Study proves cannabis does not cause anxiety and depression

We always knew it, but now it's scientifically proven: cannabis does not increase the risk of developing anxiety or depression, a new study has found.

There has long been debate over the drug’s potential link to mental health problems.But finally a study by scientists at Columbia University, based on 35,000 American adults, found no link between cannabis and anxiety and depression.

The research, published in the journal JAMA Psychiatry, challenges previous thinking on the effects of using the class B drug. Public health bodies have often cited a link between cannabis and depression.

After controlling for a variety of confounding factors, such as socio-demographic characteristics, family history and environment, and past and present psychiatric disorders, the study found that “cannabis use was not associated with increased risk of developing mood or anxiety disorders.”

Don’t break out the celebratory blunt just yet, though. The study did find an association between marijuana use and later substance-use disorders, such as abuse of and dependence on alcohol, tobacco, marijuana and other drugs. But this isn’t necessarily surprising: It’s fairly obvious that if you use a substance, you’re putting yourself at risk of a substance-use disorder.

Dr Amir Englund, a post-doctoral researcher in psychopharmacology at the Institute of Psychiatry, Psychology and Neuroscience at King's College London, said: 

"They found that use of cannabis was related to increased risk of later addiction to alcohol, cannabis and other drugs. Cannabis was not related to anxiety or depression at follow-up.