Background Depression is common in young people, has a marked negative impact and is associated with self-harm and suicide. Preventing its onset would be an important advance in public health. Objectives To determine whether psychological or educational interventions, or both, are effective in preventing the onset of depressive disorder in children and adolescents. Search methods The Cochrane Depression, Anxiety and Neurosis Review Group's trials registers (CCDANCTR) were searched at the editorial base in July 2010. Update searches of MEDLINE, EMBASE, PsycINFO and ERIC were conducted by the authors in September 2009. Conference abstracts, reference lists of included studies and reviews were searched and experts in the field contacted. Selection criteria Randomised controlled trials of psychological or educational prevention programmes, or both, compared with placebo, any comparison intervention, or no intervention for young people aged 5 to 19 years-old, who did not currently meet diagnostic criteria for depression or who were below the clinical range on standardised, validated, and reliable rating scales of depression, or both, were included. Data collection and analysis Two authors independently assessed studies for inclusion and rated their quality. Sample sizes were adjusted to take account of cluster designs and multiple comparisons. We contacted study authors for additional information where needed. 1 Psychological and educational interventions for preventing depression in children and adolescents (Review)