THURSDAY, Nov. 8, 2018 (HealthDay News) -- Abstaining from cannabis is associated with improvements in memory and verbal learning in adolescents and young adults, according to a study published online Oct. 30 in the Journal of Clinical Psychiatry.
Randi Melissa Schuster, Ph.D., from Massachusetts General Hospital in Boston, and colleagues randomly assigned 88 adolescents and young adults (aged 16 to 25 years) who used cannabis regularly to either four weeks of cannabis abstinence, verified by decreasing 11-nor-9-carboxy-∆9-tetrahydrocannabinol urine concentration (MJ-Abst; 62 participants), or a monitoring control condition with no abstinence requirement (MJ-Mon; 26 participants). At baseline and each week for four weeks, attention and memory were assessed with the Cambridge Neuropsychological Test Automated Battery.
The researchers note that 88.7 percent of MJ-Abst participants met a priori criteria for biochemically confirmed 30-day continuous abstinence. Abstinence had an effect on verbal memory (P = 0.002) that was consistent across four weeks of abstinence and was driven by improved verbal learning in the first week of abstinence. At weeks one, two, and three, MJ-Abst participants had better memory overall than MJ-Mon participants. Only MJ-Abst participants improved in memory from baseline to week one. Both groups improved similarly for attention, consistent with a practice effect.
"The good news part of the story is that at least some of the deficits associated with cannabis use are not permanent and actually improve pretty quickly after cannabis use stops," Schuster said in a statement.