- Intervention: Depression prevention program for youth at elevated risk of serious depression.
- Key Findings: Randomized controlled trials show sizable effect in preventing clinical depression.
(Full disclosure: Martin Seligman, an author of Study 2 described below, serves on the Coalition’s Board of Advisors.)
Description of the Intervention
These are actually two closely-related group therapy interventions, evaluated in separate studies, for youth who are at elevated risk of serious depression (e.g., exhibit moderate but not severe depressive symptoms). Cognitive behavioral therapy, as delivered in these interventions, teaches them how to manage their thoughts and feelings so as to prevent depression. The following two paragraphs describe common features of the two interventions; the unique features of each intervention are described in the individual study summaries (i.e. Study 1 and Study 2) that follow thereafter.
In both interventions, the therapy is provided by 1-2 specially-trained masters or doctoral level cognitive therapists to small groups of 6-12 youths. The therapy sessions are provided over the course of 5-8 weeks, for a total of about 15 hours. Sessions teach youths (1) how depression can stem from negative/irrational beliefs about themselves (e.g. “I am a total failure because I failed that test.”); (2) how to question and replace these beliefs with more constructive interpretations of events in their lives (e.g. “One bad test performance isn’t the end of the world; I will just study harder for the next one”); and (3) how to manage stressful situations (e.g. through planning ahead and creative problem solving). The youths also complete homework assignments, which require them to monitor their thoughts and feelings, and to practice the above coping skills in their everyday lives.
The intervention evaluated in Study 1 costs approximately $1900 per youth to implement (in 2005 dollars), which includes the cost of brief training for the therapists who provide the therapy sessions. The intervention evaluated in Study 2 may cost somewhat less.
Group cognitive behavioral therapy has also been used to treat a different population – youths who are clinically depressed (as opposed to at-risk of depression). However, the evidence of its effectiveness with this different population, although promising, is not as strong.
Click the following links for a manual and workbook for the cognitive behavioral therapy intervention described in Study 1. (A similar manual is not publicly available for the intervention described in Study 2.)
EVIDENCE OF EFFECTIVENESS
Randomized controlled trial of 94 13-18 year olds at elevated risk of clinical depression because they had (1) moderate depressive symptoms, below the level of a major depressive disorder, and (2) at least one parent being treated for depression by an HMO. The youths were randomly assigned to a group that received a group cognitive behavioral therapy program – Coping With Stress – or a control group that was permitted to initiate or continue the HMO’s usual care. The cognitive behavioral therapy group could also access any other care provided by the HMO.
Results for the Cognitive Behavioral Therapy group 26 months after completion of the intervention (versus the control group):
- 36% less likely to be diagnosed as having experienced a major depressive episode during the past 26 months (21% of the cognitive behavioral therapy group had an episode vs. 33% of the control group).
- A significant reduction in the number and frequency of depressive symptoms the youth were experiencing at the end-of-intervention and one-year follow-ups, but this effect disappeared at the 26-month follow-up.
- No significant effect on the incidence of nonaffective disorders (e.g. substance abuse or eating disorders).
Discussion of Study Quality (click here for a glossary of terms)
- The study had low attrition: Outcome data were collected for 83% of the original sample at the 26-month follow-up.
- The study measured outcomes using an intention-to-treat analysis.
- Depression outcome data were collected using diagnostic interviews conducted by trained masters-level psychologists who were blind as to whether youths were in the cognitive behavioral therapy or control group.
- Depression outcomes were measured using well-established diagnostic instruments (e.g. Schedule for Affective Disorder and Schizophrenia for School-Aged Children: Epidemiological Version).
- Prior to the intervention, there were no significant differences between the cognitive behavioral therapy and control groups.
- Study Limitation: The control group did not receive an attention placebo (i.e., an ineffectual but harmless treatment). Attention placebo controls help protect against the possibility, which sometimes arises in mental health studies, that the intervention group has superior outcomes because they believe they are receiving an effective treatment, rather than because the intervention is truly effective.
Randomized controlled trial of 231 college freshman identified as being at elevated risk for depression through a written survey and a diagnostic interview. Students were randomly assigned to a group that received group cognitive behavioral therapy (which included relaxation training) from doctoral level therapists during the first semester of their freshman year, or a control group that did not. Therapists used the Apex Project manual for group leaders, and were assisted by a co-trainer (e.g. a fellow therapist or a clinical psychology doctoral student) during group sessions. They also met individually with each participant six times over a two year period.
Results of Cognitive Behavioral Therapy 3 years after completion of the intervention (versus the control group):
- 39% less likely to have experienced a moderate depressive episode (19% of the intervention group had such an episode vs. 31% of the control group).
- No significant effect on the incidence of more severe depressive episodes, though there was a non-significant trend favoring the Cognitive Behavioral Therapy group (17% vs. 21%).
- 33% less likely to have been diagnosed with a moderate or severe anxiety disorder (14% vs. 21%).
- The above effects did not diminish over the course of the three–year follow-up.
Discussion of Study Quality (click here for a glossary of terms)
- The study had low attrition and a long-term follow-up: 86% of the sample was interviewed at the three-year follow-up.
- Prior to the intervention there were no significant differences between the cognitive behavioral therapy and control groups.
- Outcome data were collected using diagnostic interviews conducted by trained researchers who were blind as to whether students were in the cognitive behavioral therapy or control group.
- Depression outcomes were measured using well-established diagnostic instruments (e.g. the Structured Clinical Interview for the Diagnostic Statistical Manual of Mental Disorders-III-R).
- While the study does not specifically say so, it appears to have measured outcomes using an intention-to-treat analysis.
- Study Limitation: The control group did not receive an attention placebo (i.e., an ineffectual but harmless treatment). Placebo controls help protect against the possibility, which sometimes arises in mental health studies, that intervention participants have superior outcomes because they believe they are receiving an effective treatment, rather than because the intervention is truly effective.
One other randomized controlled trial of Group Cognitive Behavioral Therapy for youth at risk of depression has been conducted, and its results are consistent with those found in the studies above. However, we do not describe it here because it falls outside this site’s criteria (as a result of differential attrition between the intervention and control groups).
(Click on linked authors’ names for their contact information)
- Clarke, Gregory N, Mark Hornbrook, Frances Lynch, Michael Polen, John Gale, William Beardslee, Elizabeth O’Connor, and John Seeley. “A Randomized Trial of a Group Cognitive Intervention for Preventing Depression in Adolescent Offspring of Depressed Parents.” Archives of General Psychiatry, Vol. 58; December 2001, pp 1127-1134.
- Seligman, Martin E.P., Peter Schulman, Robert J. DeRubeis, and Steven D. Hollon. “The Prevention of Depression and Anxiety.” Prevention & Treatment, Vol. 2 Article 8, 1999.