Sherwood Brown and colleagues from the University of Texas Southwestern Medical Center have completed a successful placebo-controlled trial of citicoline for bipolar and unipolar depression with comorbid methamphetamine dependence. Forty-eight participants with methamphetamine dependence and either unipolar or bipolar depression were randomized to either citicoline (2000 mg/day) or placebo for 12 weeks. Those receiving citicoline had significantly greater improvement in scores on the Inventory of Depressive Symptoms compared with those who received placebo, and patients receiving citicoline stayed in the study significantly longer, with completion rates of 41% on citicoline and 15% on placebo.

In 2007, the same team of investigators reported in the Journal of Clinical Psychopharmacology that citicoline had positive effects in bipolar patients with cocaine dependence, who experienced significant decreases in cocaine use and fewer cocaine-positive urine tests while taking citicoline.