Lithium Therapy and Suicide Risk

Background: Studies from the early 90s have suggested that patients selected for and compliant with treatment at specialized lithium clinics have lower-than-expected suicide rates. The present studyexamines whether such findings can be replicated under less select treatment conditions. Method: All 362 patients in Göteborg, Sweden, with DSM-III-R mood or schizoaffective disorders, hospitalized atleast once during an 8-year period and treated with lithium for a minimum of 1 year, were followed.The study included 3911 patient-years on lithium and, because of permanent or temporary discontinuation,1274 patient-years off lithium. Results: The risk of suicide was significantly increased on (standard mortality ratio [SMR] = 6.1) as well as off lithium (SMR = 29.0), but the relative risk of suicidewas 4.8 times higher during periods off lithium (p < .02; 95% confidence limits 1.1 to 12.6). Ongoinglithium treatment was associated with a 77% reduction in the risk of suicide, whereas alcohol or drugabuse was associated with a 284% increased risk. Conclusion: The findings suggest that ongoing lithium treatment is associated with a lower suicide risk. Whether this is due to lithium’s mood-stabilizingproperties, to lower suicide risk per se in the patients who remain in treatment, or to a specificantisuicidal effect of the lithium ion cannot be determined since patients were not randomized to discontinuetreatment. This methodological shortcoming is shared with every study in the field. All resultsregarding the influence of lithium on suicide rates must therefore be interpreted with extremecaution.