Psychological interventions may be effective in the treatment of subclinical depression and prevent progression to major depression, but more high quality evidence is needed, a meta-analysis has concluded. Eighteen randomised controlled trials met the inclusion criteria for the meta-analysis. The 1,913 participants were adults with ‘clinically relevant depressive symptoms’ identified either by using a self-rating depression questionnaire e.g. CES-D score 8-15 or a diagnostic interview. There were 947 patients in the treatment group and 966 in the control group.