Trine Waaktaar

• Torgersen, Svenn Omar; Skaug, Eirunn & Waaktaar, Trine (2026). Common and Unique Etiological Influences on Personality and Personality Disorders in Youth. Psychopathology. ISSN 0254-4962. doi: 10.1159/psp/aelag006. Full text in Research Archive Show summary

  Background: Personality and personality disorders (PDs) are closely related constructs, but the nature of their relationship remains uncertain. Dimensional models suggest PDs are extreme manifestations of personality traits. We investigated the etiological links between broad personality factors and dimensional PD factors using quantitative analyses of common and unique genetic and environmental etiological factors affecting both normative and deviant personalities, emphasizing methods to minimize measurement bias. Methods: Seven national twin cohorts participated (N = 2,353 twins from 1,188 families), assessing personality traits with questionnaires across three adolescent waves and PD traits via age-19 clinical interviews. Exploratory factor analyses of personality traits and the three-cluster ABC factors of PDs simplified the factor structure of the measures. Biometric twin analyses with Cholesky modeling identified genetic and environmental links among factors. Results: Factor analysis of personality traits yielded non-resilient, disinhibited, and disaffected factors. PDs fit an emotional/erratic, anxious/fearful, and odd/eccentric factor structure. Phenotypic correlations varied, but the disinhibited factor had minimal relations to specific PD factors. Crucially, approximately one-third of the genetic variance was shared between personality and PDs. However, the majority of genetic variance and all non-shared environmental variance were trait-specific, suggesting predominantly distinct etiological pathways. Conclusion: The significant genetic overlap supports the continuum model; results were bolstered by using broad factors and method triangulation. However, unique genetic and environmental influences point to distinct etiological pathways differentiating personality and PDs. These findings endorse the continuum model yet highlight the need for further research to grasp the complex relationships between personality and PDs.

• Skaug, Eirunn; Waaktaar, Trine & Torgersen, Svenn (2026). The Influence of Personality Characteristics and Negative Life Events During Adolescence on Depression in Young Adulthood: A Longitudinal Twin Study. Twin Research and Human Genetics. ISSN 1832-4274. p. 12–12. doi: 10.1017/thg.2026.10090. Full text in Research Archive Show summary

  Abstract This study examined the influence of personality and negative life events during adolescence on depression in young adulthood, and the extent to which common genetic and environmental influences contributed to these associations. The data come from a Norwegian population based twin sample (N = 3,394). Depression was predicted by higher neuroticism and loneliness, as well as lower sense of coherence, self-efficacy, and resilience. Additionally, weak positive associations were found between negative life events and depression. Common genetic influences accounted for most of the phenotypic associations between depression and both personality and negative life events. The findings emphasize the importance of assessing personality characteristics early in adolescence, as they may serve as vulnerabilities for the development of depression later in life.

• Skaug, Eirunn; Waaktaar, Trine & Torgersen, Svenn Omar (2026). Stability and Change in Wellbeing Throughout Adolescence and Its Relationship with Life Events: A Longitudinal Twin Study. Behavior Genetics. ISSN 0001-8244. doi: 10.1007/s10519-026-10262-4. Full text in Research Archive
• Waaktaar, Trine; Skaug, Eirunn & Torgersen, Svenn Omar (2025). The etiological relationship between the general factors of psychopathology and personality; a longitudinal twin study from adolescence into young adulthood. Frontiers in Psychology. 16. doi: 10.3389/fpsyg.2025.1564305. Full text in Research Archive Show summary

  Background: Mental disorders and normal personality are interconnected domains. Recent studies highlight the dimensional and hierarchical nature of psychopathology and personality, focusing on their general factor levels. However, their relationship remains unclear. Aims: This study explored the etiological relationship between the general factors of psychopathology and personality from adolescence to young adulthood. Methods: Longitudinal data from seven national twin cohorts (N = 1,538 pairs) were collected across three waves (ages 12–22). Data was analyzed using a genetically informative random intercept cross-lagged panel model and Cholesky decomposition modeling. Results: Negligible cross-lagged effects were observed between the general factors. Both showed substantial stability, with genetic influences explaining most of the time-invariant variance. About one-quarter of genetic stability was shared. Conclusion: Psychopathology and personality are distinct yet parallel domains developing through adolescence into young adulthood. Notably, change in one did not lead to change in the other.

• Skaug, Eirunn; Waaktaar, Trine & Torgersen, Svenn Omar (2024). The relationship between personality throughout adolescence and social anxiety disorder in young adulthood. A longitudinal twin study. PLOS ONE. 19(3). doi: 10.1371/journal.pone.0299766. Full text in Research Archive Show summary

  This study examined the longitudinal relationship between a range of personality related variables measured throughout adolescence, and social anxiety disorder (SAD) in young adulthood. In addition, we examined to what degree the phenotypic associations between personality and SAD could be attributed to shared genetic and environmental factors, respectively. A total of 3394 twins (56% females), consisting of seven national birth cohorts from Norway, participated in the study. Personality was measured with self-report questionnaires at three times throughout adolescence, and SAD was measured with a diagnostic interview in early adulthood (M = 19.1 years, SD = 1.2). Correlation and regression analyses were performed to examine phenotypic associations between personality and SAD. We then created four composite scores of personality, in which the personality variables from four different ages throughout adolescence were weighted relative to their importance for SAD. Finally, a series of Cholesky decomposition models were used to examine the underlying genetic and environmental influences on the phenotypic associations between composite scores of personality and SAD. The results showed that especially higher neuroticism, lower extraversion, higher levels of loneliness, and lower levels of resilience, self-efficacy and sense of coherence, were associated with SAD. The phenotypic correlations between composite scores of personality and SAD increased from 0.42 when personality was measured 6–7 years prior to the assessment of SAD, to 0.52 when personality was measured shortly before the assessment of SAD. These phenotypic associations were mainly due to genetic influences, indicating that personality in adolescence predicts SAD in early adulthood due to shared genetic influences rather than having direct ‘causal’ effects on SAD.

• Skaug, Eirunn; Czajkowski, Nikolai Olavi; Waaktaar, Trine & Torgersen, Svenn Omar (2024). The Longitudinal Relationship Between Life Events and Loneliness in Adolescence: A Twin Study. Developmental Psychology. ISSN 0012-1649. 60(5), p. 966–977. doi: 10.1037/dev0001692. Full text in Research Archive Show summary

  The aim of the study was to examine associations between life events and self-assessed loneliness in adolescence. We used data from a Norwegian population-based twin sample including seven birth cohorts (N = 2,879, 56% females). The participants completed self-report questionnaires three times throughout adolescence, with 2 years in between (i.e., 12–18 years old at Wave 1). By using a random intercept cross-lagged panel model (RI-CLPM), we were able to separate stable influences in the measured constructs from the within-person changes at each measurement occasion. In addition, using data from twins allowed us to examine to what degree the associations between life events and loneliness were genetic and/or environmental in nature. The results showed moderate stability of both loneliness and aggregation scores of life events throughout adolescence. The life events were assigned to clusters based on their independence (i.e., events considered dependent or independent on a person’s behavior) and desirability (i.e., positive or negative). The time-stable between-person variance in all three measures, loneliness and person-dependent positive and negative life events, could almost exclusively be accounted for by genetic factors. However, as expected, also shared environmental factors influenced person-independent life events. The associations between time-stable between-person variance in loneliness and life events were small, and nearly exclusively due to shared genetic influences. Furthermore, life events do not seem to predict changes in loneliness or vice versa. In conclusion, the self-reported levels of loneliness throughout adolescence seems to be independent of life events.

