Telephone-based nurse-delivered interpersonal psychotherapy for postpartum depression: nationwide randomised controlled trial

Background Postpartum depression and anxiety are under-addressed public health problems with numerous treatment access barriers, including insufficiently available mental health specialist providers. Aims To examine the effectiveness of nurse-delivered telephone interpersonal psychotherapy (IPT) for postpartum depression. Trial registration ISRCTN88987377. Method Postpartum women (n = 241) with major depression (on the Structured Clinical Interview for DSM-IV (SCID-I)) from 36 Canadian public health regions in rural and urban settings were randomly assigned to 12 weekly 60 min nurse-delivered telephone-IPT sessions or standard locally available care. The primary outcome was the proportion of women clinically depressed at 12 weeks post-randomisation, with masked intention-to-treat analysis. Secondary outcomes examined included comorbid anxiety, self-reported attachment and partner relationship quality. Results At 12 weeks, 10.6% of women in the IPT group (11/104) and 35% in the control group (35/100) remained depressed (OR = 0.22, 95% CI 0.10-0.46), with the IPT group 4.5 times less likely to be clinically depressed (SCID); 21.2% in the IPT group and 51% in the control group had an Edinburgh Postnatal Depression Scale (EPDS) score >12 (OR = 0.26, 95% CI 0.14-0.48), and attachment avoidance decreased more in the IPT group than in the control group (P = 0.02). Significant differences favoured the IPT group for comorbid anxiety and partner relationship quality at all time points, with no differences in health service or antidepressant use. None of the IPT responders relapsed by 36 weeks. Between-group SCID differences were sustained at 24 weeks, but not at 36 weeks. Conclusions Nurse-delivered telephone IPT is an effective treatment for diverse urban and rural women with postpartum depression and anxiety that can improve treatment access disparities.