Improved neurocognitive functioning after cannabis abstinence

In the enthusiastic rush to embrace recreational and medicinal cannabis, it is possible that some factors associated with use of the drug are not receiving the attention they might.  Adolescent cannabis use has been reported to be associated with compromised neurocognitive functioning. In a study recently published in the Journal of Clinical Psychiatry, researchers systematically assessed 88 adolescents and young adults (aged 16–25 years) who used cannabis regularly, randomly assigning the subjects to 4 weeks of cannabis abstinence (verified by measurement of THC urine concentration) or a monitoring control condition with no abstinence requirement. Attention and memory were assessed at baseline and weekly for 4 weeks with the Cambridge Neuropsychological Test Automated Battery. 55 (88.7%) met the criteria for biochemically confirmed 30-day continuous abstinence. Abstinent participants had better memory overall and at weeks 1, 2, 3 but no effect of abstinence on attention. The researchers conclude that cannabis abstinence is associated with improvements in verbal learning that appear to occur largely in the first week following last use. Another aspect that warrants consideration in the overall picture, albeit the extent of cannabis exposure does not appear to be quantified in the study reported here.