Depression in young people is a growing cause of concern, as it affects one to two percent of elementary school-aged children and three to eight percent of adolescents.
In order to determine what programs are effective in preventing depressive symptoms, researchers from Vanderbilt University conducted a meta-analysis of the last 20 years’ research on interventions targeted at preventing depressive symptoms in youth.
The study results appear in the June issue of the Journal of Consulting and Clinical Psychology, published by the American Psychological Association (APA). The findings showed that targeted interventions for those at risk for depression have greater effect sizes than universal interventions.
Thirty studies were reviewed on how well differing approaches to intervention worked in preventing depressive symptoms among children and teenagers. Three types were examined: universal, selective, and indicated programs, said researchers Jason L. Horowitz, MS, and Judy Garber, PhD, of Vanderbilt University.
Universal preventive interventions are available to all members of a particular population. Selective prevention programs are used for members of a subgroup of the population whose risk is above average. Indicated preventive interventions are used for peoples who show early signs or symptoms of a psychological disorder.
The findings of the meta-analysis showed that both selective and indicated prevention programs had a greater effect than universal programs in alleviating depressive symptoms at post-intervention and at a six-month follow up. This may be due to the fact that very large samples are necessary to show an effect in studies using universal samples. Or simply, it’s not necessarily that universal programs aren’t effective, but rather that studies may not have had the power to detect substantial effects. Moreover, universal programs, often conducted in schools in large group formats, do a good job at avoiding the stigma of singling out individuals for intervention, do not require prescreening, and have a relatively low dropout rate.
However, Horowitz and Garber showed that selective intervention programs, which target individuals who are more at risk for depression because of exposure to factors like divorce, deaths, parental depression or alcoholism, or poverty, produced a much larger effect size in reducing depressive symptoms compared to universal programs. Selective programs normally involve a more diverse sample group, are more varied in their information delivery, and target other outcomes besides depression alone (such as parent-child relationships and academic improvement).
Indicated programs, which are used for individuals who are already showing signs and symptoms of depression and are at risk of experiencing clinical depression, also showed a much greater effect size than universal programs, said Horowitz and Garber. As with selective interventions, indicated programs normally use small group formats, teach cognitive techniques emphasizing ways to reduce negative thinking, increase problem-solving skills and goal-setting abilities, and show participants how to see events in their lives from a different perspective.
Age and gender also moderated the effect of the interventions on reducing depressive symptoms. Older female adolescents participating in one of the intervention programs were more likely to have lower levels at post-intervention.
The study authors also noted the distinction between treatment and prevention effects, and showed that the studies reviewed in the meta-analysis appeared to be more effective in reducing symptoms of depression (i.e. treatment) rather than preventing the worsening of depressive symptoms. Out of 30 studies, only 4 showed evidence of an actual preventative effect.
Horowitz and Garber said in order to design better prevention programs for children and teens, future studies ought to focus on targeted populations including female adolescents, children of depressed parents, youth with higher levels of depression and/or anxiety symptoms, and youth who have been exposed to stressors, such as parental divorce, death or psychopathology. They went on to say that studies should also have longer follow up evaluations to measure whether a preventive effect occurred.