Cognitive behavioural therapy best prevents postpartum depression

Multiple birth is associated with a doubling of the risk of maternal mental health disorders. This investigation recognises the substantial impact that maternal depression can have on successful parenting, child health, and family functioning. The authors explore whether a supportive/educational midwifery intervention can reduce the risk of postpartum depression (PPD). I provide this commentary believing that nurse midwives bring substantial value to the care of women with twins (Ellings et al., Obstet Gynecol 1993;81:387–91). Unfortunately, the author’s results are not conclusive. Women received care in an antenatal multidisciplinary twin clinic with specialist midwives and additional preand postnatal visits. Participants and spouses in the intervention group attended a series of educational programmes on parenting multiples. The intervention group reported greater maternal wellbeing, family support, mood, self-confidence, and felt better prepared for parenting; however, the primary outcome was a reduction in maternal depression as measured by the Edinburgh Postnatal Depression Scale (EPDS). The mean maternal EPDS was lower at 26 weeks postpartum, but it was not significantly different from the control group scores. Nor were there any differences in maternal anxiety or parenting stress. Unfortunately, the study was substantially underpowered. A recent meta-analysis of 19 studies (5806 patients), including seven designed to prevent PPD, reviewed the efficacy of cognitive behavioural therapy (CBT) or interpersonal psychotherapy (Cuijpers et al., Am J Psychiatry 2008;165:1272–80). These interventions were associated with an overall 22% reduction in the incidence of depressive disorders. The number needed to treat (NNT) to prevent one depressive disorder was 22. Psychological interventions worked best for those at highest risk, and interpersonal psychotherapy may be slightly more effective than CBT. It concluded that prevention of depressive disorders is possible, and is associated with an enormous reduction in public health burden. Another relevant study screened first-time pregnant women and randomised the women who screened positive to a Preparing for Parenthood educational programme designed to increase social support and problem-solving skills. Assignment to the intervention group did not significantly affect postnatal depression at 3 months (Brugha et al., Psychol Med 2000;30:1273–81). In the absence of a specific therapy designed to reduce maternal stress, the likelihood of preventing PPD with education and support alone is probably low. Another systematic review of 15 trials (7697 women) offering psychological interventions revealed a non-significant reduction (RR 0.81, 95% CI 0.65–1.02) in the frequency of depressive disorders. The most effective intervention was intensive postpartum support provided by a health professional (RR 0.68, 95% CI 0.55– 0.84), and individually based interventions were more effective than group interventions (Dennis, BMJ 2005;331:7507–15). Women carrying twins are at high risk for PPD and good candidates for preventative interventions. The development of novel, cost-effective interventions deserves further research attention. This intervention may have shown greater efficacy by focusing on even higher risk multiples such as those with a history of mental illness, prior fetal or infant death, or antenatal depression. CBT interventions designed to reduce postnatal maternal stress and/or anxiety appear to be more effective than education-based interventions. Midwives involved in preand postnatal care could absolutely be trained to provide CBT, and are likely to be more acceptable to parturients than either psychologists or psychiatrists.