Effectiveness of lithium in schizophrenia: do we really have an answer?

The authors review all double-blind studies assessing the efficacy of lithium treatment in schizophrenia. They conclude that active affective symptoms, previous affective episodes, and a family history of affective disorder may predict a favorable response to lithium. However, methodological problems in past studies (e.g., small samples, lack of strict diagnostic criteria) suggest that further clinical trials are warranted.