Platelet imipramine binding in intensive care unit suicidal patients.

3H-Imipramine binding in relation to serotonergic function was studied in patients hospitalized following a suicide attempt. Comparison with a control group showed a highly significant difference in Bmax values. The results suggest, at least a posteriori, a biological alteration as the basis of suicidal behaviour. Although it is impossible to attribute a suicidal attempt to the alteration or to a predisposing pre-existent condition, this biological marker may be useful in evaluating suicidal risk and also short- and long-term prognosis.