Review finds 'significant link' between cannabis use and onset of mania symptoms

http://www.eurekalert.org/pub_releases/2015-02/uow-rf021015.php

Public Release: 10-Feb-2015
University of Warwick

Researchers from the University of Warwick have found evidence to suggest a significant relationship between cannabis use and the onset and exacerbation of mania symptoms.

In a paper published in the Journal of Affective Disorders, mental health researchers from Warwick Medical Schoolcarried out a review of scientific literature examining the effect of cannabis use. The literature sampled 2,391 individuals who had experienced mania symptoms.

Mania symptoms are part of bipolar disorder and can include feelings of persistent elation, heightened energy and hyperactivity and a reduced need for sleep. Mania can also make people feel angry and aggressive with extreme symptoms including becoming delusional or hearing voices.

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The researchers looked at a number of previous studies and concluded that cannabis use preceded the onset of mania symptoms.

Dr Marwaha said: "The observed tendency for cannabis use to precede or coincide with rather than follow mania symptoms, and the more specific association between cannabis use and new onset manic symptoms, suggests potential causal influences from cannabis use to the development of mania. It is a significant link."

Dr Marwaha also said the review suggested that cannabis use significantly worsened mania symptoms in people who had previously been diagnosed with bipolar disorder.

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