Trial of Ketamine and Lithium Therapy in Bipolar Depression

Randomised, quadruple-blind, Phase II crossover study evaluating the safety and efficacy of combined ketamine and lithium versus ketamine alone and placebo for treatment of bipolar depression.

Adults meeting DSM-IV criteria for bipolar disorder in a major depressive episode with MADRS ≥18 and QIDS-SR16 ≥19 were eligible; key exclusions included psychotic disorders, recent substance dependence, significant medical/neurological illness, positive urine drug screen, and high suicide risk.