Few studies have been performed in patients with a dual diagnosis of depression and alcohol dependence. Most data have been gathered at detoxification centers, where rates of depression would be expected to be lower than those in patients of psychiatric hospitals. Patients with alcohol dependence and depression have been noted to have symptoms associated with a low serotonergic state, including suicidal tendency and impulsivity, and low cerebrospinal fluid levels of 5-hydroxyin-doleacetic acid, the major metabolite of serotonin. Cornelius and associates studied the ability of fluoxetine, a selective serotonin reuptake inhibitor, to reduce depressive symptoms and alcohol consumption in alcoholic patients with depression.
The 51 patients included in the study met the criteria for both major depressive disorder and alcohol dependence. Patients were randomly assigned to receive fluoxetine, 20 mg daily initially, or placebo. The daily fluoxetine dosage was increased to 40 mg after two weeks if substantial depressive symptoms persisted. Compliance was monitored by weekly pill counts and plasma drug levels obtained at weeks 2, 4 and 12. Patients were seen weekly for routine psychiatric care, which included psychotherapy sessions with the same psychiatrist. In addition, weekly ratings of depression and alcohol use were obtained throughout the 12-week study.
No significant differences were apparent between the two groups in age, sex, race, and marital and employment status. The percentage of patients who had made a suicide attempt during the current depressive episode did not differ in the two groups.
At the end of 12 weeks, the fluoxetine group showed a significant decrease in depression based on the Hamilton Rating Scale for Depression (HAM-D) and the Global Assessment Scale (GAS). Improvement in the GAS was three times greater in the fluoxetine group than in the placebo group.
Total alcohol consumption was three times greater in the placebo group than in the fluoxetine group. Both the cumulative number of drinking days and the number of drinks per day were significantly higher in the placebo group. Also, no significant correlation was noted in the fluoxetine group between the level of drinking and the level of depression at baseline, six weeks and 12 weeks.
The authors conclude that fluoxetine is effective in treating depressive symptoms as well as reducing alcohol consumption in patients with these comorbid illnesses. Moreover, the findings suggest that the antidrinking effect of fluoxetine is not entirely due to its antidepressant effect. However, the pharmacology of fluoxetine's antidrinking effect remains to be determined. Larger trials of selective serotonergic agents in depressed alcoholic patients are recommended.