• Lisøy, Carina; Neumer, Simon-Peter; Adolfsen, Frode; Ingul, Jo Magne; Rasmussen, Lene-Mari Potulski & Wentzel-Larsen, Tore [Show all 15 contributors for this article] (2024). Optimizing indicated cognitive behavioral therapy to prevent child anxiety and depression: A cluster-randomized factorial trial. Behaviour Research and Therapy. ISSN 0005-7967. 176. doi: 10.1016/j.brat.2024.104520. Full text in Research Archive Show summary

  Identifying effective components can lead to interventions that are less resource-intensive and better suited for real-world needs. In this 2×2×2 cluster-randomized factorial trial (clinicaltrials.gov NCT04263558), we investigated the effects of three components of an indicated, transdiagnostic CBT intervention for children: 1) Intervention Delivery Format (child group format versus a blended format with group sessions and automated web-based sessions), 2) Parental Involvement in the intervention (group-based versus psychoeducational brochure), and 3) a Measurement Feedback System (MFS; on versus off). The intervention was delivered at schools in a group-based format. The participants (N = 701 children) were school children (age 8–12 years) with elevated symptoms of anxiety or depression, and their parents. The main outcomes were self-reported (N = 633) and parent-reported (N = 725) symptoms of child anxiety and depression post-intervention. The secondary outcome was children's user satisfaction with the intervention. We did not find significant main or interaction effects of Delivery Format, Parental Involvement, or MFS on children's symptom levels. There were no significant effects on children's user satisfaction. Results were compatible with retaining the least resource intensive combination (i.e., blended format, parental brochure, no MFS) in an optimized intervention.

• Skaug, Eirunn; Czajkowski, Nikolai Olavi; Waaktaar, Trine & Torgersen, Svenn (2022). The role of sense of coherence and loneliness in borderline personality disorder traits: a longitudinal twin study. Borderline Personality Disorder and Emotion Dysregulation. 9. doi: 10.1186/s40479-022-00190-0. Full text in Research Archive Show summary

  Background Borderline personality disorder (BPD) implies having problems with identity and relations with other people. However, not much is known about whether these indications of BPD are present in adolescence, i.e., before personality disorders usually are diagnosed. In this study, we examined the prediction of an aspect of identity (i.e., sense of coherence [SOC]) and social relations (i.e., perceived loneliness) throughout adolescence on BPD traits in young adulthood. In addition, we examined to what degree the predictive ability could be attributed to genetic and environmental factors. We also examined whether life events in adolescence were related to BPD traits. Methods Three thousand three hundred ninety-one twins, consisting of seven national birth cohorts from Norway, participated in the study. SOC, loneliness and life events were measured three times throughout adolescence with self-report questionnaires, with 2 years in between measurements. BPD traits were measured at the end of adolescence around the age of 19 with a structured interview. Regression analyses were performed to examine the prediction of SOC, loneliness and life events on BPD traits. Cholesky decomposition models were then used to determine to what degree the associations were due to genetic and environmental influences. Results The prediction of SOC and loneliness on BPD traits increased from R = .25 (when measured 6 years prior to the assessment of BPD traits) to R = .45 (when measured shortly before the assessment of BPD traits). In addition, negative life events considered dependent on a person’s behavior were related to BPD traits. Negative independent and positive dependent life events did not contribute to the prediction of BPD traits. Cholesky decomposition models showed that SOC and loneliness were associated with BPD traits mainly due to shared genetic influences (i.e., the proportion due to genetic influences ranged from 71 to 86%). Adding negative dependent life events to the prediction of BPD traits did not change these percentages. Conclusions These findings indicate that the weaker SOC, the stronger feelings of loneliness, and the negative life events associated with BPD traits are mainly consequences of the genetic aspects of BPD traits, rather than having direct effects on levels of BPD symptoms.

• Skaug, Eirunn; Czajkowski, Nikolai Olavi; Waaktaar, Trine & Torgersen, Svenn (2022). Childhood Trauma and Borderline Personality Disorder Traits: A Discordant Twin Study. Journal of Psychopathology and Clinical Science. ISSN 2769-7541. 131(4), p. 365–374. doi: 10.1037/abn0000755. Full text in Research Archive
• Skaug, Eirunn; Czajkowski, Nikolai Olavi; Waaktaar, Trine & Torgersen, Svenn (2022). The relationship between life events and sense of coherence in adolescence. A longitudinal twin study. Journal of Research in Personality. ISSN 0092-6566. 99. doi: 10.1016/j.jrp.2022.104259. Full text in Research Archive Show summary

  This three-wave study examined the relationship between life events and sense of coherence (SOC) throughout adolescence by using genetically informative random intercept cross-lagged panel models. We also examined the genetic and environmental contribution to variance in the measured constructs. The data come from a Norwegian population-based twin sample (N = 2,878). Life events and SOC were associated, and both showed substantial genetic variance. Negative longitudinal effects were observed from negative dependent life events to SOC, from SOC to negative dependent life events and from SOC to positive dependent life events. However, these longitudinal effects were negligible in magnitude. In summary, the associations between all three clusters of life events and SOC were almost completely accounted for by shared genetic influences.

• Lisøy, Carina; Neumer, Simon-Peter; Waaktaar, Trine; Ingul, Jo Magne; Holen, Solveig & Martinsen, Kristin Dagmar (2022). Making high-quality measures available in diverse contexts — The psychometric properties of the Revised Child Anxiety and Depression Scale in a Norwegian sample. International Journal of Methods in Psychiatric Research. ISSN 1049-8931. 31(4), p. 1–13. doi: 10.1002/mpr.1935. Full text in Research Archive Show summary

  Objectives - Recent initiatives have recommended the Revised Child Anxiety and Depression Scale (RCADS) for use in research and as patient-reported outcome in health care globally. We aimed to investigate, for the first time, whether the psychometric properties of the anxiety and depression youth self-report measures, RCADS-47 and RCADS-25, generalize to a Norwegian setting.<p> <p>Methods - We examined gender and age differences in symptomatology among 592 children (mean age 10.7 years), and conducted a psychometric investigation of the internal reliability, structural validity, measurement invariance and convergent validity of the RCADS-47 and RCADS-25 youth versions.<p> <p>Results - Girls reported higher levels of anxious and depressive symptoms than boys, but no age differences were observed. Reliability coefficients for the RCADS-47 and RCADS-25 scales indicated good internal consistency. Structural validity for RCADS-47 and RCADS-25 was supported by confirmatory factor analyses results. For both measures, strong gender-based measurement invariance was present. Convergent validity of the RCADS-47 and RCADS-25 with other well-established self-report measures for anxiety (Multidimensional Anxiety Scale for Children) and depression (The Short Mood and Feelings Questionnaire) was supported.<p> <p>Conclusion - The RCADS-47 and RCADS-25 youth versions are valid and reliable instruments for measuring symptoms of anxiety and depression in a Norwegian setting. The results add to the evidence supporting RCADS's cross-cultural validity.

