Efficacy trial of a brief cognitive-behavioral depression prevention program for high-risk adolescents: effects at 1- and 2-year follow-up.

Major depression is a common, recurrent, and impairing condition that increases risk for future suicide attempts, academic failure, interpersonal problems, unemployment, substance abuse, and delinquency (Klein, Torpey, & Bufferd, 2008). Because less than one third of depressed youth receive treatment (Newman et al., 1996) it is crucial to develop prevention programs for this psychiatric condition. At present, cognitive-behavioral (CB) interventions that primarily focus on reducing negative cognitions have the most empirical support. CB interventions have produced significantly greater reductions in depressive symptoms than assessment-only control groups in universal trials (Jaycox, Reivich, Gillham, & Seligman, 1994; Shochet et al., 2001; Spence, Sheffield, & Donovan, 2003), in selected trials with high-risk youth (Seligman, Schulman, & Tryon, 2007), and in indicated trials involving youth with elevated depressive symptoms (Clarke et al., 1995, 2001; Garber et al., 2009; Stice, Burton, Bearman, & Rohde, 2006). Although these interventions typically produce significantly greater reductions in depressive symptoms than observed in assessment-only control groups, effects rarely persist through 1- and 2-year follow-up. A meta-analytic review found that only 4 out of 17 trials of CB depression prevention programs produced effects that remained significant at 1-year follow-up, with an average effect size of only an r = .08 across the 17 trials (Stice, Shaw, Bohon, Marti, & Rohde, 2009). For instance, Clarke et al. (1995) found that a 15-session group CB intervention resulted in greater reductions in depressive symptoms by posttest compared to an assessment-only control condition for adolescents with depressive symptoms, though this effect was nonsignificant at 1-year follow-up. CB interventions have significantly reduced risk for future onset of major depression during follow-up in some trials (Clarke et al., 1995; 2001; Stice, Rohde, Seeley, & Gau, 2008) but not others (Gillham, Hamilton, Freres, Patton & Gallop, 2006; Seligman, Schulman, DeRubeis, & Hollon, 1999; Seligman et al., 2007; Sheffield et al., 2006). Garber and associates (2009) found that their group CB intervention significantly reduced risk for onset of depressive episodes relative to assessment-only controls over a 6-month period during which booster sessions were administered monthly. Although several CB prevention programs have produced promising findings, the long duration of these interventions makes them challenging to implement. In addition, we believe that adolescents are more likely to benefit from prevention programs that have only a few simple concepts to remember. In line with this thesis, a meta-analytic review of obesity prevention programs found that programs that focus on fewer concepts produced significantly larger effects than those that focus on numerous concepts (Stice, Shaw, & Marti, 2006). It is possible that a similar process occurs for depression prevention programs. Thus, we developed a brief 6-session group CB prevention program that focused exclusively on reducing negative cognitions and increasing pleasant activities among individuals with elevated depressive symptoms. An earlier report from this indicated depression prevention trial found that participants assigned to this program showed significantly greater reductions in initial depressive symptoms and psychosocial impairment and reduced risk for onset of future major depression than educational brochure controls through 6-month follow-up (Stice, Rohde et al., 2008). The present report describes the effects for this group CB program through 1- and 2-year follow-up. Another gap in the literature is that few trials have compared CB prevention programs to placebo or alternative interventions. This comparison is necessary to determine whether effects result because of the specific therapeutic procedures theorized to produce intervention effects or nonspecific effects common to all group-based interventions (e.g., therapeutic alliance, group cohesion, installation of hope, participant expectancies). Indeed, one criterion for establishing that an intervention is efficacious is that it outperforms a placebo or alternative intervention (American Psychiatric Association, 1995). Five trials have compared CB depression prevention programs to alternative interventions. Merry, McDowell, Wild, Bir, and Cunliffe (2004) found that a universal CB program produced greater reductions in depressive symptoms at posttest than an arts and crafts intervention, though effects were nonsignificant by 18-month follow-up. Stice et al. (2006) found that participants assigned to a CB program, supportive expressive therapy, CB bibliotherapy, expressive writing, and a journaling intervention showed greater reductions in symptoms than assessment-only controls at posttest, but only bibliotherapy produced effects that persisted through 6-month follow-up. CB participants showed greater symptom reductions relative to only journaling participants and only at posttest. Bibliotherapy participants showed greater symptom reductions than expressive writing participants at 6-month follow-up. Gillham et al. (2007) found that a CB depression prevention program did not produce greater symptom reductions than a nonspecific comparison intervention or an assessment-only control condition. Horowitz, Garber, Ciesla, Young, and Mufson, (2007) found that both a CB and an interpersonal therapy intervention reduced symptoms relative to assessment-only controls through posttest, but not 6-month follow-up; there were no significant differences between the two interventions. An earlier report from the present trial (Stice, Rohde et al., 2008) found that group CB participants showed greater symptom reductions at posttest than supportive expressive and CB bibliotherapy participants, though effects were nonsignificant by 6-month follow-up. Supportive expressive and bibliotherapy participants both showed greater symptom reductions than assessment-only controls through 6-month follow-up, with supportive expressive participants showing greater reductions than bibliotherapy participants at posttest, implying that nonspecific factors contribute to CB intervention effects or that interventions with either general group nonspecific therapeutic factors or CB material produce effects. Thus, trials provide limited evidence that group CB depression prevention programs significantly outperform alternative interventions. Further, most of these trials used brief follow-up periods. The present report compared the effects of the brief group CB prevention program against a supportive expressive intervention that was intended to control for nonspecific therapeutic factors and a CB bibliotherapy that was intended to control for CB content at 1- and 2-year follow-up. The goals of supportive expressive interventions, which have been used in prior depression treatment trials (Brent et al., 1997; Shaw, 1977), are to establish and maintain rapport, provide support, and help the client identify and express emotions. Bibliotherapy refers to the prescription of books for the treatment of a disorder. We thought it vital to compare the apparent intervention of choice for the prevention of depression (i.e., group CB) to bibliotherapy because the latter is much less expensive and easier to disseminate. Our primary outcomes were reductions in depressive symptoms, risk for onset of major/minor depressive disorder, and improvements in social adjustment. We targeted adolescents with depressive symptoms because meta-analytic reviews found that selected and indicated programs targeting high-risk youth produce larger effects than universal programs offered to unselected adolescents (Horowitz & Garber, 2006; Stice et al., 2009). In theory, youth struggling with subdiagnostic depression may be more likely to engage in the prevention program because they are more motivated to change. It may also be easier to acquire intervention skills when they can be applied to current symptoms. We focused on adolescents with depressive symptoms because risk factor studies have found that this is typically the most potent predictor of future onset of major depression (Lewinsohn et al., 1994; Seeley, Stice, & Rohde, 2009; Weissman et al., 1992) and this population has responded to CB prevention programs (Clarke et al., 1995, 2001; Garber et al., 2009).