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.
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.
Lead author Dr Steven Marwaha said: “Previously it has been unclear whether cannabis use predates manic episodes. We wanted to answer two questions – does cannabis use lead to increased occurrence of mania symptoms or manic episodes in individuals with pre-existing bipolar disorder? But also, does cannabis use increase the risk of onset of mania symptoms in those without pre-existing bipolar disorder?”
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.”