NEW YORK, August 25 (Praxis Press). Early-onset alcoholism (before age 25 years) is associated with serotonergic dysfunction, and individuals with early-onset alcoholism may be responsive to treatment with a selective serotonergic agent. To compare the effectiveness of ondansetron, a selective serotonin receptor antagonist, in the treatment of early-onset and late-onset alcoholism, Johnson and colleagues performed a double blind, randomized, placebo-controlled clinical trial. A total of 321 patients with diagnosed alcoholism (mean age 40.6 years; 70.5% male; 78.6% white) were enrolled, 271 of whom were selected for the study. Patients were randomly assigned to receive 11 weeks of treatment with three different doses of ondansetron, (1, 4, and 16 micrograms/kg twice per day), or a placebo (n = 56). All patients also participated in weekly sessions of standardized group cognitive-behavioral therapy. The researchers found that participants with early-onset alcoholism who received ondansetron consumed fewer drinks per day and...