Objective: We tested whether a brief cognitive behavioral (CB) group and bibliotherapy prevention reduce major depressive disorder (MDD) onset, depressive symptoms, and secondary outcomes relative to brochure controls in adolescents with self-reported depressive symptoms when school personnel recruit participants and deliver the intervention.
Method: Three hundred seventy-eight adolescents (M age = 15.5 years, SD = 1.2; 68% female, 72% White) with elevated self-assessed depressive symptoms were randomized to a 6-session CB group, minimal contact CB bibliotherapy, or educational brochure control. Participants were assessed at pretest, posttest, and 6-month follow-up.
Results: CB group participants showed a significantly lower risk for major depressive disorder onset (0.8%), compared to both CB bibliotherapy (6.3%) and brochure control (6.5%; hazard ratio = 8.1 and 8.3, respectively). Planned contrasts indicated that CB group resulted in lower depressive symptom severity than brochure control at posttest (p = .03, d = 0.29) but not 6-month follow-up; differences between CB group and bibliotherapy were nonsignificant at posttest and 6-month follow-up. Condition effects were nonsignificant for social adjustment and substance use.
Conclusions: The finding that a brief CB group intervention delivered by real-world providers significantly reduced MDD onset relative to both brochure control and bibliotherapy is very encouraging, although effects on continuous outcome measures were small or nonsignificant and approximately half the magnitude of those found in efficacy research, potentially because the present sample reported lower initial depression.