Neurophysiological functioning of occasional and heavy cannabis users during THC intoxication
Psychopharmacology October 5, 2011 Eef L. Theunissen, Gerold F. Kauert, Stefan W. Toennes et al. 82 citations
Heavy cannabis users develop tolerance to some impairing effects of cannabis, observable both in behavior and in brain electrical activity. In a double-blind, placebo-controlled crossover study, 12 occasional and 12 heavy cannabis users smoked a joint containing either 0 or 500 μg/kg body weight THC. During a divided attention task, THC reduced P100 amplitude in occasional users but not in heavy users, indicating tolerance at the neural level. P300 amplitude decreased in both groups. Performance on the stop signal task was impaired in both groups after THC, while divided attention task performance was impaired only in occasional users. Tolerance was evident in event-related potentials, suggesting it is not solely due to behavioral compensation.