Factors influencing monoamine metabolites and tryptophan in patients with alcohol dependence.

Cerebrospinal fluid 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA) and tryptophan (TRY) were measured in 36 female patients with alcohol dependence defined by strict operational criteria. Results were compared with a control group of 32 women hospitalized in a neurological unit for peripheral diseases. Several disorders presumably interfering with monoamine metabolism were excluded and diet, psychomotor activity, diurnal variation, nutritional state and similar nonspecific variables controlled in both groups. Only 5-HIAA was found to be decreased in development patients as compared to controls. Since 5-HIAA--but neither HVA nor TRY--correlated with body height in both groups, we eliminated its effect by analysis of covariance: as a result 5-HIAA difference became statistically significant but the other two biochemical measures remained unchanged. A multivariate regression analysis with five independent clinical variables (body height, age, weight, years of alcohol abuse and days of abstinence) yielded significant determination coefficient R2 only for 5-HIAA. Regarding its components only body height and days of abstinence proved to be significantly correlated with 5-HIAA. Severity of withdrawal symptoms assessed on a rating scale in 14 patients with 4 days or less of abstinence correlated marginally with HVA but not with 5-HIAA. This latter metabolite decreased only in patients with 5 days or more of abstinence; the difference between 5-HIAA levels of short-term and long-term abstinence subgroups was statistically highly significant.