New Study Reveals Acute Effects of Cannabis on Brain Connectivity in Adolescents and Young Adults
Article Written by Adam Isaac Miller
A recent study published in The Journal of Neuropsychopharmacology has documented the acute effects of different types of cannabis on brain connectivity in adolescents and young adults. The study, led by researchers at the University of Bath and University College London, used functional magnetic resonance imaging (fMRI) to investigate how THC and CBD, two main components of cannabis, influence resting-state brain networks.
The study included 46 participants, consisting of 22 adolescents (aged 16-17) and 24 young adults (aged 26-29) who were semi-regular cannabis users. Participants underwent three treatment sessions: placebo, 'THC' (8 mg/75 kg), and 'THC + CBD' (8 mg/75 kg THC & 24 mg/75 kg CBD). The study employed a placebo-controlled, randomized, double-blind design to ensure robust results.
Key Findings
Reduced within-network connectivity: Acute cannabis administration, both with THC alone and THC + CBD, reduced connectivity within several resting-state networks compared to placebo. These networks include the default mode network (involved in self-referential thought and memory), executive control network (involved in cognitive control and decision-making), salience network (involved in detecting and integrating relevant stimuli), hippocampal network (involved in memory formation and retrieval), and limbic striatal network (involved in emotion and motivation).
Disrupted whole-brain functional connectivity: Cannabis disrupted functional connectivity between various cortical regions and the resting-state networks, suggesting widespread effects on brain connectivity.
CBD did not counteract THC's effects: Contrary to the hypothesis, CBD did not reduce THC's effects on brain connectivity. The 'THC + CBD' condition further reduced connectivity both within networks and across the whole brain compared to THC alone.
No age-related interactions with cannabis treatment: While some age-related differences in brain connectivity were observed, there were no significant interactions between age group (adolescents vs. young adults) and cannabis treatment in any of the investigated brain networks.
Implications
The findings of this study have important implications for our understanding of the acute effects of cannabis on brain function and public health:
Disruption of cognitive and emotional processes: Reduced within-network connectivity and disrupted whole-brain functional connectivity suggest that acute cannabis exposure may alter normal functioning and communication within brain systems involved in cognitive processes, emotional regulation, and memory formation. This may help explain some of the cognitive and behavioural changes observed in cannabis users.
Challenging the notion of CBD as a safeguard: The finding that CBD did not counteract THC's effects and even potentiated them challenges the common assumption that CBD can mitigate the negative effects of THC and make cannabis safer. This has important implications for public health messaging and harm reduction strategies, as cannabis products containing high CBD:THC ratios may not necessarily be safer for users.
Similar acute effects in adolescents and young adults: The lack of significant interactions between age groups and cannabis treatment suggests that adolescents and young adults may be similarly affected by acute cannabis exposure, at least in terms of the studied resting-state networks. However, further research is needed to understand the long-term consequences of cannabis use, particularly during the critical period of adolescent brain development.
This study provides valuable insights into the acute effects of cannabis on brain connectivity, challenging common assumptions about the role of CBD and the differential vulnerability of adolescents to cannabis use. The findings underscore the need for further research to understand better the complex interactions between THC and CBD and their impact on brain function, as well as the long-term consequences of cannabis use. The results also highlight the importance of evidence-based public health messaging and harm reduction strategies to promote informed decision-making regarding cannabis use.
Adam has spent over eight years working with unregistered medicines. With a specialization in Cannabinoid Therapeutics, Adam has supported the development, implementation, and market entry of multiple cannabinoid product portfolios in markets such as Australia, New Zealand, Germany, and Brazil. Before working in the medical cannabis field, Adam spent almost a decade building various B2B businesses within education, investment, and medicinal cannabis, with progressive roles including business development, strategy, product development, and project management. He has consulted private and listed cannabis producers and ancillary businesses since 2015 as one of the early entrants and experts in the burgeoning Australian cannabis industry. Adam founded and sat on the board of The Medical Cannabis Council, Australia’s first not-for-profit industry body. He is a frequent public speaker and publishes a widely read industry newsletter. Adam earned a Bachelor of Entrepreneurship from the Royal Melbourne Institute of Technology. Adam has appeared in several major news outlets, including the Sydney Morning Herald, The Australian Financial Review, Nine News, Startup Smart, SBS, SkyNews, MJBizDaily, and other major publications.
Disclaimer: This information is shared with a global readership for educational purposes only and does not constitute medical or business advice. All patient-related information has been de-identified OR fictional to protect privacy. Nothing in this article is intended to promote the use or supply of medical cannabis to members of the public.