Cannabis and Anxiety: A Critical Review of the Evidence

Crippa, J.A., Zuardi, A.W., Martin-Santos, R., Bhattacharyya, S., Atakan, Z., McGuire, P., & Fusar-Poli, P. (2009). Cannabis and anxiety: A critical review of the evidence. Human Psychopharmacology Clinical and Experimental, 24(7), 515 - 523. doi: 10.1002/hup.1048

Cannabis can precipitate intense and short term anxiety, similar to a panic attack, in individuals who do not use regularly. This risk is especially present when high doses are administered (>5mg oral delta-9 tetrahydrocannabinol) and when the user is in an unknown or stressful context (Crippa et al., 2009).

Such anxious reactions are a deterrent to further use of cannabis, as they are often cited as the reason a person quit their use (Crippa et al., 2009). depression-medical-marijuana-300x218.jpg

Interestingly, cannabis can worsen a person's current anxiety symptoms, can increase the likelihood that acute episodes will happen again, and can interfere with the effects of anti-anxiety medication (Crippa et al., 2009).

On the other hand, habitual users state that cannabis use aids in decreasing their anxiety. Relaxation and stress relief are the most common impacts of using cannabis and are the most prevalent reasons individuals give for using the drug (Crippa et al., 2009).

Individuals who use cannabis appear to have increased anxiety relative to non-users, which does not necessarily meet criteria for a clinical disorder (Crippa et al., 2009).

Long-term cannabis use has been correlated with a greater prevalence of comorbidity with anxiety disorders, most notably panic and social anxiety disorders (Crippa et al., 2009).

A significant amount of individuals develop anxiety disorder prior to cannabis dependence, implicating that they use cannabis to self-medicate (Crippa et al., 2009).

It was found that frequent cannabis use in teenage girls doubled their risk of developing anxiety and depression, and that daily use quadrupled this risk (Crippa et al., 2009).

The main psychoactive substance in cannabis, delta-9 THC, could promote anxiety by impacting serotonin, noradrenalin, GABA, and glutamate (Crippa et al., 2009).

Being under the influence of cannabis could promote anxiety through decreased cognitive functioning and lack of awareness (Crippa et al., 2009).

There is speculation that other parts of the cannabis plant may affect its psychoactive influences. For instance, cannabidiol (CBD) makes up 40% of cannabis extracts, and rather than relating to changes in psychological and thought processes, it is purported to have anti-anxiety effects (Crippa et al., 2009).

There are many motives for why people decide to use substances . Substances are used to cope with stress by functioning to reducecannabis-460_873120c.jpg negative affect or to increase positive affect (Hyman & Sinha, 2009). Substance abuse is most likely when life stress is high and when adaptive coping strategies are lacking, especially in regards to cannabis (Hyman & Sinha, 2009). Stress is an important factor to consider when it comes to cannabis for two reasons:

  • The body’s stress arousal system is directly affected by cannabis ingestion, and
  • It has consistently been cited as important both in maintaining cannabis use but also as a reason for chronic use (Hyman & Sinha, 2009).
There are three factors to consider:

  • Family dysfunction,
  • Stressful life events (including traumatic stress), and
  • Maladaptive strategies in coping with stress (Hyman & Sinha, 2009)

Studies show that the most common motive for cannabis use is to achieve a “mellow” or relaxed feeling which is much less reported for any other drug category (stimulants, hallucinogens, depressants, and narcotics) (Hyman & Sinha, 2009). This suggests that there is a greater use of cannabis associated with the reduction of tension caused by stress compared to other drugs (Hyman & Sinha, 2009). It has also been found that smoking cannabis for coping with stress is reported more often by heavy cannabis users than by experimental or occasional users (Hyman & Sinha, 2009). This suggests that coping motives may be more common in chronic users of cannabis (Hyman & Sinha, 2009). Using cannabis for coping purposes may be more common in chronic users because they are lacking alternative effective coping strategies (Hyman & Sinha, 2009). It is also possible that stress systems are affected by the chronic use of cannabis, making stress-related motivation to use more salient for these chronic users (Hyman & Sinha, 2009). It was found that chronic cannabis use alters stress response and enhances drug craving and negative emotions during induction of stress and drug cue exposure in addicted individuals compared to controls (Hyman & Sinha, 2009).

Sarah Russo Perspective : Medical Marijuana