An open-label pilot study of risperidone in the treatment of methamphetamine dependence

Psychopharmacological treatments for methamphetamine (MA) dependence have questionable efficacy. Open-label risperidone was evaluated in veterans seeking MA dependence treatment. Participants (N = 11) received four weeks of risperidone. They provided weekly self-reports of substance use, urine drug screens, and adverse effects. Neuropsychological assessments and psychiatric symptomatology (Brief Symptom Inventory; BSI) were measured at baseline and follow-up. The eight completers had an average risperidone dose of 3.6 mg/day and decreased days of MA use during the trial from a mean of 13.0 (SD = 6.5) in the 30 days prior to starting risperidone to a mean of 0.125 (SD = 0.4; t = 5.7, p = .001), When measured over time, fine motor function (Grooved Peg Board Dominant Hand) was the only neuropsychological domain to improve significantly. No other domain changed significantly from baseline to follow-up among study completers. BSI data were converted to demographically corrected T-scores utilizing appropriate normative data (mean = 50, SD = 10). BSI somatization T-scores declined from a mean of 59.0 (SD = 8.4) to 51.8 (SD = 8.3; t = 2.7, p <.05), and positive symptom distress declined from a mean of 52.8 (SD =8.0) to 41.7 (SD = 8.6; t= 3.0, p <.05). Risperidone was well tolerated and associated with decreased MA use.