Galantamine Effects on Cognitive Function in Marijuana Users

Overview

To evaluate galantamine's effects on cognitive performance in marijuana users. Galantamine, an acetylcholine esterase inhibitor, is approved for treatment of Alzheimer's disease. Current marijuana users show impaired cognitive functioning, which predicts poor treatment response to behavioral treatments in this population. Whether cognitive impairment in marijuana users will improve with medication treatment has not been evaluated. We hypothesize that galantamine, compared to placebo, will improve cognitive performance in marijuana users.Galantamine, compared to placebo, will improve working memory, verbal learning/memory and response inhibition functions in marijuana users.

To summarize, marijuana users show impaired cognitive functioning, especially in working memory and verbal learning and memory functions. Impaired cognitive functioning predicts poor treatment response in marijuana users. Whether the cognitive impairments in marijuana users improve with cholinergic enhancers has not been evaluated. In this double-blind, parallel-group study, we are proposing to evaluate galantamine's effects on cognitive performance in marijuana users. Thirty subjects will first have an adaptation session to familiarize them with the study procedures including cognitive assessment. The adaptation session will be followed by a 10-day treatment period, in which subjects will be randomized to galantamine (8 mg/day) or placebo. On Day 4 or 5 and Day 9 or10 of each treatment phase subjects will have test sessions, where a battery of cognitive tests will be administered. The cognitive test that will be administered will include the Hopkins Verbal Learning Test (HVLT) modules from the Cambridge Neuropsychological Test Automated Battery (CANTAB): the Rapid Visual Information Processing (RVIP) and the Stop Signal Test (SST). Currently this study is in data analysis with 30 completers. (April 2011)