Acute Marijuana Effects on Human Risk Taking

Summary & key facts

In a small lab study, 10 adults who used marijuana occasionally smoked placebo and three active marijuana cigarettes with different THC levels. The highest THC dose (3.58% Δ9-THC) led people to choose the risky option more often on a decision task. Detailed trial-by-trial analysis showed the high dose changed how people reacted after winning or losing, suggesting altered sensitivity to consequences under acute marijuana intoxication.

Key facts:

• Ten adults (5 men, 5 women) participated. Their average age was 24.5 years (range 19–38).
• Participants reported using marijuana an average of 7.4 times in the previous 30 days (SEM = 1.35, range 1–14).
• Subjects completed four drug conditions in a within-subject design: placebo and three active smoked marijuana doses (one mixed half-placebo/half 1.77% Δ9-THC, one 1.77% Δ9-THC, and one 3.58% Δ9-THC).
• Only the highest active dose (3.58% Δ9-THC) increased selection of the risky response option on the laboratory task.
• Trial-by-trial analyses showed the 3.58% THC dose changed response probabilities after both wins and losses following risky choices, which the authors interpret as altered sensitivity to reinforcing and aversive outcomes.
• The study was small (N=10), used occasional marijuana users in a controlled lab task, and therefore the findings describe acute, short-term effects in this specific setting rather than long-term or real-world outcomes.

Topics

Cannabis and Cannabinoid Research Child and Adolescent Psychosocial and Emotional Development Substance Abuse Treatment and Outcomes

Categories

Health Sciences Medicine Pharmacology

Tags

Alternative medicine Drug Injury prevention Medical emergency Medicine Pathology Placebo Poison control Psychiatry Psychology

Substances

Cannabis