Lithium Treatment and Suicide Risk in Major Affective Disorders: Update and New Findings

Background: Evidence that therapeutic benefits of psychiatric treatments include reduction of suiciderisk is remarkably limited and poorly studied. An exception is growing evidence for such suicidalrisk reduction with long-term lithium maintenance. This report updates and extends analyses of lithiumtreatment and suicides and attempts. Method: We pooled data from studies providing data on suicidalacts, patients at risk, and average exposure times with or without lithium maintenance therapy,and considered effects of lithium on selected subgroups. Results: Data from 34 reported studiesinvolved 42 groups with lithium maintenance averaging 3.36 years, and 25 groups without lithiumfollowed for 5.88 years, representing 16,221 patients in a total experience of 64,233 person-years.Risks for all suicidal acts/100 person-years averaged 3.10 without lithium versus 0.210 during treatment(93% difference) versus approximately 0.315 for the general population. For attempts, correspondingrates were 4.65 versus 0.312 (93% difference), and for completed suicides, 0.942 versus0.174 (82% difference). Subjects with bipolar versus various recurrent major affective disordersshowed similar benefits (95% vs. 91% sparing of all suicidal acts). Risk reductions for unipolar depressive,bipolar II, and bipolar I cases ranked 100%, 82%, and 67%. Suicide risk without lithiumtended to increase from 1970 to 2002, with no loss of effectiveness of lithium treatment. Conclusion:The findings indicate major reductions of suicidal risks (attempts > suicides) with lithium maintenancetherapy in unipolar ≥ bipolar II ≥ bipolar I disorder, to overall levels close to general populationrates. These major benefits in syndromes mainly involving depression encourage evaluation of othertreatments aimed at reducing mortality in the depressive and mixed phases of bipolar disorder and inunipolar major depression.