A Cochrane review [Abstract] 1 included 83 studies with children and adolescents. The majority of trials (67) were carried out in school settings, 4 in clinical settings, 3 in the community and 4 in mixed settings. 29 trials were carried out in unselected populations and 53 in targeted populations. For the primary outcome of depression diagnosis at medium-term follow-up (up to 12 months), the risk of having a diagnosis of depression was reduced with an intervention compared to no intervention (risk difference (RD) -0.03, 95% CI -0.05 to -0.01; P value = 0.01; 32 trials, n=5 965, moderate quality evidence). Depression symptoms (self-rated) reduced slightly at the post-intervention time point (standardised mean difference (SMD) -0.21, 95% CI -0.27 to -0.15; P value < 0.0001; 70 trials, n=13 829). This effect persisted up to 3 months (SMD -0.31, 95% CI -0.45 to -0.17; P value < 0.0001; 16 studies, n=1558) and 4 to 12 months (SMD -0.12, 95% CI -0.18 to -0.05; P value = 0.0002; 53 studies, n =11 913), but was no longer evident at the long-term follow-up (moderate quality evidence). For trials implemented in universal populations there was no effect for depression diagnosis (RD -0.01, 95% CI -0.03 to 0.01) and a small effect for depression symptoms (SMD -0.11, 95% CI -0.17 to -0.05). For trials implemented in targeted populations there was a statistically significantly beneficial effect of intervention (depression diagnosis RD -0.04, 95% CI -0.07 to -0.01; depression symptoms SMD -0.32, 95% CI -0.42 to -0.23).
Comment: The quality of evidence is downgraded by study limitations (unclear allocation concealment and lack of blinding), and by inconsistency (unexplained variability in results).
Primary/Secondary Keywords