In summary, effects of marijuana on anxiety disorders are complex. The endocannabinoid system appears to play an important role in responses to stress and anxiety. The two primary active ingredients of marijuana, THC and CBD, appear to have differing effects with regard to anxiety. Pure THC appears to decrease anxiety at lower doses and increase anxiety at higher doses. On the other hand, pure CBD appears to decrease anxiety at all doses that have been tested. There appears to be tolerance to these effects over a short period of time with regular use. There are individual differences in responses to marijuana that are affected by a variety of factors. Many people report using marijuana to cope with anxiety, and this may be particularly common among those with social anxiety disorder. Those who are concerned about marijuana increasing anxiety are unlikely to use it whereas those who use it and find it to be beneficial presumably continue to use marijuana. Doing so may offer some benefit in the short term, at least in terms of anxiety, but well-controlled studies indicate that use of marijuana is associated with increased likelihood of substance use disorders in the future.