This study is the first to describe reductions in occipital cortex GABA levels in the postpartum period, a time of increased vulnerability to mood disturbances in women. The concomitant reduction in peripheral ALLO levels provides further evidence of alterations in the balance between cortical excitation and inhibition during the puerperium. Women with PPD may represent a subgroup of women who fail to adequately adapt to this alteration in the neuroendocrine milieu.

Taken together with previous 1H-MRS data showing abnormalities in occipital cortex GABA concentrations in several affective disorders, our preliminary finding that nicotine modulation of GABA levels varies by sex provides a further rationale for investigating the impact of nicotine on central GABAergic function as a potential risk factor for women to experience depressive symptoms during smoking cessation.

Rationale Postpartum depression (PMD) occurs in roughly 10% of postpartum women and negatively impacts the mother and her offspring, but there are few placebo-controlled studies of antidepressant treatment in this population. Objectives To compare the selective serotonin reuptake inhibitor (SSRI) sertraline to placebo for treating PMD. Methods This was a single-center, 6-week, randomized double-blind placebo-controlled trial of sertraline with a one-week placebo lead-in. Participants (n=38) were women with depression onset within 3 months of delivery; a subset (n=27) met strict DSM-IV criteria for PMD (onset within 4 weeks of delivery). Participants were prescribed sertraline 50 mg or placebo daily, to a maximum of 200 mg/day. Primary outcome variables were the Hamilton Depression Rating Scale (HAM-D) and Clinical Global Impressions (CGI) scores, which were used to determine rates of response and remission. Results Sertraline produced a significantly greater response rate (59%) than placebo (26%) and a more than 2-fold increased remission rate (53% vs. 21%). Mixed models did not reveal significant group by time effects, although in the subset of women who met DSM-IV criteria, there was a statistically significant group by time effect for the HAM-D, Hamilton Anxiety Rating Scale (HAM-A) and CGI. Conclusions Women with PMD are more likely to have a remission of their depression with sertraline treatment, a finding that is more pronounced in women who have onset of depression within 4 weeks of childbirth. These data support the continued use of 4 weeks for the DSM-5 postpartum onset specifier for major depressive disorder.