Sex Differences in the Antidepressant and Neurocognitive Effects of Nonconvulsive Electrotherapy in Patients with Treatment-Refractory Depression.

Objective: The objective of this study was to examine sex differences in the antidepressant and neurocognitive effects of adjunctive nonconvulsive electrotherapy (NET) in patients with treatment-refractory depression (TRD), which has not yet been thoroughly investigated.

Methods: The study enrolled 20 patients with TRD, comprising 11 males and 9 females, who underwent a series of 6 NET sessions. The 17-item Hamilton Depression Rating Scale (HAMD-17) was used to assess depressive symptoms, response, and remission at baseline and after the first, third, and sixth NET sessions. The Wisconsin Card Sorting Test (WCST) was used to assess neurocognitive function at baseline and after the sixth NET session.

Results: After completing 6 NET sessions, female patients experiencing TRD exhibited a higher inclination toward achieving an antidepressant response (77.8% vs. 45.5%,  = .197) and antidepressant remission (22.2% vs. 0%,  = .189) when compared to their male counterparts. No significant differences were observed in changes in the HAMD-17 and WCST subscale scores (all > .05), including completing classification number, total error number, persistent error number, and random error number between males and females. Additionally, no significant correlations were observed between baseline WCST subscale scores and changes in HAMD-17 scores or endpoint scores, irrespective of sex (all > .05).

Conclusion: These pilot findings suggest that female patients with TRD exhibited increased rates of achieving antidepressant response and remission after undergoing NET. However, further studies should be conducted to confirm these findings.