Research published in the journal Drug and Alcohol Dependence concluded that low levels of Tetrahydrocannabinol (THC) , the main psychoactive compound in Marijuana does reduce stress, but in a highly dose-dependent manner. They found very low doses lessened the anxiety of a public speaking task but slightly higher doses actually increased anxiety. Researchers said “We found that THC at low doses reduce stress, while higher doses had the opposite effect, underscoring the importance of dose when it comes to THC and its effect.” They pointed out that few studies previously looked at the effects of THC on stress and the differences related to dose because of the difficulty of obtaining samples and the regulation of the category 1 substance.
Healthy volunteers age 18 to 40 who had some experience with cannabis use but not daily users were recruited for the study. They were randomly divided into 3 groups: 1) the low dose group received one capsule of 7.5 mg THC daily: 2) the moderate group received a capsule of 12.5 mg daily: and 3) the placebo group received a capsule containing none. Neither researchers or group members knew who was receiving what dose. Researchers said: The doses used in the study produce effects that are equivalent to only a few puffs of a cannabis cigarette.” Researchers further said it is difficult to compare doses of smoked cannabis to doses of engested THC. “We didn’t want to include larger doses because we wanted to avoid potential adverse effects or cardiovascular effects that can result from higher doses of THC.”
Subjects attended two four hour sessions with researchers five days apart. At each session they took their capsules and then relaxed for two hours to allow the RHC to be absorbed. During one session subjects were asked ro spend 10 minutes preparing for a mock job interview. This was followed by a 5 minute interview with a lab assistant who did not offer feedback. They were then asked to count backwards from a five digit number by subtracting 13 for 5 minutes. According to the researcher this task is very stress producing.
In their second visit subjects were asked to talk with lab assistants about a favorite book or movie for five minutes and then play solitaire for five minutes. Before, during and after each activity subjects were asked to rate their stress levels and feelings about the tasks. In addition, blood pressure, heart rate, and cortisol levels (a key stress hormone) were measured. Those who received 7.5mg of THC reported less stress after the psycho-social test than those given a placebo and their stress levels dissipated faster after the test. Subjects who received 12.5 mg of THC reported greater negative mood before and throughout the task, and were more likely to rate the psychosocial task as challenging and threatening beforehand and had more pauses during the mock interview compared to those in the placebo group. Researchers concluded “Our findings provide some support for the common claim that cannabis is used to reduce stress and relieve tension and anxiety.” “At the same time, our findings our finding that participants in the higher THC group reported smaller but significant increases in anxiety and negative mood throughout the test supports the idea that THC can also produce the opposite effect.?