Tolerance Breaks Were a Risk Marker in One Cannabis Study, Not a Proven Cause of Harm

Young adults who reported cannabis tolerance breaks had higher subsequent hazardous-use and disorder-severity scores in an observational study. That association does not show that taking a break caused worsening cannabis problems.

What counted as a tolerance break

The analysis followed 170 recreational cannabis users aged 18–30 over six months. Participants described breaks intended to reduce tolerance separately from breaks taken for work, relationships, access or other reasons. About 17% reported a tolerance break; some participants reported both types of break.

The researchers adjusted for baseline outcomes and measured characteristics, including use frequency. Participants chose whether and why to take breaks. They were not randomly assigned to abstain, and neither a fixed cannabis dose nor a standardized break schedule was imposed.

Positive and null results need to stay together

Reporting a tolerance break was associated with higher six-month hazardous-use scores and cannabis-use-disorder severity. It was not significantly associated with six-month use frequency or withdrawal symptoms. Tolerance-break duration was not significantly associated with the measured outcomes.

For breaks taken for other reasons, longer duration was associated with lower hazardous-use scores, lower disorder severity and lower use frequency. Merely reporting such a break was not significantly associated with these outcomes. Duration and the presence of a break are different comparisons.

Why the study cannot determine causation

Someone experiencing escalating use or tolerance may be more likely to try a tolerance break. That pathway can produce an association even if the break itself did not worsen the problem. Adjustment helps with measured differences but cannot resolve all changes in motivation, consumption or symptoms during follow-up.

Break histories and cannabis use were self-reported retrospectively. Withdrawal questions covered a broad period rather than the specific break, and the tolerance-break subgroup was small. The study did not measure THC in blood, urine or oral fluid, receptor recovery, driving performance or biochemical reversal of tolerance.

The findings support asking why a person is taking a break and what happens afterward. They do not establish that abstaining causes harm, identify a universally effective break length, or validate a date when someone can safely drive or pass a drug test.

Related analysis: evaluating cannabis tolerance claims.

Primary research

Ansell EB; Bedillion MF; Farris SR; Gilbert JM; Koch MM; Thureen SE. Cannabis use breaks in young adults: The highs and lows of tolerance breaks. Drug and alcohol dependence (2023). DOI: 10.1016/j.drugalcdep.2023.109951.