engleski

Suicidity and platelet serotonin concentration in alcoholism

Alcoholism has become a serious and global health problem, a chronic disease refractory to treatment, associated with high comorbidity, and frequently with suicidal behavior. Suicide is a major complication of different psychiatric disorders including alcoholism. Suicidal behaviour carries devastating effects on patients and their families, and financial burden on the whole society. The neurobiological basis of alcoholism, or suicidal behavior, involves the altered functions of different neurotransmitter systems including serotonin (5-hydroxytryptamine, 5-HT). Blood platelets might be used as limited peripheral model for the central 5-HT neurons, since platelets and 5-HT synaptosomes share similarities (in uptake, storage and release of 5-HT, in platelet monoamine oxidase (MAO) type B, 5-HT transporters, 5-HT2 and α 2-adrenergic receptors, and binding sites for 3H-imipramine, 3H-paroxetine, and 3H-LSD), and differences are in the synthesis and function of 5-HT. Platelet 5-HT concentration was reported to be decreased or unchanged in alcoholic patients, and reduced platelet 5-HT concentration has been found in suicidal behaviour in different psychiatric disorders. The hypothesis of this study was that alcoholic patients with suicidal behavior will have altered platelet 5-HT concentration when compared to non-suicidal alcoholics. Since we have previously shown that comorbid depression affected platelet 5-HT concentration in female alcoholic patients, alcoholic patients were subdivided into those with and without comorbid depression. Platelet 5-HT concentration was determined fluorimetrically in medication-free 252 male and 62 female ethnically homogenous medication-free subjects with alcoholism (diagnosis made using SCID based on the DSM-IV criteria), subdivided further according to the past history of suicidal attempts into suicidal and non-suicidal patients, and subdivided into those with or without comorbid depression, and these values were compared with platelet 5-HT concentration in corresponding subjects (control healthy subjects and depressed patients). Platelet 5-HT concentration was significantly lower in 252 male and 62 female alcoholic patients than in corresponding 147 male and 140 female control subjects. Sex differences in platelet 5-HT concentration were found, showing significantly lower values in female compared to male (control or alcoholic) subjects. Suicidality did not affect significantly platelet 5-HT concentration within male alcoholics, while female suicidal alcoholics had significantly higher platelet 5-HT concentration than nonsuicidal alcoholic women. Both suicidal male or female alcoholics had significantly lower platelet 5-HT concentrations than corresponding healthy subjects. Suicidal depressed patients had significantly lower platelet 5-HT concentration than the corresponding nonsuicidal depressed patients, or control subjects. The presence of comorbid depression in alcoholic patients did not affect platelet 5-HT concentration in male, but increased these values in female alcoholic patients. Platelet 5-HT concentration was reduced in all alcoholic patients. The presence of suicidal behaviour and/or comorbid depression increased platelet 5-HT concentration which was reduced in female alcoholic patients. In male alcoholic patients neither suicidality nor depression affected significantly platelet 5-HT values. The results from the present study did not confirm the hypothesis of a reduced platelet 5-HT concentration in suicidality across different psychiatric entities, indicating that a search for other valid peripheral biochemical marker(s) of suicidality must be continued for the screening or prediction of the suicidal risk in alcoholic patients.

platelet serotonin; suicidality; depression; alcoholism

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