RESULTS Although causality is unclear , heavy and dependent cannabis use is consistently associated with a high prevalence of comorbid psychiatric disorders and learning and memory impairments that seem to recover after a period of abstinence .
Evidence regarding other cognitive domains and neurological consequences including cerebrovascular events is limited and inconsistent .
Abstinence after treatment is only achieved in a minority of cases ; treatment targeted at reduction in use appears have some success .
Potential moderators of the impact of CUD on the brain include age of onset , heaviness of use , CUD severity , the ratio of ∆9-tetrahydrocannabinol to cannabidiol , and severity of comorbid disorders .
Current evidence of long-term effects of daily cannabis use and cannabis use disorder on brain-related outcomes is suggestive rather than conclusive but use is associated with psychiatric morbidity and with cognitive impairments that recover after a period of abstinence
AIMS To summarize and evaluate our knowledge of the relationship between heavy cannabis use , Cannabis Use Disorder ( CUD ) , and the brain .
Acute effects of smoked marijuana on decision making, as assessed by a modified gambling task, in experienced marijuana users
The impact of regular marijuana use on executive cognitive abilities , including decision making , is not well understood . While cross-sectional studies have suggested that substance abusers exhibit impaired decision making , as assessed by the Iowa Gambling Task , the direct role of marijuana use in the Gambling Task performance of marijuana smokers has not been well defined . In this report , we present data on performance on a modified Gambling Task  in experienced marijuana users after they had smoked marijuana under controlled laboratory conditions . A total of 36 marijuana users , who reported smoking approximately 24 marijuana cigarettes per week , completed this 3-session outpatient study . During each session , these volunteers completed the Gambling Task once at baseline and 3 times after smoking a single marijuana cigarette ( 0.0 , 1.8 , or 3.9 % Δ9-THC ) . Marijuana cigarettes were administered in a double-blind fashion , and the sequence of Δ9-THC concentration was balanced across volunteers . Marijuana increased the time required to complete the task . However , advantageous card selection and money earned on the task were not disrupted by marijuana . These data are consistent with previous findings that indicated that speed of performance on tests of executive function , but not accuracy , is disrupted in experienced marijuana users during marijuana intoxication
RESULTS Although causality is unclear , heavy and dependent cannabis use is consistently associated with a high prevalence of comorbid psychiatric disorders and learning and memory impairments that seem to recover after a period of abstinence .
Evidence regarding other cognitive domains and neurological consequences including cerebrovascular events is limited and inconsistent .
Abstinence after treatment is only achieved in a minority of cases ; treatment targeted at reduction in use appears have some success .
Potential moderators of the impact of CUD on the brain include age of onset , heaviness of use , CUD severity , the ratio of ∆9-tetrahydrocannabinol to cannabidiol , and severity of comorbid disorders .
Current evidence of long-term effects of daily cannabis use and cannabis use disorder on brain-related outcomes is suggestive rather than conclusive but use is associated with psychiatric morbidity and with cognitive impairments that recover after a period of abstinence
AIMS To summarize and evaluate our knowledge of the relationship between heavy cannabis use , Cannabis Use Disorder ( CUD ) , and the brain .