There is a significant relationship between cannabis use and the onset and exacerbation of mania symptoms, according to a recent study.

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.

Researchers at the University of Warwick carried out a review of scientific literature examining the effect of cannabis use. The literature sampled 2,391 individuals who had experienced mania symptoms.

"Previously it has been unclear whether cannabis use predates manic episodes," Dr. Steven Marwaha, lead author of the study, said in a statement. "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."

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

"There are limited studies addressing the association of cannabis use and manic symptoms, which suggests this is a relatively neglected clinical issue. However our review suggests that cannabis use is a major clinical problem occurring early in the evolving course of bipolar disorder. More research is needed to consider specific pathways from cannabis use to mania and how these may be affected by genetic vulnerability and environmental risk factors," he said.

The findings are detailed in the Journal of Affective Disorders.