFI-clinical, a significant association was identified with ADCY3 ( z  = 5.42; P  = 3.03 × 10 −8 ). Small to moderate genetic correlations were observed for ARFI-broad, ARFI-clinical and mental health, cognitive/educational, anthropometric, food-associated, and gastrointestinal disorder phenotypes. Conclusions and Relevance: This cohort study found that the prevalence of ARFI in the general pediatric population was substantial, and affected children had an associated elevated risk of developmental difficulties across multiple domains. Findings suggest a need for broad support interventions and advance understanding of the genetic underpinnings of ARFI.

• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2025). The genetic and environmental composition of socioeconomic status in Norway. Nature Communications. 16(1). doi: 10.1038/s41467-025-58961-6. Fulltekst i vitenarkiv Vis sammendrag

  Estimating the contributions of genetic and environmental factors is key to understanding differences in socioeconomic status (SES). However, the heritability of SES varies by measure, method, and context. Here, we estimate genetic and environmental sources of variance and commonality in the ‘big four’ SES indicators. We use high-quality administrative data on educational attainment, occupational prestige, income, and wealth, and employ four family-based and unrelated genotype-based heritability methods, all drawn from the same population-wide cohort of >170,000 Norwegians aged 35-45. By drawing subsamples from a consistent sample and using registry-based data, we reduce differences in estimates due to population characteristics and measurement error. Our results show that genetic variation consistently explains more for educational attainment and occupational prestige. Family-shared environmental contributions explained more for educational attainment and wealth. Our results highlight considerable common influences on the four SES indicators among genetic and shared environmental factors, but not among non-shared environmental factors. Overall, we show how the relative importance of genetic and environmental factors to SES differences in Norway varies by method and type of socioeconomic attainment. This study is a reliable source for comparing heritability methods, and for comparing SES indicators and their genetic and environmental commonality in a social-democratic welfare state.

• Cheesman, Rosa Catherine Gillespie; Anapaz, Ville; Alten, Sjoerd van; Abdellaoui, Abdel; Porneso, Ralph Pascual Ortiz & Ebeltoft, Joakim Coleman [Vis alle 16 forfattere av denne artikkelen] (2025). Genetic associations with educational fields. Nature Genetics. ISSN 1061-4036. 57, s. 2997–3006. doi: 10.1038/s41588-025-02391-z. Fulltekst i vitenarkiv Vis sammendrag

  Educational field choices shape careers, wellbeing and the societal skill distribution, yet genetic influences on what people study remain poorly understood. Here we show that genetic factors are associated with educational field specializations using genome-wide association studies (GWASs) across 463,134 individuals from Finland, Norway and the Netherlands (effective n between 40,072 and 317,209). We identified 17 independent genome-wide significant variants linked to 7 of 10 educational fields, with average heritability of 7%. The genetic signal is specific to field choice rather than educational level, persisting after controlling for years of schooling and confounding factors. By examining genetic clustering across specializations, we uncovered two key dimensions: technical versus social and practical versus abstract. We performed GWASs of these components and demonstrated distinct genetic correlations with personality, behavior and socioeconomic status. Our findings demonstrate that genomic research can illuminate ‘horizontal’ stratification, revealing insights into vocational interests and social sorting beyond traditional attainment measures.

• Bjørndal, Ludvig Daae; Eilertsen, Espen Moen; Ayorech, Ziada; Cheesman, Rosa; Ahmadzadeh, Yasmin I. & Baldwin, Jessie R. [Vis alle 13 forfattere av denne artikkelen] (2024). Disentangling direct and indirect genetic effects from partners and offspring on maternal depression using trio-GCTA. Nature Mental Health. 2(4), s. 417–425. doi: 10.1038/s44220-024-00207-3. Fulltekst i vitenarkiv Vis sammendrag

  Maternal depressive symptoms are highly prevalent and can negatively impact affected individuals and family members. Understanding etiological influences on maternal depression, such as genetic liability, is key to inform treatment and prevention efforts. Here we quantified direct and indirect genetic effects (that is, when genetic variants in other individuals influence risk of maternal depression through the environment) from partners and offspring on maternal depressive symptoms at multiple time points using genome-wide complex trait analysis with parent–offspring trios. We used data from the Norwegian Mother, Father and Child cohort study, including up to 21,000 genotyped parent–offspring trios. Models with indirect genetic effects had best fit at three out of five time points (3, 5 and 8 years after birth). The variance in maternal depressive symptoms explained by direct genetic effects ranged from 5% to 14%, whereas indirect genetic effects explained 0–14% of variance across time points. Heritable traits in family members contribute to maternal depressive symptoms through the environment at several time points after birth.

