There is a ton of information and most of it is contradictory.
Anyone could win a debate on either side of the argument using articles based on findings from medical studies.
It is as important to look closely at the company or organization that funds the study as well as the findings themselves.
Politics often finds its way into such studies.
Is Marijuana dangerous can depend on what other substance we use for comparison? If we compare cannabis to a long list of FDA approved medications and the deaths and health complications attributed to said medications then Marijuana wins that argument.
When pot is compared to other illegal "recreational drugs" it is the lesser of two evils.
On the other hand just because there isn't a line outside Drug Detox Clinics for those that smoke Marijuana doesn't mean users are totally out of the woods.
A recent study at King's College in London found that small amounts of trahydrocannabinol (THC), an active ingredient in marijuana, used by subjects in the study caused psychotic symptoms which included paranoia and hallucinations.
Using MRI scans researchers discovered that the inferior frontal cortex which regulates paranoia is adversely affected by THC.
Many patients in Drug Rehab Centers have a duel diagnosis; that is addiction and a mental health issue.
Could there be a connection? There are no easy answers and in the end people have to make up their own minds.
I just think there has to be more intense research by impartial laboratories before we have a definitive answer.