• Harstad, Stine; Bjåstad, Jon Fauskanger; Hjemdal, Odin; Compton, Scott; Waaktaar, Trine & Villabø, Marianne (2021). Competence and Adherence Scale for Cognitive Behavioural Therapy (CAS-CBT) for anxiety disorders in youth: Reliability and factor structure. Behavioural and Cognitive Psychotherapy. ISSN 1352-4658. 49(6), p. 745–757. doi: 10.1017/S1352465821000217. Full text in Research Archive
• Svensberg, K.; Kalleberg, Birgitte Grøstad; Rosvold, E.O.; Mathiesen, Liv; Wøien, H. & Hove, L.H. [Show all 11 contributors for this article] (2021). Interprofessional education on complex patients in nursing homes: a focus group study. BMC Medical Education. 21(1). doi: 10.1186/s12909-021-02867-6. Full text in Research Archive Show summary

  Background An ageing population leads up to increasing multi-morbidity and polypharmacy. This demands a comprehensive and interprofessional approach in meeting patients’ complex needs. This study describes graduate students’ experiences of working practice based in interprofessional teams with complex patients’ care needs in nursing homes. Method Students from advanced geriatric nursing, clinical nutrition, dentistry, medicine and pharmacy at the University of Oslo in Norway were assigned to groups to examine and develop a care plan for a nursing home patient during a course. Focus groups were used, 21 graduate students participating in four groups. Data were collected during spring 2018, were inductively analysed according to a thematic analysis method (Systematic Text Condensation). An analytical framework of co-ordination practices was applied to get an in-depth understanding of the data. Results Three themes were identified: 1) Complex patients as learning opportunities- an eye-opener for future interprofessional collaboration 2) A cobweb of relations, and 3) Structural facilitators for new collective knowledge. Graduate university students experienced interprofessional education (IPE) on complex patients in nursing homes as a comprehensive learning arena. Overall, different co-ordination practices for work organization among the students were identified. Conclusions IPE in nursing homes facilitated the students’ scope from a fragmented approach of the patients towards a relational and collaborative practice that can improve patient care and strengthen understanding of IPE. The study also demonstrated the need for preparatory teamwork training to gain maximum benefit from the experience. Something that can be organized by the education institutions in the form of a stepwise learning module and as an online pre-training course in interprofessional teamwork. Further, focusing on the need for well thought through processes of the activity by the institutions and the timing the practice component in students’ curricula. This could ensure that IPE is experienced more efficient by the students.

• Kandler, Christian; Waaktaar, Trine; Möttus, Rene; Riemann, Rainer & Torgersen, Svenn (2019). Unravelling the Interplay Between Genetic and Environmental Contributions in the Unfolding of Personality Differences from Early Adolescence to Young Adulthood. European Journal of Personality. ISSN 0890-2070. 33(3), p. 221–244. doi: 10.1002/per.2189. Full text in Research Archive Show summary

  In two studies, we examined the genetic and environmental sources of the unfolding of personality trait differences from childhood to emerging adulthood. Using self-reports from over 3000 representative German twin pairs of three birth cohorts, we could replicate previous findings on the primary role of genetic sources accounting for the unfolding of inter-individual differences in personality traits and stabilizing trait differences during adolescence. More specifically, the genetic variance increased between early (ages 10–12 years) and late (ages 16–18 years) adolescence and stabilized between late adolescence and young adulthood (ages 21–25 years). This trend could be confirmed in a second three-wave longitudinal study of adolescents’ personality self-reports and parent ratings from about 1400 Norwegian twin families (average ages between 15 and 20 years). Moreover, the longitudinal study provided evidence for increasing genetic differences being primarily due to accumulation of novel genetic influences instead of an amplification of initial genetic variation. This is in line with cumulative interaction effects between twins’ correlated genetic makeups and environmental circumstances shared by adolescent twins reared together. In other words, nature × nurture interactions rather than transactions can account for increases in genetic variance and thus personality variance during adolescence. © 2019 European Association of Personality Psychology

• Waszczuk, Monika Aldona; Waaktaar, Trine; Eley, Thalia C. & Torgersen, Svenn (2019). Etiological influences on continuity and co‐occurrence of eating disorders symptoms across adolescence and emerging adulthood. International Journal of Eating Disorders. ISSN 0276-3478. p. 1–10. doi: 10.1002/eat.23040. Full text in Research Archive Show summary

  Objective: The role of common and symptom‐specific genetic and environmental influences in maintaining eating disorder symptoms across development remains unclear. This study investigates the continuity and change of etiological influences on drive for thinness, bulimia, and body dissatisfaction symptoms and their co‐occurrence, across adolescence and emerging adulthood. Method: In total, 2,629 adolescent twins (mean age = 15.20, SD = 1.95) reported eating disorders symptoms across three waves of data collection. Biometric common pathways model was fitted to estimate genetic and environmental contributions to the continuity of each symptom over time, as well as time‐ and symptom‐specific influences. Results: Drive for thinness and body dissatisfaction symptoms showed a pattern of high continuity across development and high correlations with each other, whereas bulimia symptoms were moderately stable and less associated with the other two symptoms. Latent factors reflecting continuity of each symptom were largely under genetic influence (Al = 0.60–0.82). New genetic influences contributing to change in the developmental course of symptoms were observed in emerging adulthood. Genetic influences correlated considerably between the three symptoms. Non‐shared environmental influences were largely time‐and symptom‐specific, but some contributed moderately to the continuity across development (El = 0.18–0.40). The etiological overlap was larger between drive for thinness and body dissatisfaction symptoms than with bulimia symptoms. Discussion: The results provide preliminary evidence that stable as well as newly emerging genetic influences contribute to the co‐occurrence of drive for thinness, bulimia, and body dissatisfaction symptoms across adolescence and emerging adulthood. Conversely, environmental influences were less stable and contributed to change in symptoms over time.

