Using marijuana can promote the onset of mania symptoms and potentially exacerbate them in those suffering from bipolar disorder.
Steven Marwaha, PhD, of Warwick Medical School, Coventry, United Kingdom, and colleagues reviewed existing studies involving cannabis use. In those six studies, 2,391 individuals had mania symptoms. The mean length of follow-up was 3.9 years.
“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?,” Marwaha said in a statement. “But also, does cannabis use increase the risk of onset of mania symptoms in those without pre-existing bipolar disorder?”
A review of the literature found that cannabis use preceded or coincided with mania symptoms, rather than cannabis use following mania symptoms, the researchers wrote in the Journal of Affective Disorders. In addition, using marijuana significantly worsened mania symptoms in people diagnosed with bipolar disorder.
A meta-analysis of two studies suggested that cannabis use is associated with an approximately three-fold (Odds Ratio: 2.97; 95% CI: 1.80–4.90) increased risk for the new onset of manic symptoms.
“Our review suggests that cannabis use is a major clinical problem occurring early in the evolving course of bipolar disorder,” Marwaha noted.
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 School carried 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.