Suicidal Behavior in Depression: Relationship to Platelet Serotonin Transporter

OBJECTIVE: Suicidal behavior in depressed patients is associated with low central serotonin. Thus, platelet serotonin uptake in relation to suicidal behavior in depression was examined. METHODS: Depressed patients who had never attempted suicide (n = 23) were compared with depressed patients who had never attempted suicide (n = 26) and normal controls (n = 71) for platelet serotonin uptake. RESULTS: Depressed patients who had a lifetime history of a suicide attempt had a significantly greater apparent Michaelis constant (Km) of platelet serotonin uptake than either depressed patients who had never attempted suicide or controls. Patients rated high for current suicidal ideation at the index admission had significantly higher Km values than patients rated low. Also, patients who reattempted or committed suicide during a 5-year follow-up period had significantly higher Km values than controls. Among women patients who had attempted suicide there was a significant correlation between extrapunitive hostility scores and Km values. CONCLUSION: The serotonin transporter warrants further study in relation to suicidal behavior in depression.