Acute and chronic effects of cannabidiol on Δ⁹-tetrahydrocannabinol (Δ⁹-THC)-induced disruption in stop signal task performance.
Recent clinical and preclinical research has suggested that cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC) have interactive effects on measures of cognition however, the nature of these interactions is not yet fully characterized. To address this, we investigated the effects of Δ9-THC and CBD independently and in combination with proposed therapeutic dose ratios of 11 and 13 Δ9-THCCBD in adult rhesus monkeys (n 6) performing a stop signal task (SST). Additionally, the development of tolerance to the effects of Δ9-THC on SST performance was evaluated by determining the effects of acutely administered Δ9-THC (0.1-3.2 mgkg), during a 24-day chronic Δ9-THC treatment period with Δ9-THC alone or in combination with CBD. Results indicate that Δ9-THC (0.032-0.32 mgkg) dose-dependently decreased go success but did not alter go reaction time (RT) or stop signal RT (SSRT) CBD (0.1-1.0 mgkg) was without effect on all measures and, when coadministered in a 11 dose ratio, did not exacerbate or attenuate the effects of Δ9-THC. When coadministered in a 13 dose ratio, CBD (1.0 mgkg) attenuated the disruptive effects of 0.32 mgkg Δ9-THC but did not alter the effects of other Δ9-THC doses. Increases in ED50 values for the effects of Δ9-THC on SST performance were apparent during chronic Δ9-THC treatment, with little evidence for modification of changes in sensitivity by CBD. These results indicate that CBD, when combined with Δ9-THC in clinically available dose ratios, does not exacerbate and, under restricted conditions may even attenuate, Δ9-THCs behavioral effects. (PsycINFO Database Record