Overview
- In adults, risk of any cannabis use disorder rose above roughly 8.26 THC units per week, with moderate to severe risk increasing past about 13.44 units.
- Adolescents showed lower thresholds around 6.04 units for any disorder and about 6.45 units for moderate to severe cases, indicating higher vulnerability at lower use levels.
- One standard unit equaled 5 mg THC, derived from a 12‑month London study of 150 participants that used receiver operating characteristic analyses to classify risk.
- The models showed good to excellent accuracy, with particularly strong discrimination in adolescents and high sensitivity across thresholds reported between 86% and 91%.
- Illustrative estimates suggest a strong herbal joint in the U.K. can approach about 13 THC units, while typical hash or resin joints may contain about 5 to 6 units and weaker herbal joints about 3 to 4 units.