Ketamine for unipolar depression: A systematic review of efficacy and safety

BackgroundUnipolar depression is a prevalent mental health disorder with persistent, treatment-resistant symptoms. Traditional antidepressants take weeks to show effects, underscoring the need for faster alternatives. Ketamine, originally an anaesthetic, has emerged as a rapid-acting antidepressant.ObjectiveThis systematic review evaluates ketamine's efficacy and safety in unipolar depression.MethodsA literature search (January 2000-May 2024) in PubMed, PsycINFO, and Cochrane Library included RCTs, CCTs, systematic reviews, meta-analyses, and observational studies on ketamine or esketamine in formally diagnosed individuals. Study characteristics, interventions, outcomes, and adverse events were analyzed, with quality and bias assessments.ResultsAcross 44 studies, ketamine significantly reduced depressive symptoms and suicidal ideation within hours, particularly in treatment-resistant cases, with effects lasting up to 1 week. Common side effects included transient dissociation, elevated blood pressure, nausea, and dizziness, while long-term safety remains uncertain.ConclusionsKetamine shows promise as a rapid antidepressant for treatment-resistant unipolar depression. However, long-term safety and optimal treatment protocols require further research. Careful clinical integration with monitoring is recommended.