Sleep alterations in treatment-resistant depression patients undergoing ketamine treatment.

Background: This study examines self-reported sleep alterations in treatment-resistant depression (TRD) inpatients following intravenous ketamine administration.

Methods: This is a post-hoc analysis of a naturalistic observational study, which enrolled 28 inpatients with treatment-resistant major depressive disorder and analyzed self-reported sleep changes (items 1-4; 'insomnia', 'nighttime restlessness', 'early morning waking', 'hypersomnia') in Inventory of Depressive Symptomatology 30-item (IDS SR-30) in responders and non-responders stratified per Montgomery-Åsberg Depression Rating Scale (MADRS) during short-term ketamine treatment.

Results: Responders, as well as non-responders, did not experience significant changes in IDS SR-30 sleep items ('insomnia', 'nighttime restlessness', 'early morning waking', 'hypersomnia') (p's > 0.05) at 7-day follow-up after eight intravenous ketamine infusions as compared to baseline.

Conclusion: Neither responders, nor non-responders reported any significant alterations in sleep patterns during ketamine infusions. These findings are not in line with current literature, as so far modest improvements in sleep during ketamine treatment have been reported. Results should be interpreted with caution, primarily due to the small sample size.