WARWICK, England, Monday February 16, 2015 – As the debate continues to rage over the possible risks or advantages of smoking marijuana, new research out of Britain’s Warwick University has found a “significant link” between marijuana use and mania, which can range from hyperactivity and difficulty sleeping to aggression, becoming delusional and hearing voices.
Published in the Journal of Affective Disorders, the study of more than 2,000 people suggested potentially alarming consequences for teenagers who smoke the herb.
“Cannabis [marijuana] is the most prevalent drug used by the under-18s,” said lead researcher Dr Steven Marwaha.
“During this critical period of development, services should be especially aware of and responsive to the problems cannabis use can cause for adolescent populations.”
Researchers examined the effect of marijuana on individuals who had experienced mania, a condition that can include feelings of persistent elation, heightened energy, hyperactivity and a reduced need for sleep.
On the other side of the coin, mania can make people feel angry and aggressive with extreme symptoms including hearing voices or becoming delusional.
“Previously it has been unclear whether cannabis use predates manic episodes,” Dr Marwaha said.
“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?”
Dr Marwaha found that marijuana use tended to precede or coincide with episodes of mania.
Representing what the lead researcher referred to as “a significant link,” there was a strong association with new symptoms of mania, suggesting that these are caused by marijuana use.
The researchers also found that marijuana 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,” Dr Marwaha said.
“However, our review suggests 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 effected by genetic vulnerability and environmental risk factors.”
These findings add to a body of previous studies that have linked marijuana to increased rates of mental health problems including anxiety, depression, psychosis and schizophrenia, and have suggested that the herb is addictive and opens the door to hard drugs.
A study which was published in the journal Neuroscience earlier this month nevertheless found that marijuana could be used to treat depression.
Scientists at the University of Buffalo’s Research Institute on Addictions said molecules present in marijuana could help relieve the depression resulting from long-term stress.