The trajectory of adolescents' depressive symptoms over the course of treatment was significantly predicted by the interaction between treatment condition and baseline self-reports of conflict with their mothers and the effect size was in the medium range (see ). presents four prototypical depression trajectories for adolescents treated with IPT-A and TAU who scored at the 75th and 25th percentile in level of conflict with mothers. Testing simple slopes for significance indicated that among adolescents who reported high levels of conflict with their mothers, treatment with IPT-A was associated with a greater acceleration in the reduction of depression symptoms (simple slope = 0.90, t = 3.94, p = 0.00), while TAU was not (simple slope = -0.26, t = -1.15, p = ns).
| Table 3Relation of Adolescents' Depressive Symptoms (HRSD) to Baseline Depressive Symptoms (HRSD), Baseline Conflict with Mother (CBQ_Mother), and Treatment Condition |
The benefits of IPT-A relative to TAU were also moderated by adolescents' baseline perceived social functioning with friends and this had a large effect size (see ). presents prototypical trajectories for different combinations of IPT-A, TAU, high (75th percentile) scores on the SAS-SR friends subscale and low (25th percentile) scores on the SAS-SR friends subscale. Testing simple slopes for significance indicated that among adolescents who reported high levels of social dysfunction with friends, treatment with IPT-A was associated with a greater acceleration in the reduction of depression symptoms (simple slope = 1.03, t = 3.94, p = 0.00), while TAU was not (simple slope = -.30, t = -1.56, p = ns).
| Table 4Relation of Adolescents' Depressive Symptoms (HRSD) to Baseline Depressive Symptoms (HRSD), Baseline Social Dysfunction with Friends (SAS_Friends), and Treatment Condition |
Adolescents' perceived social dysfunction with family members and at school also showed significant effects, but did not vary as a function of treatment (see and ). Across treatment conditions, adolescents showed less rapid reductions in depression if they reported high baseline levels of social dysfunction with family as compared to adolescents who reported low levels (see ). Adolescents who reported high baseline levels of school dysfunction also demonstrated higher levels of depression post-treatment and slower reductions in symptoms than adolescents who reported low levels (see ).
| Table 5Relation of Adolescents' Depressive Symptoms (HRSD) to Baseline Depressive Symptoms (HRSD), Baseline Social Dysfunction with Family (SAS_Family), and Treatment Condition |
| Table 6Relation of Adolescents' Depressive Symptoms (HRSD) to Baseline Depressive Symptoms (HRSD), Baseline Social Dysfunction at School (SAS_School), and Treatment Condition |
Adolescents' social dysfunction in dating was not significantly related to their depression symptom trajectories, which may be partly accounted for by the scale's poor internal reliability.
Given the number of analyses conducted, we applied the Bonferroni correction for multiple comparisons. Bonferroni correction is generally over-conservative. Perceived social dysfunction with friends continued to significantly moderate treatment outcome (p < .01), but conflict with mothers did not survive the correction. The moderators examined in this study were consistent with the theoretical approach to treatment and hypotheses were a priori. The results suggest that perceived conflict with mothers and social dysfunction with friends are at least worthy of further investigation as moderators of treatment outcome.