Cannabis and anxiety: a critical review of the evidence

Authors

  • José Alexandre Crippa,

    1. Department of Neurosciences and Behavior, Division of Psychiatry, Ribeirão Preto School of Medicine, University of São Paulo (USP-RP) and INCT Translational Medicine, Brazil
    2. Department of Psychological Medicine, Section of Neuroimaging, Institute of Psychiatry, Kings College London, London, UK
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    • Professor.

  • Antonio Waldo Zuardi,

    1. Department of Neurosciences and Behavior, Division of Psychiatry, Ribeirão Preto School of Medicine, University of São Paulo (USP-RP) and INCT Translational Medicine, Brazil
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    • Full Professor and Head of the Department of Neurosciences and Behavior.

  • Rocio Martín-Santos,

    1. Department of Psychological Medicine, Section of Neuroimaging, Institute of Psychiatry, Kings College London, London, UK
    2. Neuropsychopharmacology Group, IMIM-Hospital del Mar and Department of Psychiatry; Institute of Neuroscience, Hospital Clinic, IDIBAPS, CIBERSAM, Barcelona, Spain
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  • Sagnik Bhattacharyya,

    1. Department of Psychological Medicine, Section of Neuroimaging, Institute of Psychiatry, Kings College London, London, UK
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  • Zerrin Atakan,

    1. Department of Psychological Medicine, Section of Neuroimaging, Institute of Psychiatry, Kings College London, London, UK
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  • Philip McGuire,

    1. Department of Psychological Medicine, Section of Neuroimaging, Institute of Psychiatry, Kings College London, London, UK
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    • Full Professor and Head of the Neuroimaging Section.

  • Paolo Fusar-Poli

    Corresponding author
    1. Department of Psychological Medicine, Section of Neuroimaging, Institute of Psychiatry, Kings College London, London, UK
    2. Department of Health Sciences, Section of Psychiatry, University of Pavia, Pavia, Italy
    • Neuroimaging Section, PO67 Department of Psychological Medicine, Institute of Psychiatry, De Crespigny Park 103, King's College London, SE5 8AF London, UK.
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Abstract

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. Copyright © 2009 John Wiley & Sons, Ltd.

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