Lithium versus placebo in acute depression: a clinical trial

Thirty-one patients suffering from a major depressive illness were entered into a placebo-controlled double-blind study to determine the effectiveness of lithium carbonate in acute depression. Patients were allocated by minimization to receive either lithium or placebo for 6 weeks in 2 parallel groups without crossover. For ethical reasons patients who showed no satisfactory response could be withdrawn at the discretion of the investigator but this was done without breaking the treatment code. More patients were withdrawn from the placebo group than from the lithium group as treatment failures, but in spite of this there was a significant difference in the depression ratings between the 2 groups at weeks 4 and 5 in favour of the active treatment group (p less than 0.04 and p less than 0.03 respectively).