A Cognitive-Behavioral Program for the Prevention of Depression in at-Risk Adolescents: Mediators of Effects

Several programs have been found to prevent depressive symptoms in youth (Merry et al., 2011). In particular, Garber et al. (2009) reported that adolescents randomized to a cognitive-behavioral prevention (CBP) program had significantly fewer episodes of depression compared with youth in usual care (UC); this effect was moderated by current parental depression. For adolescents whose parents were not depressed at intake, CBP was significantly more effective in preventing depression than UC, whereas among youth whose parents were depressed at baseline, the CBP and UC conditions were not significantly different. The current study tested whether negative cognitive style mediated the effects of CBP on depressive symptoms.

Method: Participants were 316 adolescent (13-17 years) offspring of parents with current or past depressive disorders; adolescents had histories of depression, current elevated depressive symptoms, or both but did not meet criteria for a current depressive disorder. The CBP program consisted of 8 weekly group sessions followed by 6 monthly continuation sessions.

Measures of cognitive style included the Children’s Attributional Style Questionnaire (CASQ), the Hopelessness Scale (HS), the Dysfunctional Attitudes Scale (DAS), and the Rosenberg Self-Esteem Scale (RSES). Depressive symptoms were measured using the Center for Epidemiological Studies-Depression Scale (CES-D).

A cross-lagged panel model (Cole & Maxwell, 2003) was used to test whether CBP’s effect on depressive symptoms at post-continuation (9 months) was indirect through improvements in the cognitive style latent factor at the post-acute phase assessment (3 months). Confidence intervals for the indirect effects were calculated using the Monte Carlo method with 50,000 simulations (Preacher & Selig, 2012). 

Results and Discussion: Confirmatory factor analyses indicated that a unidimensional conceptualization of cognitive style was acceptable (NNFIs .954-1.00 and RMSEAs .000-.048), and showed strong longitudinal invariance over time. Baseline parental depression moderated the effect of CBP on 3-month levels of cognitive style (path a). Among youth whose parents were not depressed at baseline, there was an indirect effect on 9-month levels of depressive symptoms through 3-month levels of cognitive style: ab=-1.70, 95% CI [-3.71, -0.13]. There was no evidence of an indirect effect among youth whose parents were depressed at baseline, nor evidence of reverse mediation of an indirect effect on cognitive style through depressive symptoms, regardless of parent depression status (RMSEA=.044, NNFI=.962). Thus, the CBP program worked, in part, through changing negative cognitions. Methodological issues regarding moderated mediation using multiple indicators of the mediator will be discussed.