• Martinsen, Kristin Dagmar; Rasmussen, Lene-Mari Potulski; Wentzel-Larsen, Tore; Holen, Solveig; Sund, Anne Mari & Løvaas, Mona Elisabeth S [Show all 10 contributors for this article] (2019). Prevention of anxiety and depression in school children: Effectiveness of the transdiagnostic EMOTION program. Journal of Consulting and Clinical Psychology. ISSN 0022-006X. 87(2), p. 212–219. doi: 10.1037/ccp0000360. Full text in Research Archive Show summary

  Objective: The objective of the study was to examine the effectiveness of a transdiagnostic program (EMOTION, Coping Kids Managing Anxiety and Depression) targeting symptoms of anxiety and depression in schoolchildren by comparing the intervention condition (EC) to a control condition (CC). Method: A clustered randomized design was used with schools as the unit of randomization. Children (N = 1686) aged 8–12 years in 36 schools completed screening using the Multidimensional Anxiety Scale (MASC-Child) and The Mood and Feelings Questionnaire Short version (SMFQ-Child). Scoring 1 SD above a population-based mean on anxiety and/or depression, 873 children were invited to participate. Intent-to-treat analyses were performed, and mixed-effects models were used. Results: Analyses revealed significant reductions of anxious and depressive symptoms as reported by the children, in which children in the intervention condition EC had almost twice the reduction in symptoms compared with the control condition CC. For parent report of the child’s depressive symptoms, there was a significant decrease of symptoms in the intervention condition EC compared with CC. However, parents did not report a significant decrease in anxious symptoms in the intervention condition EC as compared with CC. Conclusion: A transdiagnostic prevention program, provided in schools, was successful in reducing youth-reported symptoms of anxiety and depression and parent-reported depression. The EMOTION program has the potential to reduce the incidence of anxious and depressive disorders in youth.

• Torgersen, Svenn & Waaktaar, Trine (2019). The Oslo University Adolescent and Young Adult Twin Project: Recruitment and Attrition. Twin Research and Human Genetics. ISSN 1832-4274. p. 1–6. doi: 10.1017/thg.2019.51. Full text in Research Archive
• Waaktaar, Trine; Kan, Kees-Jan & Torgersen, Svenn (2018). The genetic and environmental architecture of substance use development from early adolescence into young adulthood: a longitudinal twin study of comorbidity of alcohol, tobacco and illicit drug use. Addiction. ISSN 0965-2140. 113(4), p. 740–748. doi: 10.1111/add.14076. Full text in Research Archive Show summary

  This is the peer reviewed version of the following article: Waaktaar, T., Kan, K.-J., and Torgersen, S. (2017) The genetic and environmental architecture of substance use development from early adolescence into young adulthood: a longitudinal twin study of comorbidity of alcohol, tobacco and illicit drug use. Addiction, which has been published in final form at http://dx.doi.org/10.1111/add.14076. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."

• Holen, Solveig; Waaktaar, Trine & Sagatun, Åse (2017). A Chance Lost in the Prevention of School Dropout? Teacher-Student Relationships Mediate the Effect of Mental Health Problems on Noncompletion of Upper-Secondary School. Scandinavian Journal of Educational Research. ISSN 0031-3831. 62(5), p. 737–753. doi: 10.1080/00313831.2017.1306801. Full text in Research Archive
• Martinsen, Kristin Dagmar; Holen, Solveig; Neumer, Simon-Peter; Waaktaar, Trine; Rasmussen, Lene-Mari Potulski & Kendall, Philip C [Show all 7 contributors for this article] (2017). The Factor Structure of MASC Youth Report in Norwegian School Children. Journal of Child and Family Studies. ISSN 1062-1024. 26(7), p. 1808–1816. doi: 10.1007/s10826-017-0705-9. Full text in Research Archive Show summary

  Identifying children with symptoms of anxiety before they develop clinical disorders is important. The objective of our study was to examine the latent factor structure of the MASC (youth report version) in a large self-selected sample of school children in 4th to 6th grade, and examine if the measure had a comparable factor structure for gender and age. Gender and age differences in anxiety symptoms were also examined. Children (N = 1686, 53.8% female) were recruited from schools during pretest of an ongoing randomized, controlled, indicative intervention. Latent variable modelling was used to determine the underlying concepts of the MASC. We found good model fit for the four-factor model, however some items on the Harm/Avoidance scale had low factor loadings. Invariance analysis indicated that the MASC had similar factor structure (comparable meaning) for boys and girls and for younger and older children in this sample. Girls scored significantly higher than boys on all subscales and on the Total Anxiety scale. Age differences were only found on the Separation Anxiety scale. Overall, the original four-factor structure of the MASC was confirmed within a large sample of school children and was invariant across gender and age. However, the Harm/avoidance scale warrants some attention. The MASC is a potentially useful measure to be used for screening purposes in a school setting.

• Ask, Helga; Waaktaar, Trine; Seglem, Karoline Brobakke & Torgersen, Svenn (2016). Common Etiological Sources of Anxiety, Depression, and Somatic Complaints in Adolescents: A Multiple Rater twin Study. Journal of Abnormal Child Psychology. ISSN 0091-0627. 44(1), p. 101–114. doi: 10.1007/s10802-015-9977-y. Full text in Research Archive
• Seglem, Karoline Brobakke; Waaktaar, Trine; Ask, Helga & Torgersen, Svenn (2016). Sex differences in genetic and environmental contributions to alcohol consumption from early adolescence to young adulthood. Addiction. ISSN 0965-2140. 111(7), p. 1188–1195. doi: 10.1111/add.13321. Full text in Research Archive
• Martinsen, Kristin Dagmar; Neumer, Simon-Peter; Holen, Solveig; Waaktaar, Trine; Sund, Anne Mari & Kendall, Philip C. (2016). Self-reported quality of life and self-esteem in sad and anxious school children. BMC Psychology. 4:45(1), p. 1–10. doi: 10.1186/s40359-016-0153-0. Full text in Research Archive Show summary

  Background: Anxiety and depressive symptoms are common in childhood, however problems in need of intervention may not be identified. Children at risk for developing more severe problems can be identified based on elevated symptom levels. Quality of life and self-esteem are important functional domains and may provide additional valuable information. Methods: Schoolchildren (n = 915), aged 9–13, who considered themselves to be more anxious or sad than their peers, completed self-reports of anxiety (Multidimensional Anxiety Scale for children (MASC-C), depression (The Short Mood and Feelings Questionnaire; SMFQ), quality of life (Kinder Lebensqualität Fragebogen; KINDL) and self-esteem (Beck self-concept inventory for youth (BSCI-Y) at baseline of a randomized controlled indicative study. Using multivariate analyses, we examined the relationships between internalizing symptoms, quality of life and self-esteem in three at-risk symptom groups. We also examined gender and age differences. Results: 52.1 % of the screened children scored above the defined at-risk level reporting elevated symptoms of either Anxiety and Depression (Combined group) (26.6 %), Depression only (15.4 %) or Anxiety only (10.2 %). One-way ANOVA analysis showed significant mean differences between the symptom groups on self-reported quality of life and self-esteem. Regression analysis predicting quality of life and self-esteem showed that in the Depression only group and the Combined group, symptom levels were significantly associated with lower self-reported scores on both functional domains. In the Combined group, older children reported lower quality of life and self-esteem than younger children. Internalizing symptoms explained more of the variance in quality of life than in self-esteem. Symptoms of depression explained more of the variance than anxious symptoms. Female gender was associated with higher levels of internalizing symptoms, but there was no gender difference in quality of life and self-esteem. Conclusion: Internalizing symptoms were associated with lower self-reported quality of life and self-esteem in children in the at-risk groups reporting depressive or depressive and anxious symptoms. A transdiagnostic approach targeting children with internalizing symptoms may be important as an early intervention to change a possible negative trajectory. Tailoring the strategies to the specific symptom pattern of the child will be important to improve self-esteem. Trial registration: Trial registration in Clinical trials: NCT02340637, June 12, 2014.

