Observational · 2026
Sleep and appetite changes were the most reported new symptoms during ketamine infusions for depression
- Original title
- Treatment-emergent psychiatric adverse events in patient-reported outcomes during ketamine use for major depressive disorder: a retrospective analysis.
- Authors
- Kwaśny A, Wilkowska A, Pastuszak M, et al.
- Journal
- Pharmacological reports : PR, 2026
- Molecules
- Ketamine
- Conditions
- Treatment-resistant depression, Depression
- Participants
- 28
- Evidence grade
- Low
- Source
- Read the original paper
The question
Which new psychiatric symptoms do patients themselves report while receiving repeated ketamine infusions for depression that has not responded to other treatments?
What they did
Researchers went back over data from an observational study of 28 hospital inpatients with treatment-resistant depression. Each person received 8 ketamine infusions added on top of their existing medication. Patients filled out a standard self-report depression questionnaire (the Inventory of Depressive Symptomatology Self-Report 30). The team counted symptoms that were absent at the start but appeared during treatment, called treatment-emergent adverse events.
What they found
Sleep problems were the most consistent new complaint. Trouble sleeping at night increased by the 7th infusion and was still reported at follow-up by 5 people, and early waking was reported by 3 to 4 people across time points. Appetite and weight changes also appeared, with both increased appetite (7 people) and decreased appetite (6 people) peaking at the 3rd infusion and continuing at lower rates at follow-up. Mood, thinking and most bodily symptoms were rare (2 to 4 people or fewer), and new suicidal thinking was reported by 1 person at the 3rd infusion and at follow-up.
The fine print
This was a retrospective analysis of just 28 inpatients, with no placebo or comparison group, so it cannot show whether these symptoms were caused by ketamine, by the depression itself, or by other medications. Symptoms were counted from a self-report depression questionnaire rather than a dedicated side-effect tool, and the numbers involved are very small. Follow-up length is not described in the abstract, and this summary is based on the abstract alone.
What it means
In this small group, the new symptoms patients noticed during repeated ketamine infusions were mostly about sleep, appetite and weight rather than mood or thinking, but larger controlled studies are needed before drawing firm conclusions about ketamine’s psychiatric safety.
Evidence grade: Low. A small retrospective look back at an uncontrolled observational study of 28 inpatients, with no placebo group and self-reported symptom checklists.
This summary is based on the study’s published abstract.