While many people view marijuana as a benign, recreational drug, evidence exists of significant harm for some individuals who use it. 1 in 10 users develop cannabis dependence and sixteen percent of all substance abuse treatment admissions in the United States are for cannabis-related disorders; this is second only to alcohol-related disorders (1).
Some marijuana-related cognitive function deficits improve after stopping use of the drug, but growing evidence suggests there are long-term effects (2) that may hinder an individual’s ability to make the best use of behavioral therapies. Many factors can impact cannabis-related impairment and recovery of cognitive functions, including the age in which the user started smoking cannabis, years of use and the amount of regular use (3).
The Effects of Cannabis Use on Adolescents and Young Adults
As neuroimaging technology improves, reports are showing subtle, long-term effects of cannabis on cognition and brain functioning (2). Some studies suggest that regular marijuana use in adolescence is associated with altered connectivity and reduced volume of specific brain regions involved in memory, learning and impulse control (4, 5). One compelling study showed that those who started smoking between the ages of 14-22 years old and stopped by age 22 had significantly more cognitive problems at age 27 than their non-using peers (6). In addition to this, adult cannabis users who began smoking before age 17 had significant impairments in measures of executive functioning (7).
A number of studies have shown that abilities such as planning, inhibition and decision-making continue to develop into early adulthood (8). It is safe to say that marijuana use throughout adolescence and young adulthood may impair the achievement of developmental milestones in cognitive functioning. Cognitive impairment has been generally associated with poorer drug abuse treatment outcomes (9). Prevalence rates for cannabis use have increased in recent years (1), which means chronic, heavy cannabis use is a growing health concern.
Help for Cannabis Addiction
If you think that you or a loved might have a problem with cannabis, reach out for help from a therapist and a local Marijuana Anonymous (MA) group.
If the addiction is severe and is accompanied by other disorders such as depression, anxiety, or bipolar disorder—and it often is— inpatient or intensive outpatient treatment may be needed. If so, look for a program that provides treatments that can begin to heal both the emotional and neurological aspects of addiction through trauma work, experiential therapies like equine therapy and art therapy, and brain-based therapies like biofeedback and neurofeedback.
8. Romine CB, Reynolds CR. A model of the development of frontal lobe functioning: findings from a meta-analysis. Appl Neuropsychol 2005;12(4):190–201. [PubMed: 16422660]
9. Abbott MW, Gregson RA. Cognitive dysfunction in the prediction of relapse in alcoholics. J Stud Alcohol 1981;42(3):230–43. [PubMed: 7306259]