• Ulriksen, Robin; Sagatun, Åse; Zachrisson, Henrik Daae; Waaktaar, Trine & Lervåg, Arne (2015). Social Support and Socioeconomic Status Predict Secondary Students' Grades and Educational Plans Indifferently Across Immigrant Group and Gender. Scandinavian Journal of Educational Research. ISSN 0031-3831. 59(3), p. 357–376. doi: 10.1080/00313831.2014.965792. Full text in Research Archive
• Seglem, Karoline Brobakke; Torgersen, Svenn; Ask, Helga & Waaktaar, Trine (2015). Weak etiologic links between control and the externalizing behaviors delinquency and substance abuse in adolescence. Personality and Individual Differences. ISSN 0191-8869. 75, p. 179–184. doi: 10.1016/j.paid.2014.11.036. Full text in Research Archive Show summary

  Impulsive/disinhibitory personality traits have consistently been associated with externalizing symptomatology such as delinquency and substance use problems, often starting in adolescence. Yet the etiological nature of this co-occurrence is not well understood. Using a classic twin study design with self-report data from 717 male and female twin pairs, aged 15–18 years, a hierarchical psychometric model was examined. In this model the shared variance and etiological structure between control, delinquency and substance abuse symptoms, was modeled through a common externalizing factor. Model fitting indicated that the genetic and environmental influences differed in strength between male and female adolescents. The heritability of the externalizing factor was 45% in males and 10% in females, though neither was statistically different from zero. A statistically significant influence of shared environmental factors was seen for both sexes, 21% in males and 54% in females. In both sexes, the externalizing factor accounted for little variance in control, indicating a weak association and little shared etiology with externalizing liability. These results illuminate further that facets of impulsivity are differentially associated with vulnerability for externalizing symptomatology.

• Seglem, Karoline Brobakke; Waaktaar, Trine; Ask, Helga & Torgersen, Svenn (2015). Genetic and Environmental Influences on Adolescents’ Smoking Involvement: A Multi-informant Twin Study. Behavior Genetics. ISSN 0001-8244. 45(2), p. 171–180. doi: 10.1007/s10519-015-9706-x. Full text in Research Archive
• Ask, Helga; Torgersen, Svenn; Seglem, Karoline Brobakke & Waaktaar, Trine (2014). Genetic and environmental causes of variation in adolescent anxiety symptoms: A multiple-rater twin study. Journal of Anxiety Disorders. ISSN 0887-6185. 28(4), p. 363–371. doi: 10.1016/j.janxdis.2014.04.003. Full text in Research Archive Show summary

  Heritability estimates for adolescent anxiety vary across studies, partly depending on who is rating thesymptoms. The goal of our study was to estimate genetic and environmental influences using a multi-informant design with responses from a population-based sample of adolescent twins, their mothers andtheir fathers (N = 1394 families).Results from multivariate biometrical modeling indicated quantitative, but no qualitative sex differ-ences in etiology. The best fitting model was an AE Common Pathway model, defining anxiety as a latentfactor common to all informants. This model offers error free estimates of genetic and environmentalinfluences explaining the latent factor variance.Variation in the latent factor was highly genetic, with heritability estimates of 65% for boys and 74%for girls. Non-shared environmental effects explained the remaining variance. In addition, there weresignificant rater-specific genetic and environmental effects for both sexes.The observed rater differences underline the importance of using several informants when studyingadolescent anxiety.

• Holte, Arne; Barry, Margaret M.; Bekkhus, Mona; Borge, Anne Inger Helmen; Bowes, Lucy & Casas, Ferran [Show all 25 contributors for this article] (2014). Psychology of Child Well-Being. In Ben-Arieh, Asher; Casas, Ferran; Frønes, Ivar & Korbin, Jill E. (Ed.), Handbook of child well-being : theories, methods and policies in global perspective. Springer. ISSN 9789048190621. p. 555–631. doi: 10.1007/978-90-481-9063-8_13. Full text in Research Archive
• Waaktaar, Trine & Torgersen, Svenn (2013). Self-Efficacy Is Mainly Genetic, Not Learned: A Multiple-Rater Twin Study on the Causal Structure of General Self-Efficacy in Young People. Twin Research and Human Genetics. ISSN 1832-4274. 16(3), p. 651–660. doi: 10.1017/thg.2013.25. Full text in Research Archive Show summary

  Social learning theory postulates that self-efficacy is learned through the person's interaction with his/her physical and social environment. In this genetically informative, population-based, multi-informant study of 1,394 adolescent twin pairs, self-efficacy was modeled as one latent psychometric self-efficacy factor with genetic and environmental effects common to all informants, as well as for effects specific for each informant. The results showed that 75% of variation in self-efficacy was due to genetic factors. Non-shared environmental causes explained the remaining 25% of the variance in the latent factor, with no effect of common environment. Some informant-specific effects were also found. The present study challenges the theoretical assumption of learning as the dominant etiological factor behind self-efficacy in young people.

• Holen, Solveig; Waaktaar, Trine; Lervåg, Arne & Ystgaard, Mette (2013). Implementing a Universal Stress Management Program for Young School Children: Are there Classroom Climate or Academic Effects? Scandinavian Journal of Educational Research. ISSN 0031-3831. 57(4), p. 420–444. doi: 10.1080/00313831.2012.656320. Full text in Research Archive Show summary

  The purpose of this study was to investigate the possible academic and classroom climate effects of the universal school program Zippy's Friends, the primary objective of which is to strengthen children's ability to cope with stress. The sample consisted of 1483 children (aged 7–8 years) from 91 second-grade classes in 35 schools. The schools were matched and randomly assigned to intervention and control conditions. Classroom social climate and academic skills were assessed by the teachers and the children using an adapted version of the German scale SIKS (Social Integration, Classroom Climate and Self-concept of School Readiness). Using a multilevel approach, regression analysis of teacher reports indicated that the program had a positive effect on the social climate in the classroom, reduced bullying and improved academic skills. Analysis of children's reports found no significant overall effects. The results were not influenced by students' sex or socioeconomic status

• Schultz, Jon-Håkon; Sørensen, Peer Møller & Waaktaar, Trine (2012). Ready for School? Trauma Exposure and Mental Health in a Group of War-Affected Ugandan Adolescents Re-Attending School. Scandinavian Journal of Educational Research. ISSN 0031-3831. 56(5), p. 539–553. doi: 10.1080/00313831.2011.621132. Full text in Research Archive Show summary

  Abstract: The objective of this study was to assess trauma-related symptoms and mental health among war-exposed Ugandan adolescents (n = 81) as a basis for planning their re-attendance at school. Self-reports of exposure to traumatic events, trauma-related symptoms, and indicators of mental health were collected. While about half of the youths (51.9%) reported having been abducted by rebels and were former child soldiers, no differences were found in their mental health functioning compared to the remaining sample. Of the youths, 78% reported post-traumatic stress reactions of clinical significance. However, scores were within the normal range on conduct problems, hyperactivity, pro-social behavior, and self-efficacy. Even though the sample was clearly suffering from trauma-related symptoms, there were also marked areas of adaptive functioning and resilience. Whether the students are ready for education is discussed and implications for adapting educational programs for war-affected adolescents are indicated.