• Bjørndal, Ludvig Daae; Nes, Ragnhild Bang; Ayorech, Ziada; Vassend, Olav Mandt & Røysamb, Espen (2024). Multiple social factors are associated with wellbeing when accounting for shared genetic and environmental confounding. Quality of Life Research. ISSN 0962-9343. doi: 10.1007/s11136-024-03832-8. Fulltekst i vitenarkiv Vis sammendrag

  Purpose Social factors are associated with mental health and wellbeing. However, few studies have examined genetic and environmental influences on social factors themselves, limiting current understanding of influences on aspects of the social environment. Most studies which have identified links between social factors and mental health are also limited by the possible influence of unmeasured genetic and environmental confounding. In this study, we investigated the genetic and environmental underpinnings of multiple social factors (relationship satisfaction, loneliness, attachment, trust, relationship disruptions), and their associations with life satisfaction measured concurrently and six years later, after accounting for shared genetic and environmental confounding. Methods Data from a population-based sample of adult twins (N = 1987) and two measurement timepoints were used for the primary analyses. We used multivariate Cholesky models to estimate genetic and environmental influences across five social factors. Subsequently, we conducted co-twin control analyses to examine associations between social factors and wellbeing after controlling for shared genetic and environmental confounding. Results Heritability estimates for the social factors ranged from 24 to 42%. Genetic correlations across social factors were substantial, indicative of considerable genetic overlap. Associations between wellbeing and relationship satisfaction, loneliness, anxious and avoidant attachment, trust, and disruptions in relationships in the past year were attenuated in co-twin control analyses but remained statistically significant. Relationship satisfaction, loneliness, and attachment avoidance were also associated with wellbeing measured six years later in estimates which controlled for shared genetic and environmental confounding. Conclusion Our findings provide evidence that multiple social factors are associated with wellbeing after accounting for potential confounding by shared genetic and/or environmental factors. These findings highlight the importance of multiple aspects of the social environment for wellbeing in older adulthood. Future studies should examine the directionality in associations between social factors and mental health and assess these relationships beyond older adulthood.

• Simela, Carl; Akanbi-Akinlolu, Tolúwalàse; Okundi, Malaika; Abdalla, Hannah; McAdams, Tom A. & Harris, Androulla [Vis alle 11 forfattere av denne artikkelen] (2024). Intergenerational consequences of racism in the United Kingdom: a qualitative investigation into parents' exposure to racism and offspring mental health and well-being. Child and Adolescent Mental Health. ISSN 1475-357X. 29(2), s. 181–191. doi: 10.1111/camh.12695. Fulltekst i vitenarkiv
• Mayerhofer, Lilian Juliane Kozlowski; Nes, Ragnhild Bang; Yu, Baeksan; Ayorech, Ziada; Lan, Xiaoyu & Ystrøm, Eivind [Vis alle 7 forfattere av denne artikkelen] (2024). Stability and change in maternal wellbeing and illbeing from pregnancy to three years postpartum. Quality of Life Research. ISSN 0962-9343. 33, s. 2797–2808. doi: 10.1007/s11136-024-03730-z. Fulltekst i vitenarkiv Vis sammendrag

  Purpose Motherhood affects women’s mental health, encompassing aspects of both wellbeing and illbeing. This study investigated stability and change in wellbeing (i.e., relationship satisfaction and positive affect) and illbeing (i.e., depressive and anxiety symptoms) from pregnancy to three years postpartum. We further investigated the mutual and dynamic relations between these constructs over time and the role of genetic propensities in their time-invariant stability. Data and methods This four-wave longitudinal study included 83,124 women from the Norwegian Mother, Father, and Child Cohort Study (MoBa) linked to the Medical Birth Registry of Norway. Data were collected during pregnancy (30 weeks) and at 6, 18 and 36 months postpartum. Wellbeing and illbeing were based on the Relationship Satisfaction Scale, the Differential Emotions Scale and Hopkins Symptoms Checklist-8. Genetics were measured by the wellbeing spectrum polygenic index. Analyses were based on random intercept cross-lagged panel models using R. Results All four outcomes showed high stability and were mutually interconnected over time, with abundant cross-lagged predictions. The period of greatest instability was from pregnancy to 6 months postpartum, followed by increasing stability. Prenatal relationship satisfaction played a crucial role in maternal mental health postpartum. Women’s genetic propensity to wellbeing contributed to time-invariant stability of all four constructs. Conclusion Understanding the mutual relationship between different aspects of wellbeing and illbeing allows for identifying potential targets for health promotion interventions. Time-invariant stability was partially explained by genetics. Maternal wellbeing and illbeing develop in an interdependent way from pregnancy to 36 months postpartum.

• Ayorech, Ziada; Torvik, Fartein Ask; Cheesman, Rosa; Eilertsen, Espen M.; Valstad, Mathias & Bjørndal, Ludvig Daae [Vis alle 9 forfattere av denne artikkelen] (2024). The structure of psychiatric comorbidity without selection and assortative mating. Translational Psychiatry. 14(1), s. 1–9. doi: 10.1038/s41398-024-02768-4. Fulltekst i vitenarkiv
• Braithwaite, Elizabeth C.; Oftedal, Aurora; Kaasen, Anne; Ayorech, Ziada & Bekkhus, Mona (2024). A history of depression and prenatal depression are associated with a lower likelihood of breastfeeding initiation and maintenance, and more breastfeeding problems. Archives of Women's Mental Health. ISSN 1434-1816. 28, s. 139–146. doi: 10.1007/s00737-024-01479-5. Fulltekst i vitenarkiv Vis sammendrag

