I have quit smoking for good. But, I have smoked on and off for about 2 years. I’d say my longest period of smoking was about 9 months. About a thimble size amount of pot being smoked once a day. Of course also the rare time of more than that. No cigarettes, just marijuana .
(Don’t need to hear peoples opinions on brain damage. And yes i say opinion.)
http://www.videojug.com/expertanswer/marijuana-side-effects-2/does-marijuana-cause-brain-damage