Cannabis and anxiety : a critical review of the evidence, José Alexandre Crippa et al., 2009

Cannabis and anxiety: a critical review of the evidence

José Alexandre Crippa, Antonio Waldo Zuardi, Rocio Martin-Santos, Sagnik Bhattacharyya,
Zerrin Atakan, Philip McGuire and Paolo Fusar-Poli

Human Psychopharmacology Clinical and Experimental, 2009, 24, 515-523.


Background : Anxiety reactions and panic attacks are the acute symptoms most frequently associated with cannabis use. Understanding the relationship between cannabis and anxiety may clarify the mechanism of action of cannabis and the pathophysiology of anxiety. Aims of the present study were to review the nature of the relationship between cannabis use and anxiety, as well as the possible clinical, diagnostic and causal implications.

Method : Systematic review of the Medline, PsycLIT and EMBASE literature.

Results : Frequent cannabis users consistently have a high prevalence of anxiety disorders and patients with anxiety disorders have relatively high rates of cannabis use. However, it is unclear if cannabis use increases the risk of developing long-lasting anxiety disorders. Many hypotheses have been proposed in an attempt to explain these relationships, including neurobiological, environmental and social influences.

Conclusions : The precise relationship between cannabis use and anxiety has yet to be established. Research is needed to fully clarify the mechanisms of such the association.

Key words : Cannabis sativa; tetrahydrocannabinol; cannabidiol; anxiety; psychosis