Neuropsychopharmacology Reports
July 20, 2025
Zofia Kachlik, Wiesław Jerzy Cubała, Michał Walaszek et al.
3 citations
Ketamine is a fast-acting antidepressant for treatment-resistant bipolar depression, but about 40% of patients do not respond. Among 35 patients receiving a four-week ketamine regimen, nonresponders had more psychiatric comorbidities (median 2 vs. 1) and were more likely to have any psychiatric comorbidity (78.6% vs. 33.3%) and prior benzodiazepine use (64.3% vs. 23.8%). Individual comorbidities and baseline suicidality were not linked to response. Ketamine remains safe and well-tolerated for short-term use, but a heavier comorbidity burden and benzodiazepine use may predict nonresponse.
Pharmacological reports : PR
April 30, 2025
Michał Walaszek, Wiesław Jerzy Cubała, Zofia Kachlik et al.
3 citations
Among inpatients with treatment-resistant depression receiving ketamine over four weeks, 75% did not respond. Non-responders had lower rates of prior substance use disorder (53.3% vs. 100%) and fewer psychiatric comorbidities. The findings suggest that a higher burden of traditional risk factors for treatment-resistant depression may not limit ketamine's effectiveness and could even enhance response compared to 'pure' major depressive disorder. Early identification of potential non-responders could optimize treatment decisions and reduce ineffective exposure.
Pharmacological reports : PR
December 1, 2024
Aleksander Kwaśny, Wiesław Jerzy Cubała, Adam Włodarczyk et al.
2 citations
In a small observational study of 28 inpatients with treatment-resistant major depressive disorder, neither those who responded to ketamine treatment nor those who did not reported significant changes in self-reported sleep problems—including insomnia, nighttime restlessness, early morning waking, or hypersomnia—after eight intravenous ketamine infusions over seven days. These results contrast with previous research that had suggested modest sleep improvements with ketamine. The authors caution that the small sample size limits the reliability of the findings.
Journal of affective disorders
August 15, 2026
Michał Walaszek, Wiesław Jerzy Cubała, Zofia Kachlik et al.
Anhedonia, a core symptom of major depressive disorder linked to poor outcomes, may be reduced by ketamine. In a retrospective analysis of 34 inpatients with treatment-resistant depression receiving short-term ketamine as an add-on to standard care, 16 patients (47.1%) did not respond to treatment, defined as less than a 50% reduction on the Snaith-Hamilton Pleasure Scale. Non-responders were more likely to be single, had fewer lifetime depressive episodes, and lower rates of prior substance use disorder. These factors suggest that psychosocial and demographic characteristics influence anhedonia treatment outcomes, supporting a personalized approach to mood disorder treatment.
Therapeutic advances in psychopharmacology
January 1, 2026
Zofia Kachlik, Wiesław Jerzy Cubała, Michał Walaszek et al.
Anhedonia, a core symptom of bipolar depression, often fails to improve with ketamine treatment in patients with treatment-resistant bipolar depression. In a retrospective analysis of 31 patients who received eight doses of ketamine, 45.2% did not achieve a 50% or greater reduction in anhedonia scores. Nonresponders tended to have higher body mass index, later illness onset, fewer hypomanic episodes, and lower employment rates. These metabolic, illness-course, and psychosocial factors may help predict which patients are less likely to benefit from ketamine's anti-anhedonic effects.