As certain U.S. states move to legalize marijuana, Colorado leading the charge, many wonder about the safety of smoking the plant. After all, advertisers told us for years that smoking tobacco was safe and even promoted it as a weight-loss tool.
Luckily researchers are continuing to do what they do best: question our assumptions and shed light on what is true vs. what is not true.
In this case, researchers from the University of Warwick Medical School, have found evidence to suggest a significant relationship between cannabis use and the onset and increase of mania symptoms. Mania symptoms are associated with bipolar disorders and can include feelings of persistent elation, increased energy, hyperactivity, a reduced need for sleep, anger, aggression, delusions, and hallucinations.
The paper, published in the Journal of Affective Disorders (February 2015), was a review of scientific literature examining the effect of cannabis use. The paper strove to answer two questions: 1) Does cannabis use lead to increased occurrence of mania symptoms or manic episodes in individuals with pre-existing bipolar disorder?, and 2) does cannabis use increase the risk of onset of mania symptoms in those without pre-existing bipolar disorder?
In both cases the answer was not only “yes,” but a significant link between use and mania became evident. According to the authors, cannabis use significantly worsened mania symptoms in people who had previously been diagnosed with bipolar disorder. More research is needed, suggested the authors, to consider specific pathways from cannabis use to mania and how these may be effected by genetic vulnerability and environmental risk factors.
"Cannabis is the most prevalent drug used by the under-18s and during this critical period of development services should be especially aware of and responsive to the problems that cannabis use can cause for adolescent populations,” warned the authors.
Gibbs, M. et al. Cannabis use and mania symptoms: A systematic review and meta-analysis. Journal of Affective Disorders, 2015; 171: 39 DOI:10.1016/j.jad.2014.09.016