• Waaktaar, Trine & Torgersen, Svenn (2012). Genetic and Environmental Causes of Variation in Trait Resilience in Young People. Behavior Genetics. ISSN 0001-8244. 42(3), p. 366–377. doi: 10.1007/s10519-011-9519-5. Full text in Research Archive Show summary

  The aim of this multi-informant twin study was to determine the relative role of genetic and environmental factors in explaining variation in trait resilience in adolescents. Participants were consenting families (N = 2,638 twins in 1,394 families), from seven national cohorts (age 12-18 years, both sexes) of monozygotic and dizygotic twins reared together. Questionnaire data on the adolescents' Ego-resilience (ER89) was collected from mothers, fathers and twins, and analysed by means of multivariate genetic modelling. Variance in trait resilience was best represented in an ADE common pathways model with sex limitation. Variance in the latent psychometric resilience factor was largely explained by additive genetic factors (77% in boys, 70% in girls), with the remaining variance (23 and 30%) attributable to non-shared environmental factors. Additive genetic sources explained more than 50% of the informant specific variation in mothers and fathers scores. In twins, additive and non-additive genetic factors together explained 40% and non-shared environmental factor the remaining 60% of variation. In the mothers' scores, the additive genetic effect was larger for boys than for girls. The non-additive genetic factor found in the twins' self ratings was larger in boys than in girls. The remaining sex differences in the specific factors were small. Trait resilience is largely genetically determined. Estimates based on several informants rather than single informants approaches are recommended

• Waaktaar, Trine & Torgersen, Svenn (2012). Genetic and environmental causes of variation in perceived loneliness in young people. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics. ISSN 1552-4841. 159B(5), p. 580–588. doi: 10.1002/ajmg.b.32064. Full text in Research Archive Show summary

  Loneliness is prevalent in adolescence, despite the widespread expectation directed to young people to start building close relationships beyond the nuclear family. The aim of the present study was to explore the causal genetic and environmental structure behind variability in adolescents' perceived loneliness. Seven national cohorts (ages 12–18 years) of Norwegian twins reared together (1,394 twin pairs) participated. Perceived loneliness was measured with five items from the UCLA Loneliness Scale. Data were collected from mothers, fathers, and twins' self ratings by means of a posted questionnaire. Biometric analyses were applied, testing the causal architecture of loneliness within a psychometric model with one common latent factor in addition to specific genetic and environmental sources influencing the scores of each informant. The results showed a heritability (h2) of 75% on the latent perceived loneliness factor, and nonshared environmental effects (e2) explaining the remaining 25% of the latent factor variance. There were also significant rater-specific genetic and nonshared environmental effects. No shared environmental effects were found in the model, and there were no sex differences in the estimates. This study showed that variation in perceived loneliness in adolescents is highly genetic. Additional genetic and nonshared environmental etiological sources are to some extent represented in the scores of the specific rater.

• Holen, Solveig; Lervåg, Arne Ola; Waaktaar, Trine & Ystgaard, Mette (2012). Exploring the associations between coping patterns for everyday stressors and mental health in young schoolchildren. Journal of School Psychology. ISSN 0022-4405. 50(2), p. 167–193. doi: 10.1016/j.jsp.2011.10.006. Full text in Research Archive Show summary

  The purposes of this study were to explore the structure of coping with everyday stressors in a young nonclinical population and examine the relationship between coping and mental health. A total of 1324 children from 91 second-grade classes in 35 schools participated. Mental health was assessed using the parent and teacher forms of the Strengths and Difficulties Questionnaire (Goodman, 1997), and coping was assessed by the Kidcope (Spirito et al., 1988) self-report checklist. Exploratory and confirmatory factor analyses suggested a three-factor structure of coping. Latent-variable regression analysis indicated that coping categories including both active and emotional strategies were associated with fewer mental health problems, whereas withdrawal and oppositional coping strategies were associated with greater mental health problems. With some important exceptions, the results replicated previous studies of adults and adolescents. The need for new, more comprehensive coping assessments is highlighted.

• Holen, Solveig; Waaktaar, Trine; Lervåg, Arne & Ystgaard, Mette (2012). The effectiveness of a universal school-based programme on coping and mental health: a randomised, controlled study of Zippy's Friends. Educational Psychology. ISSN 0144-3410. 32(5), p. 657–677. doi: 10.1080/01443410.2012.686152. Full text in Research Archive Show summary

  The purpose of this study was to evaluate Zippy’s Friends, a universal school programme that aims at strengthening children’s coping skills. The sample consisted of 1483 children (aged 7–8 years) from 91 second-grade classes in 35 schools. The schools were matched and randomly assigned to intervention or control conditions. Coping was assessed by the Kidcope checklist for children and an adapted version for parents. Parents and teachers reported mental health outcomes using the Strengths and Difficulties Questionnaire. Controlling for the hierarchical structure of the data, latent variable regression analysis indicated that the programme had a significant positive effect on coping and on the impact of mental health difficulties in daily life. Subgroup analyses suggested that coping was improved in girls and children from the low socio-economic subgroup, whereas the impact of mental health difficulties was reduced in boys

• Waaktaar, Trine (2012). Resiliensforskning : Hvordan kan kunnskap fra dette feltet bidra til utviklingsfremmende arbeid i skolehelsetjenesten og med skolen som arena. In Olaisen, Kristin (Eds.), Utviklingsfremmende samtaler med ungdom : samhandling på tvers. Kommuneforlaget AS. ISSN 9788244621434. p. 276–283. Full text in Research Archive
• Jakobsen, Ida Skytte; Christiansen, Erik; Larsen, Kim Juul & Waaktaar, Trine (2011). Differences between youth with a single suicide attempt and repeaters regarding their and their parents history of psychiatric illness. Archives of Suicide Research. ISSN 1381-1118. 15(3), p. 265–276. doi: 10.1080/13811118.2011.589731. Full text in Research Archive
• Waaktaar, Trine & Torgersen, Svenn (2010). How resilient are resilience scales? The Big Five scales outperform resilience scales in predicting adjustment in adolescents. Scandinavian Journal of Psychology. ISSN 0036-5564. 51(2), p. 157–163. doi: 10.1111/j.1467-9450.2009.00757.x. Full text in Research Archive
• Waaktaar, Trine; Avdem, Jorid & Torgersen, Svenn (2006). Forebygging av vansker hos ungdom - hva kan vi lære av resiliensforskning? In Kleven, Karin; Talseth, Randi; Notøy, Ingunn & Vea, Ingeborg (Ed.), Barn i Norge 2006. Barn i risiko. Voksne for barn. ISSN 9788292488089. p. 27–34. Full text in Research Archive
• Waaktaar, Trine; Borge, Anne Inger Helmen; Christie, Helen & Torgersen, Svenn (2005). Youth-parent consistencies on ratings of difficulties and prosocial behaviour: Exploration of an at-risk sample. Scandinavian Journal of Psychology. ISSN 0036-5564. 46(2), p. 179–188. doi: 10.1111/j.1467-9450.2005.00447.x. Full text in Research Archive Show summary

