A systematic review examined whether cognitive and psychomotor impairment from cannabis persists into the next day, finding variable evidence across studies.
Workplace safety professionals, driving regulators, cannabis consumers, and occupational health physicians.
Variable next-day effectsTHC cognitive impairment may persist but is inconsistent across studies, doses, and cognitive domains
What the researchers found
The review found that next-day cognitive and psychomotor effects of THC are possible but inconsistent, with effects varying by dose, frequency of use, and the specific cognitive domains assessed.
Why it matters
Next-day cannabis effects have major implications for driving, workplace safety, and daily functioning. Clarifying whether impairment persists helps set evidence-based waiting periods for safety-sensitive activities.
The numbers in context
THC is the main intoxicating component of cannabis, and the review examined whether impairment persists many hours or days after use.
How the study worked
Systematic review of studies examining cognitive and psychomotor performance at time points beyond acute cannabis intoxication.
Who was studied
Cannabis users assessed for cognitive and psychomotor performance at next-day or later time points.
What this study cannot tell us
Heterogeneity in study designs, doses, assessment timing, and outcome measures; few studies specifically designed to assess next-day effects; tolerance effects complicate interpretation.
How to read the evidence
Systematic review provides comprehensive evidence synthesis; underlying study quality and design vary.
When this study was published
Recent systematic review addressing a practically important safety question.
The bigger picture
This review provides the evidence base needed for developing rational waiting-period guidelines for driving and safety-sensitive tasks after cannabis use.
Replication
Comprehensive review; highlights need for standardized next-day assessment protocols.
Funding
Not specified
Conflicts of interest
Not specified
Questions still open
- How long do effects truly persist after high-dose consumption?
- Do edibles produce longer next-day effects than inhalation?
- Should workplace policies account for next-day impairment?
Read the original research
The "Next Day" Effects of Cannabis Use: A Systematic Review.
Cannabis and cannabinoid research, 8(1), 92-114
Citation
McCartney, Danielle; Suraev, Anastasia; McGregor, Iain S. (2023). The "Next Day" Effects of Cannabis Use: A Systematic Review.. Cannabis and cannabinoid research, 8(1), 92-114. https://doi.org/10.1089/can.2022.0185