Prefrontal cortical thinning associated with increased cannabis use in adolescence

Increased cannabis use during adolescence was associated with altered neural development, according to the results of a 5-year follow-up from a community-based cohort. The results of a study on the subject were published in JAMA Psychiatry.

The IMAGEN study recruited participants (n = 799) aged 14 years in 8 European cities between 2008 and 2011 for 5 years of follow-up. At the start of the study and in the follow-up, the subjects were examined for substance use and impulsiveness and subjected to magnetic resonance imaging (MRI). A separate group of men aged 18 to 35 years (n = 21) underwent positron emission tomography (PET) scans to map the availability of cannabinoid 1 (CB1) receptors.

The study population consisted of 56.3% girls with an average age of 14.4 (standard deviation [SD], 0.4) years at the start of the study, the verbal intelligence quotient was 112.6 (SD 13.0) and the achievement intelligence quotient 109.6 (SD 13.6).

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At follow-up, 208 people reported having used cannabis on 1-9 occasions and 161 reported having used it 10-> 40 times.

Lifelong cannabis use was associated with the left prefrontal cortex (t[785], -4.87; P = 1.10 × 10–6) and right prefrontal cortex (t[785], -4.27; P = 2.81 × 10-5) thicknesses.

A significant time was observed for age-related cortical thinning in the left prefrontal cortex due to cannabis interaction (t[815.27], -4.24; P = 2.28 × 10–8) and right prefrontal cortex (t[813.30], -4.71; P = 3.72 x 10-8). This interaction indicated that greater cannabis use between baseline and follow-up was associated with cortical thinning.

The areas showing increased availability of the CB1 receptor were negatively correlated with the cortical thickness (r, -0.189; P <0.001). The pattern of cannabis-related thinning correlated positively with age-related thinning (r, 0.540; P <0.001).

An association between impulsivity after 5 years and cannabis-related cortical thinning of the right dorsomedial prefrontal cortex (b, -0.119; P = 0.003) after correction of potential covariates was observed.

This study was limited because it did not have access to PET scans in the same people who had MRIs and longitudinal assessments of cannabis use. The young person’s reactions may have been distorted by social norms.

This study identified an association between cannabis use during adolescence and thinning of the left and right prefrontal cortexes. According to the researchers, “the results underscore the importance of further longitudinal studies of cannabis use among adolescents, particularly given the increasing trends in the legalization of recreational cannabis use”.

Disclosure: Several authors stated links to industry. For a full list of the details, see the original article.


Albaugh MD, Ottino-Gonzalez J, Sidwell A, et al. Relationship of cannabis use in adolescence to the development of the nervous system. JAMA psychiatry. Published online June 16, 2021. doi: 10.1001 / jamapsychiatry.2021.1258

This article originally appeared on Psychiatry Advisor

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