Hi there ~
Although there are no studies that show that recreational marijuana use has serious side effects, there are case reports of marijuana use on a recreational basis causing psychological effects and precipitating depression
. There is also evidence of other medical problems when the marijuana is "dirty" i.e. laced with other chemicals and substances. I would encourage you to research more on the ill effects of marijuana on the national institute of health website.
I hope this helps. Take care and have a lovely day!