Scientific abstract

Willful control of thoughts, emotions and behavior is an intrinsically human capacity and a prerequisite for adaptive functioning. This capacity relies on complex higher-order mental processes often denoted as executive functions (EF). Several brain regions contribute to EF, but the prefrontal cortex plays a crucial role. Given the extensive connectivity between the frontal lobes and other brain areas, executive dysfunction (ED) can result from a wide range of conditions affecting brain functioning. ED is particularly common following acquired brain injury (ABI).

Executive control is especially called for in non-familiar situations, in performing activities involving many sub-goals, or when the circumstances change, eliciting a demanding for volitional adjustment of thinking, behavior and/or emotions in order to adapt. In daily life, ED is thus often indicated by problems with planning, strategy application, self-regulation, inhibition, goal-directed behavior, initiation of activity, regulation of emotions, and self-awareness. These impairments may have devastating consequences for the individual’s ability to independently perform daily life activities.

Accumulating evidence shows that structured training in awareness and compensatory strategy application, such as Goal Management Training (GMT), is effective in improving EF. GMT is a standardized metacognitive rehabilitation program, particularly aiming at improving sustained attention and problem solving skills, through the training of verbally mediated metacognitive strategies. It is a top-down approach, tying taught strategies to the individual’s daily life activities and goals.

Although GMT’s efficacy has been demonstrated in a number of samples, previous GMT studies involving patients with ABI have several limitations, particularly related to study-design and sample size, long-term effects, and lack of knowledge about predictors of outcome. The main aim of the present randomized controlled trial (RCT) was therefore to investigate the efficacy of GMT in patients with chronic ABI, compared to an active control treatment (Brain Health Workshop). A second aim was to identify possible predictors of treatment outcome. A new module addressing emotional dysregulation was implemented in GMT, to investigate whether the intervention could improve psychological distress in daily life. Both groups also received external cueing (i.e. short message service) in order to facilitate goal management. The study applied a repeated-measures design across three time points; baseline, post-intervention, and six-month follow-up. Neuropsychological tests and questionnaires assessing EF, psychological distress, and quality of life (QoL) were administered at all three time-points.

The findings in Paper I demonstrated that the participants receiving GMT showed significant improvement of self-reported everyday EF, compared to the active control group. Improvement for both groups was observed on the majority of the neuropsychological tests, but improved performance for executive attention was most prominent in the GMT group. The strongest effects observed six-month post-treatment, suggest that strategies learned in GMT were applied and consolidated in everyday life.

In Paper II, GMT-participants reported significant improvement of emotional regulation skills in everyday life and QoL at six-month follow-up, compared to the active control group. However, no significant intervention effects on measures of psychological distress were observed.

The results in Paper III, exploring predictors of treatment outcome, indicated that higher age and higher IQ emerged as nonspecific predictors, and working memory and planning ability moderated or mediated outcomes. Irrespective of intervention type, higher levels of self-reported symptoms predicted less benefit. This finding could underscore that cognitive, emotional, and/or psychological functioning have a general influence on intervention efficacy, across interventions. Of interest, the observed improvement of inhibitory control was GMT-specific.

In summary, the study confirms that GMT is an efficient rehabilitation protocol, producing lasting benefits for EF, including emotional regulation, even many years’ post-injury. Of particular interest, and in line with the theoretical underpinnings of GMT, the results support a specific improvement of cognitive inhibitory control. Still, the findings underscore that interventions targeting specific cognitive domains, such as attention or working memory, also need to take into account the patients’ overall cognitive and emotional functioning in order to facilitate the best possible outcomes.

 

 

Publisert 16. nov. 2017 13:58 - Sist endret 16. nov. 2017 14:03