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 .
Psychomotor Function in Chronic Daily Cannabis Smokers during Sustained Abstinence
Background The present study assessed psychomotor function in chronic , daily cannabis smokers during 3 weeks continuously monitored abstinence on a secure research unit . We hypothesized that psychomotor performance would improve during abstinence of chronic , daily cannabis smokers . Methodology /Principal Findings Performance on the critical tracking ( CTT ) and divided attention ( DAT ) tasks was assessed in 19 male chronic , daily cannabis smokers at baseline and after 8 , 14–16 and 21–23 days of continuously monitored abstinence . Psychomotor performance was compared to a control group of non-intoxicated occasional drug users . Critical frequency ( λc ) of the CTT and tracking error and control losses of the DAT were the primary outcome measures . Results showed that chronic cannabis smokers ’ performance on the CTT ( p<0.001 ) and the DAT ( p<0.001 ) was impaired during baseline relative to the comparison group . Psychomotor performance in the chronic cannabis smokers improved over 3 weeks of abstinence , but did not recover to equivalent control group performance . Conclusions / Significance Sustained cannabis abstinence moderately improved critical tracking and divided attention performance in chronic , daily cannabis smokers , but impairment was still observable compared to controls after 3 weeks of abstinence . Between group differences , however , need to be interpreted with caution as chronic smokers and controls were not matched for education , social economic status , life style and race
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 .