Treatment of alcohol dependence in patients with co-morbid major depressive disorder – predictors for the outcomes with memantine and escitalopram medication

BACKGROUND: Alcohol dependence comorbid with major depressive disorder poses a major challenge in the clinical setting. The results in the treatment with selective serotonin re-uptake inhibitors have been conflicting. Thus, we compared in alcohol-dependent patients with co-morbid major depressive disorder the selective serotonin re-uptake inhibitor escitalopram to a compound that acts on different transporter system and may reduce craving, the glutamate receptor antagonist memantine. METHODS: Eighty alcohol-dependent patients comorbid with major depressive disorder in municipal alcohol clinics were randomized 1:1 to receive memantine 20 mg or escitalopram 20 mg in a double-blind manner. During the 26-week study period patients continued their routine treatment at the clinics. Abstinence was not required but encouraged. The patients attended visits weekly during the first month, and then at 3 and at 6 months. Outcome measures were Alcohol Use Disorders Identification Test (AUDIT), Obsessive Compulsive Drinking Scale (OCDS) and Drinking Diary. RESULTS: The completion rate was high in both groups, especially among the patients who had been abstinent at the beginning of the study. However, among those patients who were not abstinent at baseline, 47% in both groups discontinued the study. Numbers of abstinent days were high in both groups throughout the study. Alcohol consumption measured by the AUDIT QF (quantity-frequency) score was significantly reduced in both groups, as was the craving for alcohol measured by the OCDS. Early age at first alcohol intoxication predicted poor treatment outcomes in patients treated with escitalopram, and the same was seen with the early onset of the first depressive episode. The same predictive effects were not found in patients treated with memantine. CONCLUSION: Our results indicate that both memantine and escitalopram are useful adjunct medications for the treatment of alcohol dependence co-morbid with major depression. Memantine was at least as effective with regard to drinking as escitalopram. We believe that a direct comparison of memantine, with the commonly used escitalopram, can provide useful information for clinicians on the treatment of alcohol dependency co-morbid with MDD. TRIAL REGISTRATION: ClinicalTrials.gov Identifier # NCT00368862