  Purpose This study tests the hypotheses that lifetime history of depression, and prenatal depression, are associated with a reduced likelihood of breastfeeding initiation (giving the baby any breastmilk during the first week of life) and breastfeeding maintenance (giving the baby breastmilk for at least 6 months), and a greater likelihood of reporting breastfeeding problems. Methods We analyzed data from the Norwegian Mother, Father, and Child cohort study (MoBa), N=78,307. Mothers reported a lifetime history of depression during the second trimester of pregnancy, and current symptoms of depression during the third trimester using the Hopkins Symptoms Checklist short version (SCL-8). At six months postpartum, mothers self-reported breastfeeding initiation, maintenance, and difficulties. Results Using binary logistic regression analyses, we report that a lifetime history of depression is associated with a lower likelihood of breastfeeding initiation (OR=0.751, 95%CI=0.650–0.938), breastfeeding maintenance (OR=0.712, 95%CI=0.669–0.785), and a greater likelihood of breastfeeding difficulties (OR=1.86, 95%CI=1.72–2.06). Similarly, prenatal depression was associated with a lower likelihood of breastfeeding initiation (OR=0.904, 95%CI=0.878–0.929), breastfeeding maintenance (OR=0.929, 95%CI=0.920–0.938), and a greater likelihood of breastfeeding difficulties (OR=1.10, 95%CI=1.09–1.12). Results remained largely unchanged when covaried for several confounding variables, including medication use. Conclusion We provide novel evidence that pre-conception and prenatal symptoms of depression are associated with breast-feeding outcomes. This information could be used to identify women very early in pregnancy who may need additional support with breastfeeding. There is also a need to fully understand the biopsychosocial mechanisms that mediate the relationship between depression prior to birth and breastfeeding outcomes.

• Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Eilertsen, Espen Moen & Ystrøm, Eivind (2023). Why we need families in genomic research on developmental psychopathology. JCPP Advances. 3(1). doi: 10.1002/jcv2.12138. Fulltekst i vitenarkiv Vis sammendrag

  Background Fundamental questions about the roles of genes, environments, and their interplay in developmental psychopathology have traditionally been the domain of twin and family studies. More recently, the rapidly growing availability of large genomic datasets, composed of unrelated individuals, has generated novel insights. However, there are major stumbling blocks. Only a small fraction of the total genetic influence on childhood psychopathology estimated from family data is captured with measured DNA. Moreover, genetic influence identified using DNA is often confounded with indirect genetic effects of relatives, population stratification and assortative mating. Methods The goal of this paper is to review how combining DNA-based genomic research with family-based quantitative genetics helps to address key issues in genomics and push knowledge further. Results We focus on three approaches to obtaining more accurate and novel genomic findings on the developmental aetiology of psychopathology: (a) using knowledge from twin and family studies, (b) triangulating with twin and family studies, and (c) integrating data and methods with twin and family studies. Conclusion We support the movement towards family-based genomic research, and show that developmental psychologists are particularly well-placed to contribute hypotheses, analysis tools, and data.

• Ayorech, Ziada; Baldwin, Jessie R.; Pingault, Jean-Baptiste; Rimfeld, Kaili & Plomin, Robert (2023). Gene-environment correlations and genetic confounding underlying the association between media use and mental health. Scientific Reports. 13(1). doi: 10.1038/s41598-022-25374-0. Fulltekst i vitenarkiv
• Raffington, Laurel; Tanksley, Peter T.; Vinnik, Liza; Sabhlok, Aditi; Patterson, Megan W. & Mallard, Travis [Vis alle 10 forfattere av denne artikkelen] (2023). Associations of DNA-Methylation Measures of Biological Aging With Social Disparities in Child and Adolescent Mental Health. Clinical Psychological Science. ISSN 2167-7026. doi: 10.1177/21677026231186802. Fulltekst i vitenarkiv
• Ayorech, Ziada; Cheesman, Rosa; Eilertsen, Espen M.; Bjørndal, Ludvig Daae; Røysamb, Espen & McAdams, Tom A. [Vis alle 8 forfattere av denne artikkelen] (2023). Maternal depression and the polygenic p factor: A family perspective on direct and indirect effects. Journal of Affective Disorders. ISSN 0165-0327. 332, s. 159–167. doi: 10.1016/j.jad.2023.03.043. Fulltekst i vitenarkiv Vis sammendrag

  Within-family studies typically assess indirect genetic effects of parents on children, however social support theory points to a critical role of partners and children on women's depression. To address this research gap and account for the high heterogeneity of depression, we calculated a general psychiatric factor using eleven major psychiatric polygenic scores (polygenic p), in up to 25,000 parent-offspring trios from the Norwegian Mother, Father and Child Cohort Study (MoBa). Multilevel modeling of trio polygenic p was used to distinguish direct and indirect genetic effects on mothers depression during pregnancy (gestational age 17 and 30 weeks), infancy (6 months, 18 months) and early childhood (3 years, 5 years, and 8 years). We found mothers polygenic p predicts their depression symptoms (b = 0.092; 95 % CI [0.087,0.098]), outperforming prediction using a single major depressive disorder polygenic score (b = 0.070, 95 % CI [0.066,0.075]). Jointly modeling trio polygenic p revealed indirect genetic effects of fathers (b = 0.022, 95 % CI [0.014,0.030]) and children (b = 0.021, 95 % CI [0.010,0.037]) on mothers' depression. Our results support the generalizability of polygenic effects across mental health and highlight the role of close family members on women's depression.

