Biogenic amine turnover and serum cholesterol in suicide attempt

The investigation of biological correlates of suicidal behavior is important in searching for possible changes in neuronal systems activity related to that behavior, so that pharmacological interventions may be proposed, especially in high-risk subjects. In a sample of 111 subjects admitted in a general hospital after suicide attempt, we studied the turnover of neurotransmitters by measuring the urinary output of the main metabolites of serotonin, dopamine and noradrenaline (5-HIAA, HVA, MHPG respectively), as well as serum cholesterol, and compared them to those of a group of 62 healthy controls. Venous blood samples and urine samples were collected within 24 hours of admission. Psychiatric diagnosis was made according to DSM-IIIR criteria and assessment of suicide intent with Beck's Suicidal Intent Scale (SIS). Fifty-four (54) subjects received the diagnosis of adjustment disorder, 25 of depression, 16 of schizophrenia and 16 of personality disorder. Fourteen subjects (14) had employed a violent mode of attempt. Urinary MHPG was found significantly higher in all diagnostic groups compared to controls. No difference was found concerning the excretion of HVA and 5-HIAA. Serum total cholesterol was found significantly lower both in violent and non-violent attempters compared to controls after correcting for age. No difference in serum cholesterol or MHPG was found between violent and non-violent attempts. Serum cholesterol and MHPG correlated negatively, while the correlations between cholesterol and 5-HIAA or HVA were not significant. Our results confirm previous reports of lower serum cholesterol in attempted suicide. They are also indicative of an increased noradrenaline turnover in subjects who attempt suicide, at least within 24 hours after the attempt. Whether this activation precedes or follows the attempt because of the specific stress, can not be answered at present.