(PS3-66) Changes in Social Information Processing and Externalizing Behavior Among Youth with Externalizing Problems During Cognitive Behavioral Therapy

Externalizing behavior (i.e., oppositional-defiant, rule-breaking, and aggressive behavior) in adolescence forms a serious risk factor for adverse outcomes later in life, such as mental health problems, criminality, and mortality (Odgers et al., 2008; Scott et al., 2017). The prognosis for adolescents with mild intellectual disabilities or borderline intellectual functioning (MID-BIF) is especially poor (Emerson et al., 2011), and these adolescents are overrepresented in child welfare and justice systems (Kaal et al., 2015; Slayter & Springer, 2011; Thompson & Morris, 2016). While many interventions aimed at reducing externalizing behavior have been developed and evaluated throughout the years, their overall effectiveness does not seem to be improving throughout the years (Weisz et al., 2019). Improving our understanding about treatment of externalizing problems in adolescence for youth with and without MID-BIF is thus of great importance.

In order to increase our understanding of interventions, it is important to not just address whether an intervention works, but also how this intervention may work. In this study, we thus investigated the working mechanisms underlying cognitive behavior therapy (CBT)-based intervention for adolescents with externalizing behavior. We focused on changes in the proximal factor (i.e. the factor directly targeted in the intervention) of social information processing (SIP; Crick & Dodge, 1994), and its relation to changes in the more distal outcome of externalizing problems. Youth participated in Think Cool Act Cool, an experimental school-based CBT-intervention for adolescents with externalizing problems (te Brinke et al., 2018). We investigated whether SIP changed following the Think Cool Act Cool intervention (RQ1), whether changes in SIP were associated with changes in externalizing problems (RQ2), and whether these changes (RQ3) and their association (RQ4) were different for adolescents with and without MID-BIF.

Ninety-nine adolescents aged 11 to 18 years participated (M_age = 14.5, SD_age = 1.5; 37.4% girls; 43% non-Dutch ethnicity), with (N = 42) and without (N = 57) MID-BIF. Self- and teacher- or staff-reported externalizing behavior (questionnaire), and social information processing (video vignette instrument) were measured before and after the intervention. We used latent change score models to answer our research questions. Analyses are currently being conducted. Our results will be presented in the poster session.