• Cheesman, Rosa Catherine Gillespie; Borgen, Nicolai T.; Lyngstad, Torkild Hovde; Eilertsen, Espen Moen; Ayorech, Ziada & Torvik, Fartein Ask [Vis alle 9 forfattere av denne artikkelen] (2022). A population-wide gene-environment interaction study on how genes, schools, and residential areas shape achievement. npj Science of learning. Fulltekst i vitenarkiv
• Cheesman, Rosa Catherine Gillespie; Borgen, Nicolai Topstad; Lyngstad, Torkild Hovde; Eilertsen, Espen Moen; Ayorech, Ziada & Torvik, Fartein Ask [Vis alle 9 forfattere av denne artikkelen] (2022). A population-wide gene-environment interaction study on how genes, schools, and residential areas shape achievement. npj Science of learning. 7, s. 1–9. doi: 10.1038/s41539-022-00145-8. Fulltekst i vitenarkiv Vis sammendrag

  Abstract A child’s environment is thought to be composed of different levels that interact with their individual genetic propensities. However, studies have not tested this theory comprehensively across multiple environmental levels. Here, we quantify the contributions of child, parent, school, neighbourhood, district, and municipality factors to achievement, and investigate interactions between polygenic indices for educational attainment (EA-PGI) and environmental levels. We link population-wide administrative data on children’s standardised test results, schools and residential identifiers to the Norwegian Mother, Father, and Child Cohort Study (MoBa), which includes >23,000 genotyped parent-child trios. We test for gene-environment interactions using multilevel models with interactions between EA-PGI and random effects for school and residential environments (thus remaining agnostic to specific features of environments). We use parent EA-PGI to control for gene-environment correlation. We found an interaction between students’ EA-PGI and schools suggesting compensation: higher-performing schools can raise overall achievement without leaving children with lower EA-PGI behind. Differences between schools matter more for students with lower EA-PGI, explaining 4 versus 2% of the variance in achievement for students 2 SD below versus 2 SD above the mean EA-PGI. Neighbourhood, district, and municipality variation contribute little to achievement (<2% of the variance collectively), and do not interact with children’s individual EA-PGI. Policy to reduce social inequality in achievement in Norway should focus on tackling unequal support across schools for children with difficulties.

Se alle arbeider i NVA

• Madhavan, Vaishnavi K; Demange, Perline Aline Delle; Ayorech, Ziada; Hottenga, Jouke Jan; Bartels, Meike & Ystrom, Eivind [Vis alle 8 forfattere av denne artikkelen] (2026). Bipolar Disorder and Education: Deciphering a Complex Relationship using Genetic and Sibling Differences. doi: https:/s3.amazonaws.com/ClubExpressClubFiles/971921/documents/BGA_2026_Final_Program_1883376854.pdf?AWSAccessKeyId=AKIA6MYUE6DNCQ7GISON&Expires=1790839847&response-content-disposition=inline%3B%20filename%3DBGA_2026_Final_Program.pdf&Signature=nfauyWIWzAanx8Du1HeYli1Hi0Q%3D. Fulltekst i vitenarkiv
• Ofstad, Sverre Berg; Peng, Qiyuan; Ebeltoft, Joakim; Bjørndal, Ludvig Daae; Rayner, Christopher & Ayorech, Ziada [Vis alle 10 forfattere av denne artikkelen] (2026). PGI-by-Environment interactions: practical guidelines for robust research. Fulltekst i vitenarkiv
• Ystrom, Eivind; Demange, Perline Aline Delle; Cheesman, Rosa Catherine Gillespie; McAdams, Thomas Andrew; Eilertsen, Espen Moen & Timpe, Clara Marie Fides [Vis alle 8 forfattere av denne artikkelen] (2026). Child Personality Polygenic Indices and Parental Distress: Evidence of Active Gene-Environment Correlations and Interactions from Parent–Offspring Trios. doi: https:/osf.io/fwaqp/overview. Fulltekst i vitenarkiv Vis sammendrag

  Child temperament and personality are conjectured to affect parental distress, and there are findings supporting such transactions. Yet, to date, there is no evidence for such evocative gene-environment correlations using exogenous within-family offspring genetic variation. Using 30 000 parent–offspring genotyped trios from the Norwegian Mother, Father and Child Cohort (MoBa), we test how child personality polygenic indexes (PGIs) independently affect maternal and paternal mental distress across the life course (age 16-60). The second longstanding hypothesis is that such child-to-parent transactions are non-additive due to gene-environment interactions. We will reveal the scope of this by estimating the expansion of within-person-timepoint parental mental distress over child personality PGIs. The third longstanding hypothesis is that the evocative effect is dependent on the parental personality, or the “goodness-of-fit”. We will examine moderation by parental Big Five PGIs to test if the effect of a child’s personality on parent depression depends on the parent’s own personality predispositions. This genetically controlled approach provides a novel and robust test of child- evoked effects across the life course. Results for both mothers and fathers will be presented, highlighting the power of child PGIs as a new tool to reveal intergenerational influences on parental mental distress.

• Ystrom, Eivind; Ayorech, Ziada; Bjørndal, Ludvig Daae; Timpe, Clara Marie Fides; Cheesman, Rosa Catherine Gillespie & Eilertsen, Espen Moen [Vis alle 8 forfattere av denne artikkelen] (2026). Child Personality Polygenic Indices and Parental Distress: Evidence of Active Gene- Environment Correlations and Interactions from Parent–Offspring Trios. doi: https:/bga.org/docs.ashx?id=1781704. Fulltekst i vitenarkiv
• Ofstad, Sverre Berg; Demange, Perline Aline Delle; Ayorech, Ziada; Valstad, Mathias & Ystrom, Eivind (2026). Temporal Trends in the Severity and Impairment of Childhood and Adolescent ADHD: A Population-Wide Genetic Study in Norway. Fulltekst i vitenarkiv Vis sammendrag

  By calculating family genetic risk scores for the entire for the entire Norwegian population for birth years 1992-2019, ages 6-16 (N ≈ 1.5M) we show that the reduction in functional impairment over time is largely attributed to a diagnostic expansion of less genetically severe cases. Those who are diagnosed today have lower levels of genetic risk, while simulatenously, there has been no change in the relationship between GPA at age 16 and genetic risk for ADHD.

