New research suggests that long-term, heavy cannabis use is associated with subtle changes to the frontal cortex, the part of the brain involved in decision-making and executive function.
The study, the findings of which were presented at the 2026 European Congress of Psychiatry this month, focused specifically on adults with long-term, heavy use patterns.
Researchers conducted high-resolution magnetic resonance imaging scans in 46 adults, with an average age of 31, who had used cannabis for at least 10 years and consumed it daily for at least five years.
The group was compared with 46 adults who had used cannabis fewer than 10 times in their lifetime and matched for age, sex, and IQ, to examine whether measurable structural differences were present.
Cortical thickness refers to the width of the brain’s outer layer. Surface area and cortical volume are additional measures of brain structure that reflect overall size and shape.
The authors also examined the volume of subcortical nuclei deeper in the brain, in areas involved in movement and memory.
Key findings
Two areas of reduced cortical thickness were identified in the right rostral middle frontal cortex in long-term heavy cannabis users
After controlling for potential confounders by adjusting for standard drink units and excluding recent, sporadic cocaine users, the reduction in right rostral middle frontal cortical thickness remained significant, although only one cluster was observed.
This region forms part of the prefrontal cortex, which plays a central role in executive functions such as planning, working memory, and impulse control
No significant differences were observed between users and non-users in overall cortical volume or in cortical surface area.
Implications for public health
The findings suggest that long-term heavy cannabis use may be linked to subtle and region-specific cortical thinning, rather than widespread changes, the authors say, although the study does not establish ‘cause and effect’.
Aquino-Servin, Lead Author, FIDMAG Germanes Hospitalàries Research Foundation, said: “We found reduced thickness in a frontal brain region that supports executive functioning. While this study does not establish cause and effect, it adds to growing evidence that sustained heavy cannabis use may be associated with structural brain differences.”
Dr. Julian Beezhold, the Secretary General of the European Psychiatric Association, added: “As cannabis policies and public attitudes evolve, robust imaging studies like this are important for informing public health discussions with objective data.”
The post Long-Term Heavy Cannabis Use Linked to Subtle Changes in Brain Structure appeared first on Cannabis Health News.
Go to Source
Author: News Editor
