From that article:
"""Conclusions Despite all of the uncertainties surrounding the cannabis-psychosis link... The evidence suggests that cannabis is associated with an increased risk of psychosis when it is used frequently. Whether cannabis can trigger a primary psychotic disorder that would not have otherwise occurred is unclear.
However, in most individuals who use cannabis, psychosis does not develop, which suggests that the increased risk must be related to other vulnerability factors (genetics, frequency, or age of onset of cannabis misuse)."""
Yes, but only to those who are already disposed.
That having been said, I think that it is different than what the GP was referring to which is a chemical addictive property (like nicotine) rather than a long/short term side effect (smoking side effects, whether it be tar in your lungs or increased risk of schizophrenia)
[1] Sorry for the language, but the biggest joke of this entire debate is that Cannabis is a schedule 1 drug.
The evidence for a link between Cannabis and increased risk of psychosis is increasing [1]. A patient with psychosis rarely recovers and is extremely costly to society over his lifetime (as well as a personal tragedy, of course). I'm in favour of legalisation but it is something to take into account.
[1] http://www.psychiatrictimes.com/schizophrenia/content/articl...