The impact of perceived interpersonal functioning on treatment for adolescent depression: IPT-A versus treatment as usual in school-based health clinics.

Adolescent depression is a significant public health problem with approximately 1 in 5 adolescents experiencing a depressive episode at some point during their teenage years (Lewinsohn, et al., 1993). Progress in the development of efficacious treatments for adolescent depression has been substantial. However, even the best treatments for adolescent depression are effective in only 50-70% of youth (e.g. TADS Team, 2004). There is a call for the field to move beyond determining what treatments work to identifying which treatments work for whom (Insel, 2009). Identifying patient characteristics that interact with or moderate treatment can help guide clinicians in selecting a treatment that will lead to better management of depression. Interpersonal psychotherapy for depressed adolescents (IPT-A; Mufson, Dorta, Moreau, & Weissman, 2004) aims to reduce adolescents' depressive symptoms by helping them improve their relationships and communication skills. Adolescents treated with IPT-A demonstrated fewer depressive symptoms and better social and global functioning post-treatment than adolescents in control conditions (Mufson, Dorta, Wickramaratne, et al., 2004; Mufson, Weissman, Moreau, & Garfinkel, 1999; Rossello & Bernal, 1999). Some moderators of treatment outcome have already been identified: IPT-A has been found to be significantly more effective than treatment as usual (TAU) for adolescents who were older (ages 15-18), had higher levels of depression, poorer general functioning, or comorbid anxiety at initiation of treatment (Mufson, Dorta, Wickramaratne, et al., 2004; Young, Mufson, & Davies, 2006). Adolescents who were younger (ages 12-14), had lower levels of depression, higher general functioning, and no comorbid anxiety responded comparably to IPT-A and TAU. The goal of the current study was to examine whether depressed adolescents' pre-treatment perceived interpersonal functioning moderated treatment outcome with IPT-A and TAU in school-based health clinics. Interpersonal stressors are among the strongest predictors of depression (Rudolph, et al., 2000). Depressed adolescents are more likely to have conflictual and unsupportive relationships with parents (Sheeber, et al., 2007), display poor communication patterns with friends, report having unsupportive friendships, and experience teasing and bullying (Allen, et al., 2006; Klomek, et al., 2007). Given IPT-A's emphasis on improving interpersonal difficulties that may be contributing to or exacerbating depression, we examined the impact of adolescents' initial reports of interpersonal functioning (conflict with their mothers, and social functioning at school, with friends, family, and dating) on the course and outcome of treatment. Because IPT-A specifically targets adolescents' interpersonal difficulties and previous analyses indicated that IPT-A is particularly effective for more symptomatic and impaired adolescents, we hypothesized that IPT-A would be more effective than TAU in treating depressed adolescents with poor perceived interpersonal functioning.