The University of Chicago, Department of Psychiatry Behavioral Neuroscience, 5841 S. Maryland Ave., MC3077, Chicago IL 60637, United States
Present address: The University of Illinois at Chicago, Department of Psychiatry, 1601 W. Taylor St., MC912, Chicago, Illinois 60612
•We assessed effects of delta-9- tetrahydrocannabinol (THC) on responses to the Trier Social Stress Test (TSST) in healthy volunteers.
•THC produced nonlinear dose effects upon emotional responses to the TSST.
•7.5 mg THC dampened negative emotional responses without influencing performance.
•12.5 mg THC slightly but significantly increased negative affect overall.
•12.5 mg THC impaired TSST performance and attenuated blood pressure responses.
Cannabis smokers often report that they use the drug to relax or to relieve emotional stress. However, few clinical studies have shown evidence of the stress-relieving effects of cannabis or cannabinoid agonists. In this study, we sought to assess the influence of delta-9-tetrahydrocannabinol (THC), a main active ingredient of cannabis, upon emotional responses to an acute psychosocial stressor among healthy young adults.
In comparison to placebo, 7.5 mg THC significantly reduced self-reported subjective distress after the TSST and attenuated post-task appraisals of the TSST as threatening and challenging. By contrast, 12.5 mg THC increased negative mood overall i.e., both before and throughout the tasks, and pre-task ratings of the TSST as threatening and challenging. It also impaired TSST performance and attenuated blood pressure reactivity to the stressor.
Our findings suggest that a low dose of THC produces subjective stress-relieving effects in line with those commonly reported among cannabis users, but that higher doses may non-specifically increase negative mood.