This study evaluated the clinical effectiveness of a programme aimed at detecting, preventing and treating postpartum depression. The French version of the EPDS was used to measure the intensity of postpartum blues on a sample of 859 women, during their stay at the obstetrical clinic. Subjects under treatment for psychological problems were excluded from the study. Mothers scoring 9 or above on the EPDS, which is predictive of pospartum depression, were randomly assigned to a prevention and a control group. Written informed consent was obtained from the subjects after the study procedure had been explained. The prevention group received a counselling session integrating supportive, educational and cognitive-behavioral components. Therapists included five female Master's Degree level students in psychology. All therapists participated in didactic and clinical training as wells as weekly supervision from the first author. All subjects were given a second EPDS with written instructions to complete the questionnaire during the period 4 to 6 weeks postpartum and return it for analysis. At four to 6 weeks, women in the prevention group had significant reductions in the frequency of probable depression, as defined by a score of 11 or above on the EPDS (30.2% vs 48.2%, chi 2 = 7.36, dl = 1, p = 0.0067) and in the intensity of depressive symptoms measured by the mean score on the EPDS (8.5, SD = 4 vs 10.3, SD = 4.4, t = 3.06, dl = 209, p = 0.0024). Mothers with a probable depression were interviewed at home and assessed using the MINI (Mini Neuropsychiatric Interview, Lecrubier et al., 1997) to diagnose major depressive episode, the SIGH-D (Structured Interview Guide for the Hamilton Depression Rating Scale, Williams, 1988) and the BDI (Beck Depression Inventory, Beck et al., 1988). The baseline depression rating scores, EPDS (mean = 13.6, SD = 4), BDI (mean = 15.7, SD = 5.9), HDRS (mean = 14.8, SD = 6), were consistent with moderate depression. No significant differences in baseline scores were observed between the two groups on all the rating scales (p < 0.001). Mothers with probable depression in the prevention group were offered a program of 5 to 8 home visits. Most of the mothers in the prevention group (72%) agreed to participate in the program. On the contrary, most of the mothers (83.3%) who scored below 9 on the first EPDS and 11 or above on the second, who so did not received the preventive counselling session, declined to participate. This suggests the importance of the preventive session in establishing therapeutic alliance. The home visits program integrated four components, supportive, educational, cognitive-behavioral and psychodynamic centred on the mother-infant relationship in terms of the mother's personal history. Therapist participated in clinical training and weekly supervision. Fifteen women (71.4%) in the study group demonstrated complete symptom remission, as defined by HDRS score below 7 after the intervention, compared with 4 women (10.5%) in the control group (chi 2 = 23, p < 0.0001). A clearly therapeutic response to treatment was observed in the treated group with a mean reduction in HDRS score of 9.5 (DS = 6.7) from baseline. The improvement in the women in the treated group, as measured by the mean HDRS scores was statistically greater than that in the control group (m = 5.35, SD = 3.5 vs m = 15.8, SD = 4.6, t = 8.24, dl = 52, p < 0.0001). Our results indicate that a program based on an intervention at obstetrical clinics and on home visits is efficacious and well accepted for prevention, detection and treatment of postpartum depression.