• Bjørndal, Ludvig Daae; Valstad, Mathias; Eilertsen, Espen Moen; Ayorech, Ziada; Ofstad, Sverre Berg & Salvatore, Jessica E. [Vis alle 8 forfattere av denne artikkelen] (2026). Peer effects contribute to psychiatric disorder risk: A population-wide study. Fulltekst i vitenarkiv
• Ofstad, Sverre Berg; Demange, Perline Aline Delle; Ayorech, Ziada; Valstad, Mathias & Ystrom, Eivind (2026). Temporal Trends in the Severity and Impairment of Childhood and Adolescent ADHD: A Population-Wide Genetic Study in Norway. Fulltekst i vitenarkiv Vis sammendrag

  By calculating family genetic risk scores for the entire for the entire Norwegian population for birth years 1992-2019, ages 6-16 (N ≈ 1.5M) we show that the reduction in functional impairment over time is largely attributed to a diagnostic expansion of less genetically severe cases. Those who are diagnosed today have lower levels of genetic risk, while simulatenously, there has been no change in the relationship between GPA at age 16 and genetic risk for ADHD.

• Eilertsen, Espen Moen; Ayorech, Ziada Ng'ombo Laurel; Cheesman, Rosa Catherine Gillespie & Ystrøm, Eivind (2025). Et mangfold av ulikhet: Fra økonomi til gener. Fulltekst i vitenarkiv
• Ayorech, Ziada Ng'ombo Laurel & Ystrøm, Eivind (2025). Genes, Providers, and Depression: Expanding the Scope of Psychiatric Genetic Epidemiology to the Patient–Clinician Relationship. Fulltekst i vitenarkiv
• Ayorech, Ziada Ng'ombo Laurel & Ystrøm, Eivind (2025). Reflections of an early career researcher. Fulltekst i vitenarkiv
• Ayorech, Ziada Ng'ombo Laurel; Cheesman, Rosa Catherine Gillespie; Demange, Perline Aline Delle; Eilertsen, Espen Moen; Valstad, Mathias & Ystrøm, Eivind (2025). How the importance of family history and gender for receiving a depression diagnosis varies over GP’s. Fulltekst i vitenarkiv
• Ayorech, Ziada Ng'ombo Laurel (2025). Common misconceptions in Social Science Genetics. Fulltekst i vitenarkiv
• Ayorech, Ziada Ng'ombo Laurel (2025). Beyond the trio: Broadening the relationships we study to obtain new insights for improving mental health and wellness. Fulltekst i vitenarkiv
• Ayorech, Ziada Ng'ombo Laurel; Cheesman, Rosa Catherine Gillespie; Demange, Perline Aline Delle; Eilertsen, Espen Moen & Ystrøm, Eivind (2025). Leveraging family-based data reveals gene-environment interplay in life course depression. Fulltekst i vitenarkiv
• Rayner, Chris; Mcadams, Tom; Havdahl, Alexandra; Ystrøm, Eivind & Ayorech, Ziada Ng'ombo Laurel (2025). A repeated measures GWAS in relatives: detecting age-specific genetic effects on maternal depression. Fulltekst i vitenarkiv
• Ayorech, Ziada Ng'ombo Laurel & Ystrøm, Eivind (2025). Social Media as a Communication Tool. Fulltekst i vitenarkiv
• Izotova, Anastasia; Ayorech, Ziada; Fluit, Sam & Evje, Jacob (2025). Education of Mental Health Professionals in Norway and the Role of Intersectionality in Clinical Work - Panel discussion. Fulltekst i vitenarkiv
• Ayorech, Ziada (2025). GP Patient Relationship in Depression. Fulltekst i vitenarkiv
• Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada Ng'ombo Laurel & Ystrøm, Eivind (2024). Parent SES and young people's mental health. Fulltekst i vitenarkiv
• Cheesman, Rosa Catherine Gillespie; Eilertsen, Espen Moen; Ayorech, Ziada Ng'ombo Laurel; Ystrøm, Eivind; Hootegem, Arno Van & Lyngstad, Torkild Hovde (2024). Parent SES and offspring mental health. Fulltekst i vitenarkiv
• Ayorech, Ziada Ng'ombo Laurel; Cheesman, Rosa Catherine Gillespie; Demange, Perline Aline Delle; Eilertsen, Espen Moen; Valstad, Mathias & Ystrøm, Eivind (2024). GEOGRAPHICAL STRATIFICATION IN RECEIVING A DEPRESSION DIAGNOSIS IN THE NORWEGIAN POPULATION. doi: https:/www.sciencedirect.com/science/article/abs/pii/S0924977X24005455. Fulltekst i vitenarkiv Vis sammendrag

