Relationship Between the Effectiveness of Lithium Therapy and Family History

As part of a continuing study, 72 manic-depressive patients were randomly assigned to treatment with either lithium carbonate or placebo. Of these, 67 percent were treated successfully and 33 percent were long-term failures. Data that reflected the incidence of psychopathology in the first- and second-degree relatives of the patients were collected. Striking differences were observed in the backgrounds of lithium responders and failures: response to lithium treatment was significantly associated with the presence of manic-depressive illness in the patients' families.