Chronic Δ9-tetrahydrocannabinol exposure during adolescence is associated with persistent behavioural tolerance in adult nonhuman primates.
Yasaman Razavi, Stephen J Kohut, Jack Bergman, Brian D Kangas
British Journal of Pharmacology November 1, 2025 DOI: 10.1111/bph.70179 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Population | Female and male adolescent nonhuman primates |
| Intervention | Δ9-THC |
| Dose | 0.32 mg kg-1 day-1 or 3.2 mg kg-1 day-1 |
| Duration | 6-month chronic exposure, approximately 1-year abstinence, then acute testing |
| Topics | Cannabis |
| Keywords | Adolescence Attentional processes Nonhuman primates Touchscreen cognition Δ9‐tetrahydrocannabinol |
| Citations | 1 |
| Key findings | Adolescent exposure to chronic Δ9-THC led to increased tolerance to Δ9-THC-induced attentional deficits in adulthood, requiring higher doses to impair performance. |
Abstract
Legalisation of Cannabis use has led to considerable increases in the availability and potency of Cannabis products, as well as evolving patterns in methods of their consumption. Adolescent Cannabis use has increased, which can impair cognitive function during this critical developmental stage. The persistence of such effects into adulthood, however, is unclear. The present study examined whether chronic Δ9-tetrahydrocannabinol (Δ9-THC) exposure during adolescence modifies subsequent Δ9-THC-induced cognitive deficits during adulthood. Female and male adolescent nonhuman primates were treated intramuscular daily for 6 months with either vehicle, a low dose of Δ9-THC (0.32 mg kg-1 day-1), or a high dose (3.2 mg kg-1 day-1). Approximately 1 year after discontinuing chronic exposure, these subjects, now adults, were trained on a touchscreen-based Psychomotor Vigilance Task (PVT) to examine attentional processes. Acute doses of Δ9-THC were administered prior to select test sessions via two routes, intramuscular or oral, to evaluate the roles of adolescent drug history and method of consumption on Δ9-THC-induced attentional deficits. Results confirm dose-related Δ9-THC impairment of PVT performance by both intramuscular and oral routes of administration, notwithstanding differences in potency and onset of action. Adolescent drug history modified tolerance to Δ9-THC impact on attentional processes, where subjects exposed to chronic Δ9-THC during adolescence required higher doses of Δ9-THC during adulthood to impair PVT performance. These findings suggest a persistent impact of adolescent Δ9-THC use that, even following extended abstinence, may present itself during adulthood via increased tolerance to Cannabis products.
Comparable studies
Other preclinical and animal studies on cannabis, most cited first.
Citations in the library
Cites 13
- Tolerance and cross-tolerance to neurocognitive effects of THC and alcohol in heavy cannabis users Psychopharmacology October 30, 2010
- Cannabis Use and Neuroadaptation: A Call for Δ9-Tetrahydrocannabinol Challenge Studies Frontiers in Psychiatry April 14, 2022
- Central Executive Network drives delta-9-tetrahydrocannabinol (THC)-induced nonlinear changes in large-scale functional connectivity in adolescent nonhuman primates. Neuropsychopharmacology October 1, 2025
- Chronic Δ9-tetrahydrocannabinol exposure in adolescent nonhuman primates: persistent abnormalities in economic demand and brain functional connectivity. Neuropsychopharmacology February 1, 2025
- Adolescents are more sensitive than adults to acute behavioral and cognitive effects of THC. Neuropsychopharmacology June 1, 2022
and 8 more in the library