Intravenous ketamine for postmenopausal women with treatment-resistant depression: Results from the Canadian Rapid Treatment Center of Excellence.

Women are disproportionately represented amongst samples of adults with treatment-resistant depression (TRD). Ketamine has demonstrated rapid and robust efficacy in adults with TRD. Herein, we sought to determine whether the effectiveness of intravenous (IV) ketamine was influenced by menopausal status in women with TRD. We defined premenopausal women as those under the age of 45 (n = 52), while postmenopausal women (n = 54) were those over the age of 51. Participants received four IV ketamine infusions over one-to-two weeks at a community-based center for adults with TRD. The primary outcome of interest was the change in depressive symptom severity as measured by the Quick Inventory of Depressive Symptomatology Self-Report 16 (QIDS-SR16) following four infusions, compared to pretreatment. The secondary outcomes were improvements in suicidal ideation (SI; i.e., QIDS-SR16 SI item), anxiety (i.e., Generalized Anxiety Disorder-7 scale), anhedonic severity (i.e., Snaith-Hamilton Pleasure Scale), and workplace and psychosocial function (i.e., Sheehan Disability Scale). Menopausal status did not influence overall treatment response, F (4, 280) = 1.83, p = .123, ηp2 = 0.025. Both premenopausal and postmenopausal participants demonstrated similar response rates (30% and 26%, respectively) and remission rates (both 13%) to IV ketamine treatment following four infusions. Premenopausal women experienced improvements in social function more rapidly than postmenopausal women, F (2, 174) = 1.65, p = .047, ηp2 = 0.019. Postmenopausal women experienced reduction in SI more rapidly than premenopausal women, F (4, 280) = 2.72, p = .030, ηp2 = 0.037. These preliminary post-hoc findings provide the impetus for future studies to investigate the moderational role of menopausal status, as defined by hormone levels, on response to IV ketamine for TRD.