Marijuana Neuropsychological

Culver CM, King FW. (1974). Neuropsychological assessment of undergraduate marijuana and LSD users. Arch Gen Psychiatry. 31 707-711. 

Recently, two studies have examined the residual effects of long-term marijuana use.224,225 In both studies, marijuana smokers were abstinent for 28 days during which time a battery of neuropsychological tests was repeatedly administered. Daily, chronic smokers were compared to less frequent smokers. Bolla et al.224 reported that daily smokers were impaired on tests of memory, executive functioning, and psychomotor skills after 28 days of marijuana abstinence. In contrast,... 

Pope et al.225 found neuropsychological impairment during the first week of abstinence, but by day 28, there were no differences between daily smokers and control subjects. Both studies found that daily smokers evidenced greater impairment than less frequent smokers, which is consistent with the dose-related effect noted above for acute marijuana studies. 

Lyons MJ, Bar JL, Panizzon MS, Toomey R, Eisen S, Xian H, Tsuang MT. Neuropsychological consequences of regular marijuana use a twin study. Psychol Med 2004 34(7) 1239-50. 

The methods described below in human marijuana users and respective nonmarijuana users outline (1) neuropsychological assessment of marijuana users, (2) transcranial doppler sonography, and (3) EEG recordings and analysis. 

Neuropsychological procedures are used in an effort to provide an unbiased estimate of the individual s cognitive capacity. In neurology and psychiatry, these tests have been used to help clinicians to better diagnose patients and to provide them with better treatments. We chose to use a fixed battery in our effort to assess neurobehavioral changes that might be associated with the chronic use of marijuana. That battery included tests of language skills, visual and spatial memory, attention, concentration, executive function, visuo-constructive skills, manual dexterity, simple reaction time, and complex reaction time in subjects in our studies. The various tests used are listed below. 

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