Taking a look at studies of marijuana from 1999 to present

Mia De Graaf reports for The Daily Mail,

Marijuana DOES cause schizophrenia and triggers heart attacks, experts say in landmark study that slams most of the drug's medical benefits as 'unproven'

Marijuana does raise the risk of getting schizophrenia and triggers heart attacks, according to the most significant study on the drug's effects to date.

A federal advisory panel admitted cannabis can almost certainly ease chronic pain, and might help some people sleep.
But it dismisses most of the drug's other supposedly 'medical benefits' as unproven.

Crucially, the researchers concluded there is not enough research to say whether marijuana effectively treats epilepsy - one of the most widely-recognized reasons for cannabis prescriptions.

The report also casts doubt on using cannabis to treat cancers, irritable bowel syndrome, or certain symptoms of Parkinson's disease, or helping people beat addictions.

The report lists nearly 100 conclusions about marijuana and its similarly acting chemical cousins, drawing on studies published since 1999.

It found strong evidence, for example, that marijuana can treat chronic pain in adults and that similar compounds ease nausea from chemotherapy, with varying degrees of evidence for treating muscle stiffness and spasms in multiple sclerosis.

...Substantial evidence links pot smoking to worse respiratory symptoms and more frequent episodes of chronic bronchitis.

Read more here.