Impact of sex differences on the association between clinical predictors and electroconvulsive therapy outcomes results from the Dutch ECT Consortium (DEC)

Objective: Medical research historically underrepresented women, often generalizing findings from men to women. Sex-specific analyses could enhance guideline accuracy and support personalized care. Electroconvulsive therapy (ECT) is highly effective in major depressive disorder (MDD), however research regarding the impact of sex on ECT efficacy is scarce. This study aimed to explore sex differences in ECT outcome and clinical variables associated with ECT outcome to replicate and extend previous research.
Methods: Clinical data from sites participating in the Dutch ECT Consortium. Remission was defined as a post-ECT Hamilton Depression Rating Scale (HDRS) score of 7 points or below. Clinical variables influencing ECT outcome were selected based on prior research.
Results: Data included 1892 MDD patients (N = 1210 women), with a mean age of 59.5 years. Remission rate did not differ among sexes (χ²(1) = 2.0, p  = 0.17). We observed significant sex-related interaction effects for duration of index episode (χ²(1) = 4.36, p = 0.04) and for failed psychotherapy in the current episode (χ²(1) = 4.56, p = 0.03). Women's remission rates remained stable regardless of episode duration, while men's remission likelihood decreased with longer episodes. Women treated with prior evidence-based psychotherapy showed lower remission rates than men.
Conclusion: This study highlights that ECT is equally effective for both men and women. The tentative sex-related interaction effects are of clinical interest though modest in size. Clinicians must understand sex differences in ECT outcomes and the potential for sex-specific side-effects to make a fully informed decision.