Lithium in unipolar depression and the prevention of suicide

Unipolar depression is a severe recurrent illness with high lifetime morbid ity and premature mortality due to suicide, Numerous double-blind, placebo- controlled trials have shown that lithium is very effective at reducing rel apses when given as maintenance therapy. It is also very effective when giv en as maintenance therapy after electroconvulsive therapy. It can be given once a day at night, and controlled trials have shown a 12-hour plasma lith ium level between 0.5 and 0.7 mmol/L the most effective, with very slight s ide effects. Long-term studies of lithium maintenance therapy show a suicid e rate of 1.3 suicides per 1000 patient years. This is much lower than comp arative studies in longterm follow-up of untreated depression, which show a bout 5.5 suicides per 1000 patient years. Although it is neither feasible n or ethical to carry out double-blind studies on suicide reduction, the mass ive evidence showing a reduction in morbidity on lithium treatment suggests that systematic long-term lithium treatment of unipolar depression could c onsiderably lower the suicide rate.