ACT your way: A transdiagnostic treatment approach for multiple disorders in transitional-age youth

The developmental period of late adolescence to early adulthood is a period characterized by significant variability and change. Due to these significant changes, transitional-age youths (i.e., youths aged 15 to 25; TAY) are at great risk of developing psychological problems. Despite the evidence that the prevalence of psychological disorders among TAY is high, TAY are much less likely to receive treatment for their psychological problems compared to other age groups (e.g., adolescents or adults). In addition, there are few interventions specifically developed for this specific age group. Nowadays, TAY are often treated with interventions developed for either adolescents or adults. These interventions often do not meet TAY’s needs and are therefore not developmentally sensitive. Moreover, most of these interventions mainly focus on reducing symptoms of one specific disorder, instead of targeting transdiagnostic mechanisms underlying symptoms of multiple disorders. By doing so, these interventions are less suitable for TAY with comorbid, chronic or recurrent psychological problems. Hence, we propose ACT your way, a transdiagnostic treatment specially developed for TAY. Due to its strong focus on identity and autonomy development, the intervention fits well with the developmental needs of this age group. ACT your way is based on the principles of Acceptance and Commitment Therapy (ACT). The main purpose of ACT is to promote psychological flexibility, a transdiagnostic mechanism which can be defined as an individual’s acceptance of negative feelings, thoughts and physical sensations and the ability to choose an adaptive (and more effective) response. Meta-analyses including adults show that ACT is an effective treatment for individuals with depression, anxiety and other types of psychopathology. In addition, a pilot study that has been conducted in TAY with recurrent or chronic depression shows promising effects.

Considering this, the goal of the current study is to examine the (cost-)effectiveness of ACT your way, by comparing ACT your way with treatment as usual (TAU) in TAY (aged 15 to 25) with various psychopathology (including chronic, comorbid and recurrent diagnoses). We expect ACT your way to be more effective and cost-effective compared to TAU. In addition, we will examine several moderators and mediators to study for whom the intervention is effective and how the intervention works.

We expect that ACT your way is more (cost-)effective than TAU and shows more improvements related to (1) psychological flexibility, (2) psychopathology, (3) quality of life, (4) global functioning, (5) individual and societal functioning, (6) emotion regulation, (7) personality problems, (8) autonomy, (9) stress, (10) perfectionism, (11) self-esteem and (12) self-compassion at the short term (immediately after treatment) but also at the long term (after 6 months). Furthermore, we expect better (13) treatment alliance, (14) less drop-out and (15) more treatment satisfaction of the adolescent/young adult since ACT your way is more attuned to their needs.

Six multiple informant (adolescent/young adult, parent, therapist) assessments will be conducted: prior to treatment (pre-treatment), after 3 sessions (mediator 1), after 6 sessions (mediator 2), after 9 sessions (mediator 3), immediately after treatment (post-treatment) and 6 months after treatment (6-month follow-up).

ACT your way is an intervention based on Acceptance and Commitment Therapy (ACT), that is not directed primarily at symptom reduction but at changing the underlying mechanism of psychopathology, namely psychological inflexibility. ACT you way consists of twelve weekly sessions.