  Low informant agreement is of particular concern in clinical settings, since diagnoses and interventions are largely based on reports from parents and/or youths. This study explores youth-parent consistencies in an at-risk sample of youths (n= 42), several from immigrant and refugee families, all with stressful background experiences. Data from a community sample (n= 165) was used to contrast the clinical results. Results showed that correlations between clinical youths and parents were within the same range as those in the community sample. Consistencies concerning absolute level of behavior were higher in the clinical sample. However, interesting differences in informant consistencies were found on difficulties and resources between the two samples. This study adds to the picture that there is no simple relationship between severity of behavior deviance and informant agreement. Asking about behavioral resources as well as difficulties may provide valuable additional information regarding differences in the perspectives of at-risk youths and parents.

• Waaktaar, Trine; Borge, Anne Inger Helmen; Fundingsrud, Hans Petter; Christie, Helen & Torgersen, Svenn (2004). The role of stressful life events in the development of depressive symptoms in adolescence. Journal of Adolescence. ISSN 0140-1971. 27(2), p. 153–163. Full text in Research Archive
• Waaktaar, Trine; Christie, Helen; Borge, Anne Inger Helmen & Torgersen, Svenn (2004). How can young people's resilience be enhanced? Experience from a clinical intervention project. Clinical Child Psychology and Psychiatry. ISSN 1359-1045. 9(2), p. 167–183. doi: 10.1177/1359104504041917. Full text in Research Archive
• Waaktaar, Trine; Christie, Helen; Borge, Anne Inger Helmen & Torgersen, Svenn (2004). Building youths' resilience within a psychiatric outpatient setting: Results from a pilot clinical intervention project. Psychological Reports. ISSN 0033-2941. 94(1), p. 363–370. doi: 10.2466/pr0.94.1.363-370. Full text in Research Archive
• Waaktaar, Trine; Christie, HJ; Borge, Anne Inger Helmen & Torgersen, Svenn (2004). Building youths&apos; resilience within a psychiatric outpatient setting: Results from a pilot clinical intervention project. Psychological Reports. ISSN 0033-2941. 94, p. 363–370. Full text in Research Archive
• Christie, Helen Johnsen & Waaktaar, Trine (1997). Tross alt: krigstraumatiserte barn og deres helingspotensialer. In Sveaass, Nora & Hauff, Edvard (Ed.), Flukt og fremtid: psykososialt arbeid og terapi med flyktninger. Gyldendal Akademisk. ISSN 9788241708329. p. 119–133. Full text in Research Archive Show summary

  Boken presenterer ulike perspektiv på forståelse av flyktningers livssituasjon og psykiske problemer. Vi føres inn i psykologiske, medisinske og sosialantropologiske tilnærminger til flyktningefeltet. I den andre delen legges det vekt på forebyggendearbeid, behandling av voksne og barn og samarbeid med tolk. Den siste delen beskriver utviklingen og organiseringen av psykososiale tjenester i Norge. Boken er skrevet for helsepersonell og andre som arbeider med flyktninger. Levert av © FS Informasjonstjenester

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• Waaktaar, Trine & Christie, Helen Johnsen (2000). Styrk sterke sider: håndbok i resiliencegrupper for barn med psykososiale belastninger. Kommuneforlaget AS. ISBN 9788244607711. 188 p. Full text in Research Archive Show summary

  Resilience handler om barnets evne til å klare seg på tross av at det har gjennomlevd sterke belastninger som krig, katastrofer og vanskelige oppveksvilkår. Resilienceforskning viser at de faktorene som kjennetegner barn som klarer seg, blant annet er at de finner noen områder der de kan erfare MESTRING, de har utviklet ulike kreative måter å uttrykke seg på, de henter styrke gjennom FELLESSKAP med jevnaldrene, og ikke minst er de kommet fram til en forståelse av belastningene de har vært gjennom, slik at livet igjen kan oppleves som KONTINUERLIG og meningsfylt. Resiliencegrupper er betegnelsen på den type tiltak som ble utviklet gjennom Resilienceprosjektet ved Nic Waals Institutt 1996 - 1999. Erfaringene fra prosjektet tilsier at tiltaket kan drives med utgangspunkt både i skole, skolehelsetjeneste, ungdomsklubber og fra mer etablerte terapeutiske miljøer som pedagogisk/psykologisk rådgivningstjeneste og barne- og ungdomspsykiatri. Jo mer traumatiserte og belastede deltakerene i en gruppe er, jo viktigere er det imidlertid at fagpersoner med terapeutisk kompetanse er involvert i tiltaket, som veileder og/eller som gruppeledere. Denne håndboken er en veileder i hvordan man kan drive resiliencegrupper. Den inneholder derfor en omfattende gjennomgang av hvordan en resiliencegruppe kan planlegges og gjennomføres.Veiledning betraktes som et vesentlig element i denne typen tiltak, og dette er derfor behandlet i et eget kapittel. Som bakgrunn for intervensjonen gis det en oversikt over resilienceforskning, det vises til teori som kan peke på hvilke prosesser som ligger bak resiliencefaktorene, og traume-/patologiperspektivet drøftes opp mot resilience/salutogenese. Det blir gitt referanser til anbefalt litteratur i tilknytning til hvert av de temaene som behandles i håndboken.