  Background Depression runs in families, has a striking female preponderance, and in 2030 is predicted to be the leading cause of disease burden worldwide. Receiving a depression diagnosis is critical for access to appropriate treatment to alleviate the debilitating symptoms associated with this common disorder. Evidence that patient characteristics can contribute to who receives a diagnosis is well documented, however the extent to which GP tendencies for diagnosing depression are geographically stratified is unknown, in part due to the sparsity of large scale diagnostic data in population cohorts. Methods Here we capitalize on registry data for ∼ 5 million Norwegian adults including all ICPC2 depression codes, GP, clinic and residential identifiers. Multilevel models are used to test whether the role of familial risk (i.e., affected siblings) in predicting diagnosis varies as a function of geographical location and GP characteristics. In addition we test whether GP diagnosing varies by patients genetic risk and self-report symptoms by adding depression polygenic scores and symptom checklist data for a subset of the population (200,000 genotyped participants in the Norwegian Mother Father and Child study (Moba)) to our models. Results We provide descriptions of depression clusters across the entire Norwegian country and critical insight into the path from symptoms to diagnosis. Crucially, this novel approach informs on whether provider leniency impacts the genetic signal captured in large scale genome-wide association studies of depression. Discussion These results will have implications for academics, clinicians and the more than 300 million individuals and their families suffering from depression worldwide.

