Effect of Sleep Disturbance on Efficacy of Esketamine in Treatment-Resistant Depression: Findings from Randomized Controlled Trials

Purpose: To evaluate the relationship of sleep disturbance to the antidepressant effects of esketamine. Materials and Methods: Two double-blind, 4-week studies randomized adults with treatment-resistant depression (TRD) to placebo or esketamine nasal spray, each with newly initiated antidepressant. Sleep was assessed using Montgomery-Asberg Depression Rating Scale (MADRS) item 4. Change in response (>= 50% decrease in MADRS total score) and remission (total MADRS score <= 12) at day 28 was examined by presence/absence of baseline sleep disturbance using logistic regression models. Impact on reported sleep disturbance (MADRS item 4 score) was examined using ANCOVA models. Results: At baseline, most patients reported disturbed sleep - moderate/severe (65.3%, 369/ 565), mild (25.3%, 143/565), or none/slightly (9.4%, 53/565) - with similar distribution between treatment groups. A higher proportion of esketamine-treated patients achieved response (OR = 2.05; 95% CI: 1.40-3.02; P < 0.001) and remission (OR = 1.81; 95% CI: 1.23-2.66; P = 0.003) at day 28 compared to antidepressant plus placebo, regardless of presence/severity of sleep disturbance. Consistent with this, sleep (MADRS item 4 score) improved in both groups after the first dose, more so with esketamine by day 8 (between group difference: P <= 0.02 at all time points). Across both treatment groups, 1-point improvement in sleep at day 8 increased the probability of antidepressant response on day 28 by 26% (OR = 1.26, 95% CI: 1.12-1.42; P < 0.001), and remission by 28% (OR = 1.28, 95% CI: 1.14-1.43; P < 0.001). Conclusion: Antidepressant efficacy of esketamine was demonstrated in patients with TRD, regardless of the presence of sleep disturbance. After 8 days of treatment and thereafter, significantly more esketamine-treated patients reported improvement in sleep versus antidepressant plus placebo.