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• Lisøy, Carina; Askeland, Anne Liv; Martinsen, Kristin; Bania, Elisabeth Valmyr; Wentzel-Larsen, Tore & Adolfsen, Frode [Show all 15 contributors for this article] (2024). Less Is More? Viktige faktorer i et indikert gruppetiltak for barn med internaliserende vansker. Full text in Research Archive
• Martinsen, Kristin Dagmar; Neumer, Simon-Peter; Holen, Solveig; Waaktaar, Trine; Sund, Anne Mari & Løvaas, Mona Elisabeth S [Show all 11 contributors for this article] (2018). Effectiveness evaluation of the EMOTION program. Full text in Research Archive
• Martinsen, Kristin Dagmar; Neumer, Simon-Peter; Holen, Solveig; Waaktaar, Trine; Sund, Anne Mari & Patras, Joshua [Show all 8 contributors for this article] (2017). Indicated prevention of anxiety and depression in school children: Preliminary results from a randomized controlled trial of a new transdiagnostic intervention. Full text in Research Archive
• Martinsen, Kristin Dagmar; Neumer, Simon-Peter; Holen, Solveig; Waaktaar, Trine; Sund, Anne Mari & Patras, Joshua [Show all 8 contributors for this article] (2016). The EMOTION program - A transdiagnostic intervention targeting high levels of anxiety and depressive symptoms in children. Full text in Research Archive
• TV2, Journalist & Waaktaar, Trine (2016). 'Generasjon Prestasjon' - intervju på God Morgen Norge. [TV]. Oslo. Full text in Research Archive
• Harstad, Stine; Waaktaar, Trine & Bengtson, Mette (2016). Atferdsforstyrrelser og følelsesmessige forstyrrelser hos barn og ungdom. In Hagen, Roger & Kennair, Leif Edward Ottesen (Ed.), Psykiske lidelser. Gyldendal Akademisk. ISSN 9788205490260. p. 280–297. Full text in Research Archive
• Waaktaar, Trine (2015). Minneord Bodil Haavardsholm 1924-2014. Tidsskrift for Norsk psykologforening (Psykologtidsskriftet). ISSN 0332-6470. 52(2), p. 171–171. Full text in Research Archive
• Waaktaar, Trine (2015). Styrk sterke sider. Full text in Research Archive
• Martinsen, Kristin Dagmar; Neumer, Simon-Peter; Holen, Solveig; Waaktaar, Trine; Sund, Anne Mari & Patras, Joshua [Show all 9 contributors for this article] (2015). Transdiagnostic principles of change for anxiety and depression in youth: The EMOTION program. Full text in Research Archive
• Holen, Solveig; Martinsen, Kristin Dagmar; Neumer, Simon-Peter; Waaktaar, Trine; Sund, Anne Mari & Patras, Joshua [Show all 8 contributors for this article] (2015). Angst eller depresjon? Hvem nå man med indikert forebyggende tiltak for emosjonelle lidelser i skolen? Full text in Research Archive
• Kristin, Moksnes & Waaktaar, Trine (2015). NRK EKKO hovedsending: Ut av perfektfella. [Radio]. NRK . Full text in Research Archive
• Waaktaar, Trine (2014). Kommentar om personlighetsforskjeller hos tvillinger. [Journal]. Tvillingnytt, nr 4, 2014. Årgang. 29. Full text in Research Archive
• Haugen, Anette & Waaktaar, Trine (2014). Fra småbarnstid til pubertet. [Journal]. Tvillingnytt, nr 4, 2014 Årg. 29. Full text in Research Archive
• Waaktaar, Trine (2014). Nekrolog over psykolog Bodil Haavardsholm. Aftenposten (morgenutg. : trykt utg.). ISSN 0804-3116. Full text in Research Archive
• Waaktaar, Trine (2014). Debattinnledning og paneldeltaker på debatt på Litteraturhuset i forbindelse med konferansen: Personlighetsproblemer hos ungdom Identifikasjon og muligheter for forebygging gjennom tidlig intervensjon og behandling. Full text in Research Archive
• Waaktaar, Trine (2014). Stress kan få følger for barnets utvikling. [Internet]. nrk.no. Full text in Research Archive
• Halvorsen, Bjørn Egil & Waaktaar, Trine (2014). OnklP: - For første gang føles det som om jeg bidrar med noe. Halve Norge går rundt med «Styggen på ryggen». Hva slags nerve var det rapperen OnklP traff da han skrev om angsten sin? [Journal]. Aftenposten. Full text in Research Archive
• Waaktaar, Trine (2014). - Det vi kaller normalt er blitt veldig smalt. [Journal]. Aftenposten.no. Full text in Research Archive
• Waaktaar, Trine (2014). Tvillingtypens betydning. Kommentar fra Trine Waaktaar, førsteamanuensis, Dr.Psychol. Psykologisk institutt Universitetet i Oslo. [Journal]. Tvillingnytt. Full text in Research Archive
• Ask, Helga; Waaktaar, Trine; Seglem, Karoline Brobakke & Torgersen, Svenn (2014). Causes of co-occurring somatic, anxious and depressive symptoms in adolescents. Full text in Research Archive
• Seglem, Karoline Brobakke; Torgersen, Svenn; Ask, Helga & Waaktaar, Trine (2014). Impulsivity, delinquency and substance abuse in adolescence – Can common genetic or environmental factors explain why these traits often co-occur? Full text in Research Archive
• Hellzen, Elisabeth; Hægland, Gina; Innset, Kari; Olaisen, Kristin; Torsteinsson, Vigdis Wie & Waaktaar, Trine (2013). Psykologkompetanse på nye veier. Tidsskrift for Norsk psykologforening (Psykologtidsskriftet). ISSN 0332-6470. 50(12), p. 1223–1225. Full text in Research Archive
• Waaktaar, Trine (2012). Hvorfor er barn og unge så forskjellige når det gjelder reaksjoner på stress og belastninger i livet? Funn fra forskning på risiko- og beskyttelsesfaktorer, og noen konsekvenser for tiltak. Full text in Research Archive
• Jørgensen, Liv & Waaktaar, Trine (2012). Ensom personlighet. [Internet]. forskning.no. Full text in Research Archive
• Jørgensen, Liv & Waaktaar, Trine (2012). Hjelp til foreldre kan dempe selvmordsfare. [Internet]. RBUP Øst og Sør hjemmeside. Full text in Research Archive
• Waaktaar, Trine (2012). Mulus underverk. [Journal]. Vårt Land. Full text in Research Archive
• Waaktaar, Trine & Torgersen, Svenn (2007). Kapittel 8 Resiliens og intervensjon. In Borge, Anne Inger Helmen (Eds.), Resiliens i praksis : teori og empiri i et norsk perspektiv. Gyldendal Akademisk. ISSN 9788205359352. Full text in Research Archive
• Torgersen, Svenn & Waaktaar, Trine (2007). Resiliens som personlighetsegenskap. In Borge, Anne Inger Helmen (Eds.), Resiliens i praksis : teori og empiri i et norsk perspektiv. Gyldendal Akademisk. ISSN 9788205359352. p. 52–74. Full text in Research Archive
• Waaktaar, Trine (2019). Identitet og ungdom. Kapittel i rapport. Voksne for barn. ISSN 9788292488867. Full text in Research Archive
• Martinsen, Kristin Dagmar; Neumer, Simon-Peter & Waaktaar, Trine (2018). Prevention of anxiety and depression i school children. The development and testing of the new transdiagnostic EMOTION intervention. Universitetet i Oslo. Full text in Research Archive
• Waaktaar, Trine (2004). Stability and change in youths behaviour. An exploration of stress and resilience processes. Psykologisk Institutt, R.BUP, Nic Waals Instiutt. Full text in Research Archive

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