From the Guidelines
Effect of Cannabis on Brain Development
Cannabis use, particularly during critical periods of brain development, has been shown to alter the structure and function of the brain, particularly in regions responsible for attention, memory, and decision-making 1. Chronic use of tetrahydrocannabinol (THC), the primary psychoactive component of marijuana, has been associated with significant reductions in hippocampal volume and cortical thickness. Furthermore, adolescent exposure to THC, specifically during the period of rapid brain maturation between ages 13-18, may lead to persistent cognitive and behavioral deficits, including impaired executive function and increased risk of psychiatric disorders 1.
Key Findings
- Cannabis use during adolescence contributes to structural and functional changes in the brain, including altered grey matter volume and cortical thickness 1.
- Adolescent exposure to THC is associated with deficits in episodic memory, decision making, attention, and processing speed 1.
- Cannabis use during adolescence may increase the risk of psychopathology, including schizophrenia and psychosis 1.
- The effects of cannabis on brain development are more rapid among adolescents than adults, and many cannabis-related structural changes are unique to this age group 1.
Implications
The evidence suggests that cannabis use, particularly during adolescence, can have long-term consequences for brain development and function. Therefore, it is essential to exercise caution and consider the potential risks when using cannabis, especially during critical periods of brain development. Healthcare providers should be aware of the potential effects of cannabis on adolescent brain development and provide guidance and support to individuals who may be at risk 1.
From the Research
Effects of Cannabis on Brain Development
- The adolescent brain is particularly vulnerable to the effects of cannabis due to its ongoing development, with unique cognitive, emotional, and social changes occurring during this period 2, 3, 4.
- The endocannabinoid system plays a crucial role in brain development, and exposure to cannabis during adolescence can alter brain maturation and lead to long-lasting neurobiological changes 2, 5, 4.
- Chronic cannabis exposure during adolescence has been linked to impaired cognition, increased risk of substance abuse, and heightened risk of psychosis or schizophrenia in individuals with a predisposition 2, 3, 6.
Cognitive and Psychiatric Outcomes
- Emerging evidence suggests that early-onset marijuana use has long-lasting consequences on cognition, with a two-fold increase in the risk of developing a psychotic disorder 2.
- Adolescent cannabis exposure has been associated with persistent, adverse neuropsychiatric outcomes in adulthood, including impaired cognitive and psychiatric outcomes 5.
- The severity of the effects of cannabis use on cognitive development is dependent on the age when cannabis use begins, with earlier use increasing the risk of adverse outcomes 3, 6.
Brain Structure and Function
- Cannabis use during adolescence has been linked to alterations in brain structure and function, including changes in the prefrontal cortex (PFC) and medial prefrontal cortex (mPFC) 6, 4.
- These changes may underlie the development of adverse mental health conditions, including increased risk of substance abuse and psychosis 2, 3, 4.
- Preclinical evidence suggests that disruption from cannabis use is specific to the developmental period, with adolescent-onset exposure leading to persistent functional deficits in adulthood 5, 6.