Residual and enduring effects of cannabis use on cognitive and psychomotor function: A study of adults during unrestricted cannabis use, short-term abstinence, and protracted abstinence.

The impact of cannabis on cognitive and psychomotor function is important to understand, given the role of the endocannabinoid system in these critical processes. The literature has shown robust acute negative effects of cannabis on cognition and psychomotor skills during intoxication, and to a lesser degree, persisting effects following short-term abstinence up to 4 weeks. However, whether these decrements resolve after long-term cessation of use remains unclear. We evaluated cognitive and psychomotor function in 31 adults with current cannabis use during unrestricted use (UNR) and after a 3-day abstinence (RES), 23 adults with former cannabis use (> 90 days abstinent; FU), and 58 nonusing controls (CON) using the cognition and motor batteries of the National Institutes of Health Toolbox. Linear mixed models showed no significant differences in cognitive and motor performance between UNR, RES, and FU groups. Group effects emerged such that CON outperformed UNR on the Oral Reading Recognition Test, and CON outperformed both UNR and RES on the Picture Vocabulary Test. In terms of psychomotor function, FU, RES, and UNR performed better than CON on the Grip Strength Test. In this comprehensive examination of cognitive and psychomotor performance in adults with cannabis use with 3 days to > 90 days of abstinence, our results indicated that the cognitive impacts of chronic, heavy cannabis use are observable during short-term abstinence but remit after > 90 days of abstinence. This highlights widespread impacts of cannabis use abstinence across cognitive and psychomotor domains. Future studies are needed to evaluate whether these effects are also observable with use reduction, as opposed to abstinence. (PsycInfo Database Record (c) 2025 APA, all rights reserved).