• Qin, Qi; Ystrøm, Eivind; Eilertsen, Espen Moen; Ofstad, Sverre Berg; Ayorech, Ziada & Cheesman, Rosa Catherine Gillespie (2024). School-level Moderation of Multiple Within- Family Polygenic Index Effects on Educational Performance in MoBa (n=27476 Trios). Fulltekst i vitenarkiv
• Eilertsen, Espen Moen; Eftedal, Nikolai Haahjem; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Ebeltoft, Joakim Coleman & Sunde, Hans Fredrik [Vis alle 9 forfattere av denne artikkelen] (2024). Multivariate parental effects across the internalizing-externalizing spectrum in childhood: results from the Norwegian Mother, Father, and Child Cohort Study. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2024). Triangulating Approaches to Evaluate the Genetic and Environmental Composition of Socioeconomic Status. Fulltekst i vitenarkiv
• Ayorech, Ziada (2024). Leveraging family-based data reveals gene-environment interplay in life course depression. Fulltekst i vitenarkiv
• Ayorech, Ziada (2024). Family based methods for the 2023 Boulder Statistical Genetics Workshop. Fulltekst i vitenarkiv
• Ayorech, Ziada (2024). Family-based approaches to gene-environment interplay in life course depression. Fulltekst i vitenarkiv
• Ayorech, Ziada (2024). Family based approaches to life course depression. Fulltekst i vitenarkiv
• Ystrøm, Eivind; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada & Demange, Perline Aline Delle (2024). The dark matter of parenting – estimating the environmental importance of family members using genetics. Fulltekst i vitenarkiv
• Cheesman, Rosa Catherine Gillespie; Anapaz, Ville; Alten, Sjoerd van; Abdellaoui, Abdel; Ebeltoft, Joakim Coleman & Porneso, Ralph Pascual Ortiz [Vis alle 16 forfattere av denne artikkelen] (2024). The Genetics of Educational Fields. Fulltekst i vitenarkiv
• Nes, Ragnhild Bang; Ayorech, Ziada; Mayerhofer, Lilian; Moffitt, Terrie; Ystrøm, Eivind & Caspi, Avshalom [Vis alle 7 forfattere av denne artikkelen] (2024). Surrounded by Genes: The Interplay of Core Family Genetic Profiles on Mothers’ Wellbeing Across 14 Years. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2024). Parent SES and young people's mental health: Doctoral project. Fulltekst i vitenarkiv
• Qin, Qi; Ystrøm, Eivind; Eilertsen, Espen Moen; Ofstad, Sverre Berg; Ayorech, Ziada & Cheesman, Rosa Catherine Gillespie (2024). School-level Moderation of Multiple Within- Family Polygenic Index Effects on Educational Performance in MoBa (n=27476 Trios). Fulltekst i vitenarkiv
• Chegeni, Razieh; Nes, Ragnhild Bang; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Ystrøm, Eivind & Røysamb, Espen (2024). Surrounded by genes: Parental genetic effects on children’s mental health. Fulltekst i vitenarkiv
• Valstad, Mathias; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Demange, Perline Aline Delle & Eftedal, Nikolai Haahjem [Vis alle 8 forfattere av denne artikkelen] (2024). Indirect genetic effects of siblings. Fulltekst i vitenarkiv
• Chegeni, Razieh; Nes, Ragnhild Bang; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Ystrøm, Eivind & Røysamb, Espen (2024). Intergenerational transmission of internalizing behaviors: a multipolygenic score approach. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2024). Triangulating Approaches to Evaluate the Genetic and Environmental Composition of Socioeconomic Status: Multi-method study. Fulltekst i vitenarkiv
• Mayerhofer, Lilian Juliane Kozlowski; Nes, Ragnhild Bang; Yu, Baeksan; Ayorech, Ziada; Lan, Xiaoyu & Ystrøm, Eivind [Vis alle 7 forfattere av denne artikkelen] (2024). Journey of Love: Exploring Stability and Change in Relationship Satisfaction, Wellbeing, and Illbeing from Pregnancy to Three Years Postpartum. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2024). Genetic and environmental composition of SES. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2024). Doctoral project: Socioeconomic status and young people's mental health. Fulltekst i vitenarkiv
• Mayerhofer, Lilian Juliane Kozlowski; Nes, Ragnhild Bang; Yu, Baeksan; Ayorech, Ziada; Lan, Xiaoyu & Ystrøm, Eivind [Vis alle 7 forfattere av denne artikkelen] (2024). Journey of Love: Exploring Stability and Change in Relationship Satisfaction, Wellbeing, and Illbeing from Pregnancy to Three Years Postpartum. Fulltekst i vitenarkiv
• Mayerhofer, Lilian Juliane Kozlowski; Nes, Ragnhild Bang; Yu, Baeksan; Ayorech, Ziada; Lan, Xiaoyu & Ystrøm, Eivind [Vis alle 7 forfattere av denne artikkelen] (2023). From Romance to Motherhood: Transitions in Relationship Satisfaction, Wellbeing and Illbeing from Pregnancy to Toddlerhood. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Qin, Qi & Ystrøm, Eivind (2023). The inheritance of inequality: Comparing heritability estimates of socioeconomic status. Fulltekst i vitenarkiv
• Mayerhofer, Lilian Juliane Kozlowski; Nes, Ragnhild Bang; Ayorech, Ziada; Bartels, Meike; Ystrøm, Eivind & Røysamb, Espen (2023). Early manifestations of genetic profile in mental health phenotypes and the role of maternal wellbeing: findings from MoBa and NTR. Fulltekst i vitenarkiv
• Ayorech, Ziada (2023). Intergenerational approaches to Norwegian population data. Fulltekst i vitenarkiv
• Ayorech, Ziada; Cheesman, Rosa Catherine Gillespie; Eilertsen, Espen Moen; Havdahl, Alexandra & Ystrøm, Eivind (2023). Family-based approaches to gene-environment interplay. Fulltekst i vitenarkiv
• Cheesman, Rosa Catherine Gillespie; Ystrom, Eivind; Ayorech, Ziada; Eilertsen, Espen Moen; Ystrøm, Eivind & Ayorech, Ziada (2023). The Anatomy of Educational Fields. Fulltekst i vitenarkiv
• Cheesman, Rosa Catherine Gillespie; Ystrom, Eivind; Eilertsen, Espen Moen; Ayorech, Ziada & Ystrøm, Eivind (2023). The anatomy of educational fields. Fulltekst i vitenarkiv
• Ayorech, Ziada; Davies, Neil; Smith, George Davey; Watson, Hunna J; Yilmaz, Zeynep & Bulik, Cynthia M [Vis alle 15 forfattere av denne artikkelen] (2023). Causal risk factors for childhood eating behaviours and adulthood anorexia nervosa. A between and within family Mendelian randomisation study. Fulltekst i vitenarkiv
• Ayorech, Ziada; Cheesman, Rosa Catherine Gillespie; Eilertsen, Espen Moen; Havdahl, Alexandra & Ystrøm, Eivind (2023). The genetics of depression across the childbearing years. Fulltekst i vitenarkiv
• Haftorn, Kristine Løkås; Braithwaite, Elizabeth C; Page, Christian Magnus; Oftedal, Aurora; Ayorech, Ziada & Kaasen, Anne [Vis alle 8 forfattere av denne artikkelen] (2023). Does DNA methylation at the OXTR gene mediate associations between maternal lifetime history of depression and poor breastfeeding outcomes? Fulltekst i vitenarkiv
• Ayorech, Ziada; Torvik, Fartein Ask; Cheesman, Rosa Catherine Gillespie; Eilertsen, Espen Moen; Valstad, Mathias & Bjørndal, Ludvig Daae [Vis alle 9 forfattere av denne artikkelen] (2023). Leveraging family data can reveal the role of selection bias in genomic research. Fulltekst i vitenarkiv
