Adolescents and adults showed different brain reward responses to cannabis in a controlled fMRI experiment
In a placebo-controlled crossover trial, acute THC blunted reward-related brain activity in adults but not adolescents, and adding CBD partially offset that effect.
Quick Facts
What This Study Found
Adults showed reduced ventral striatum activation during reward anticipation after THC, while adolescents did not. The THC+CBD condition partially attenuated this blunting in adults, suggesting CBD may modulate THC effects on reward circuitry.
Key Numbers
47 participants (24 adolescents, 23 adults). THC dose: 0.107 mg/kg (about 8 mg for 75 kg person). CBD dose: 0.320 mg/kg. Three conditions: THC only, THC+CBD, placebo. Adults showed reduced ventral striatum activation under THC; adolescents did not.
How They Did This
Double-blind, placebo-controlled, randomized crossover design. 47 participants (24 adolescents ages 16-17, 23 adults ages 26-29) matched on cannabis use frequency completed the Monetary Incentive Delay task during fMRI after inhaling THC alone, THC+CBD, or placebo.
Why This Research Matters
The developing adolescent brain may process cannabis differently than the adult brain. Understanding these age-dependent effects on reward circuits is critical for assessing the unique risks cannabis poses to younger users.
The Bigger Picture
Reward system development is a key feature of adolescence. If THC affects reward processing differently in teens versus adults, age-specific risk communication and policy approaches may be warranted rather than one-size-fits-all messaging.
What This Study Doesn't Tell Us
Moderate sample size (47 total). Participants were existing cannabis users (0.5-3 days/week), so findings may not generalize to naive users. Single-session design cannot address repeated exposure effects. THC dose was relatively low.
Questions This Raises
- ?Does the lack of reward blunting in adolescents reflect resilience or a different vulnerability pattern?
- ?Would higher or repeated doses produce different age-dependent effects?
Trust & Context
- Key Stat:
- THC blunted reward brain activity in adults but not in 16-17 year olds
- Evidence Grade:
- Randomized, placebo-controlled crossover design with neuroimaging is rigorous. Moderate sample size and single-session design are limitations.
- Study Age:
- Published 2022.
- Original Title:
- The Effects of Acute Cannabis With and Without Cannabidiol on Neural Reward Anticipation in Adults and Adolescents.
- Published In:
- Biological psychiatry. Cognitive neuroscience and neuroimaging, 8(2), 219-229 (2023)
- Authors:
- Skumlien, Martine(4), Freeman, Tom P(51), Hall, Daniel(3), Mokrysz, Claire, Wall, Matthew B, Ofori, Shelan, Petrilli, Kat, Trinci, Katie, Borissova, Anna, Fernandez-Vinson, Natalia, Langley, Christelle, Sahakian, Barbara J, Curran, H Valerie, Lawn, Will
- Database ID:
- RTHC-04949
Evidence Hierarchy
Participants are randomly assigned to treatment or placebo groups to test cause and effect.
What do these levels mean? →Frequently Asked Questions
Does this mean cannabis is safer for teens than adults?
Not at all. The absence of acute reward blunting in adolescents does not mean cannabis is safe for teens. It may reflect different neural mechanisms that could carry their own risks, including altered reward development. The adolescent brain is still maturing, and other studies link teen cannabis use to long-term cognitive and mental health outcomes.
What does reward anticipation mean in brain imaging?
The Monetary Incentive Delay task shows participants cues signaling they can win or lose money. Brain regions involved in motivation and reward, especially the ventral striatum, activate in anticipation of the reward. Reduced activation can indicate blunted reward processing.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-04949APA
Skumlien, Martine; Freeman, Tom P; Hall, Daniel; Mokrysz, Claire; Wall, Matthew B; Ofori, Shelan; Petrilli, Kat; Trinci, Katie; Borissova, Anna; Fernandez-Vinson, Natalia; Langley, Christelle; Sahakian, Barbara J; Curran, H Valerie; Lawn, Will. (2023). The Effects of Acute Cannabis With and Without Cannabidiol on Neural Reward Anticipation in Adults and Adolescents.. Biological psychiatry. Cognitive neuroscience and neuroimaging, 8(2), 219-229. https://doi.org/10.1016/j.bpsc.2022.10.004
MLA
Skumlien, Martine, et al. "The Effects of Acute Cannabis With and Without Cannabidiol on Neural Reward Anticipation in Adults and Adolescents.." Biological psychiatry. Cognitive neuroscience and neuroimaging, 2023. https://doi.org/10.1016/j.bpsc.2022.10.004
RethinkTHC
RethinkTHC Research Database. "The Effects of Acute Cannabis With and Without Cannabidiol o..." RTHC-04949. Retrieved from https://rethinkthc.com/research/skumlien-2023-the-effects-of-acute
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.