Background. Social support theory and observational risk factor studies suggest that increased antenatal psychosocial support could prevent post-natal depression. We used empirical knowledge of risk and protective factors for post-natal depression not employed previously in order to develop and evaluate an antenatal preventive intervention.

Methods. We conducted a pragmatic randomized controlled trial in antenatal clinics. We screened 1300 primiparous women and 400 screened positive, 69 screen-positive women were untraceable or not eligible. Of 292 women who completed baseline assessment, 209 consented to randomization, of these 190 provided outcome data 3 months post-natally. ‘Preparing for Parenthood’, a structured antenatal risk factor reducing intervention designed to increase social support and problem-solving skills, was compared with routine antenatal care only. We compared the percentage depressed at 3 months after childbirth using the self-completion General Health Questionnaire Depression scale and Edinburgh Post-natal Depression Scale (EPDS), and the Schedules for Clinical Assessment in Neuropsychiatry a systematic clinical interview.

Results. Assignment to the intervention group did not significantly impact on post-natal depression (odds ratio for GHQ-Depression 1·22 (95% CI 0·63–2·39), P = 0·55) or on risk factors for depression. Forty-five per cent of the intervention group women attended sufficient sessions to be likely to benefit from intervention if effective. Attenders benefited no more than non-attenders.

Conclusions. Prevention services targeting post-natal depression should not implement antenatal support programmes on these lines until further research has demonstrated the feasibility and effectiveness of such methods. The development of novel, low cost interventions effective in reducing risk factors should be completed before further trial evaluation.