• Qin, Qi; Cheesman, Rosa Catherine Gillespie; Eilertsen, Espen Moen; Ebeltoft, Joakim Coleman; Ayorech, Ziada & Ystrøm, Eivind (2023). School and geographical differences in the effect of heritable emotional and behavioral traits on educational performance. Fulltekst i vitenarkiv
• Qin, Qi; Cheesman, Rosa Catherine Gillespie; Eilertsen, Espen Moen; Ebeltoft, Joakim Coleman; Ayorech, Ziada & Ystrøm, Eivind (2023). School and geographical differences in the effect of heritable emotional and behavioural traits on educational performance. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Qin, Qi & Ystrøm, Eivind (2023). Inheritance of inequality: Comparing heritability estimates. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Qin, Qi & Ystrøm, Eivind (2023). Inheritance of inequality. Fulltekst i vitenarkiv
• Ayorech, Ziada; Baldwin, Jessie R.; Pingault, Jean-Baptiste; Rimfeld, Kaili & Plomin, Robert (2023). Author Correction: Gene-environment correlations and genetic confounding underlying the association between media use and mental health (Scientific Reports, (2023), 13, 1, (1030), 10.1038/s41598-022-25374-0). Scientific Reports. 13(1). doi: 10.1038/s41598-023-30112-1. Fulltekst i vitenarkiv
• mayerhofer, lilian; Ruiz, Virginia; Fluit, Sam & Ayorech, Ziada (2022). PSI Pride. Fulltekst i vitenarkiv
• Bjørndal, Ludvig Daae; Eilertsen, Espen Moen; Baldwin, Jessie R.; Ayorech, Ziada; Cheesman, Rosa Catherine Gillespie & Ahmadzadeh, Yasmin [Vis alle 13 forfattere av denne artikkelen] (2022). Disentangling intrafamilial effects on maternal depression using trio-GCTA. Fulltekst i vitenarkiv
• Ayorech, Ziada (2022). Why polygenic scores explain so little variance – yet we use them. Fulltekst i vitenarkiv
• Ayorech, Ziada (2022). Genetic and Geographic risk for Maternal Depression— the idea, results, and future directions. Fulltekst i vitenarkiv
• Ayorech, Ziada (2022). Intelligence. Fulltekst i vitenarkiv
• Ayorech, Ziada (2022). Diversifying Risk Prediction to Innovate Genetic and Environmental Models of Depression (DRIvE). Fulltekst i vitenarkiv
• Ayorech, Ziada; Ahmadzadeh, Yasmin & Wylde, Emily (2022). OwnTheMic -- A one day workshop for science communication. Fulltekst i vitenarkiv
• Ayorech, Ziada; Cheesman, Rosa Catherine Gillespie; Eilertsen, Espen Moen; Torvik, Fartein Ask; Andreassen, Ole & Havdahl, Alexandra Karoline Saasen [Vis alle 7 forfattere av denne artikkelen] (2022). The genetics of depression across the childbearing years. Fulltekst i vitenarkiv
• Hannigan, Laurie John & Ayorech, Ziada (2022). Polygenic scores: The good, the bad, and everything in between. Fulltekst i vitenarkiv
• Ahmadzadeh, Yasmin; Fayese, Tolúwalàse; Abdalla, Hannah; Okundi, Malaika; Simela, Carl & Ayorech, Ziada (2022). Experiences of Black researchers: engaging with anti-racism in research. Fulltekst i vitenarkiv
• Ayorech, Ziada (2022). Diversifying Risk Prediction to Innovate Genetic and Environmental Models of Depression (DRIvE). Fulltekst i vitenarkiv
• Ayorech, Ziada & Wootton, Robyn E (2022). Introduction to Mendelian Randomization. Fulltekst i vitenarkiv
• Ayorech, Ziada (2022). The potential of genetic methods for mental health research. Fulltekst i vitenarkiv
• Ayorech, Ziada (2022). Biology and Behaviour. Fulltekst i vitenarkiv
• Malanchini, Margherita & Ayorech, Ziada (2022). Visualizing data in Behavioural genetic research. Fulltekst i vitenarkiv
• Ayorech, Ziada & Smajlagic, Dinka (2022). Introduction to biology and genetics. Fulltekst i vitenarkiv
• Ahmadzadeh, Yasmin; Eilertsen, Espen Moen; Wechsler, Daniel; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada & Rayner, Cristopher [Vis alle 8 forfattere av denne artikkelen] (2022). Are mothers' prenatal emotional symptoms influenced by the foetal genome? Exploring the possibility of child-to-parent effects during pregnancy. Fulltekst i vitenarkiv
• Ebeltoft, Joakim; Ystrom, Eivind; Eilertsen, Espen Moen & Ayorech, Ziada (2026). Dissecting intergenerational patterns of socioeconomic status and mental disorders in Norway. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Socioeconomic status (SES) and mental disorders run in families—representing intergenerational persistence of advantages and disadvantages. Through three original research studies, this thesis investigates intergenerational patterns of socioeconomic status and mental disorders in Norway using genetically informed designs. First, in paper 1, I explore the coarse-grained etiology of the “big four” SES indicators —education, income, occupation, and wealth. By triangulating four advanced genetic methods, I demonstrate common and unique genetic and environmental sources of variance in parent SES. The substantial common variation across the “big four” is linked to genetic and shared environmental influences, while the considerable unique variance is explained by non-shared environment variation. Second, in paper 2, I assess the risk of mental disorders in young people given their parents’ SES—wealth in particular. In multivariable models including the “big four,” parental wealth is the strongest predictor of most mental disorder diagnoses in children, adolescents, and young adults. Significant associations between parent wealth and risk of mental disorders in young people persist after controlling for sibling-shared genetic and environmental factors. Third, in paper 3, I investigate the effects of children’s genetic differences on parents’ economic outcomes from 3 years before birth to 15 years after birth. By controlling for parent genetic factors, child genetic effects were identified using two methods. We found no conclusive evidence of child genetic effects on parent income, wealth, and government transfers. Three broad causal models can explain SES and mental disorder outcome correlations between parents (X) and their children (Y): A) third factors causing correlated observations (X←Z→Y), B) parent factors causing child outcomes (X→Y), and C) child factors causing parent outcomes (X←Y). Paper 1 provides evidence of model A, showing how common genetic and environmental factors explain large shares of the variance between the “big four” SES indicators. Paper 2 provides evidence of both model A and B, indicating that both shared genetic and environmental factors and parental wealth influence mental disorder risk in their children. Paper 3 provides inconclusive evidence of model C child genetic effects on their parents’ economic outcomes. This thesis argues that genetically informed designs are valuable for dissecting at least three important conceptual angles with regard to intergenerational patterns of SES and mental disorders: (i) genetic architecture as the focus—estimating the relative magnitude genetic contributions to phenotypes, and genetic correlations between phenotypes (paper 1); (ii) genetics as a confounder—estimating social effects while accounting for genetic similarity in families (papers 2 and 3), (iii) genetics as a proxy for a social effect—estimating socially-mediated genetic influences on another person’s phenotype (paper 3).

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