-Methamphetamine (MA) use is growing to epidemic proportions and existing treatments for MA dependence demonstrate sub-optimal efficacy. Research implicates heavy use of MA as at least a contributing agent to a variety of neuropsychiatric impairments including psychosis, mood disturbance, anxiety, cognitive deficits, and motor dysfunction. Initial study by this investigator suggests that agents like risperidone may also be beneficial to MA dependent individuals by decreasing MA use and improving cognitive function in early abstinence. Long-acting injectable risperidone may prove more efficacious given its receptor binding characteristics and potential to increase medication adherence. The study objective is to determine the safety and efficacy of treating MA dependence and the associated cognitive and psychiatric symptomatology with long-acting injectable risperidone.