Frontiers in Psychology
May 28, 2026
Lidia Venero-Hidalgo, Francisca Carvajal, Fernando Rodrı́guez de Fonseca et al.
Cannabis use during adolescence and young adulthood is linked to memory problems, especially in episodic and working memory, but effects on executive functions are less consistent and depend on age, how much cannabis is used, and the type of cognitive test. Studies from the Americas, many of which followed participants over time, more often found negative associations between cannabis use and cognitive performance. European studies showed mixed results, possibly due to differences in cannabis products, patterns of co-use, and measurement methods. Evidence from Asia was limited. Overall, cognitive differences are more reliably seen in adolescents than in young adults, shaped by developmental, methodological, and contextual factors.
Physiological research
May 12, 2026
M Bochin, Č Vejmola, V Koudelka et al.
Acute oral administration of THC (10 mg/kg), CBD (10 mg/kg), or their combination in freely moving rats alters resting-state EEG dynamics. THC and THC+CBD produced the strongest and most spatially extensive increases in low-frequency spectral power, with significant delta-beta clusters in prefrontal, cingulate, hippocampal, and striatal regions. CBD yielded fewer and smaller clusters. Connectivity analyses revealed altered functional coupling within overlapping CB1 receptor-rich regions. The combination treatment closely resembled THC alone, suggesting a dominant THC-driven contribution. These findings identify a cannabinoid-specific EEG signature of enhanced low-frequency oscillatory activity and altered large-scale network organization.
Biological psychiatry. Cognitive neuroscience and neuroimaging
May 1, 2026
Zachary Anderson, Matthew Gunn, Emily Jones et al.
A moderate oral dose of THC (7.5 mg) reduced resting-state functional connectivity within several brain networks, including corticostriatal circuits and networks involved in sensory processing, interoception, and spatial reasoning, in 33 healthy occasional young adult cannabis users. THC also decreased connectivity between two specific networks: one involving the anterior cingulate cortex and dorsal insula, and another involving the ventral insula and lingual gyrus. These connectivity changes were not related to subjective drug effects or recent cannabis use. The findings indicate that even a single moderate THC dose broadly disrupts intrinsic brain network connectivity.
Brain, behavior, and immunity
May 1, 2026
Havilah P Ravula, Barkha J Yadav-Samudrala, Laith E Sawaqed et al.
In a mouse model of HIV (Tg26 transgenic mice), chronic daily treatment with the cannabinoid THC for 90 days reduced the effects of a later high-dose THC challenge, particularly in females. Female mice with a history of chronic THC showed less THC-induced drop in body temperature, less pain relief, and less reduced movement after the acute high dose, and they also displayed more anxiety-like behavior on the elevated plus maze. HIV genotype influenced some of these effects. In the brain, chronic THC lowered levels of both pro- and anti-inflammatory cytokines in several regions of female mice, and HIV-positive mice showed increased microglial CCL3/MIP-1α co-occurrence in a sex- and brain-region-specific pattern.
JAMA network open
May 1, 2026
C Austin Zamarripa, Spencer Lin, Mckenna Klausner et al.
Combining cannabis edibles with alcohol worsens driving impairment more than either substance alone. In a controlled experiment with 25 healthy adults who reported prior co-use, driving performance was significantly impaired under most active drug conditions, including 25 mg THC with alcohol at 0.05% breath alcohol concentration. The legal alcohol intoxication limit of 0.08% may be too high when cannabis has also been consumed. Standard field sobriety tests often failed to detect impairment that was evident in driving measures. The findings suggest a need for better impairment detection and policies that account for co-use.