Is there any interaction with weed and quetiapine?

Also I am thinking of stopping my quetiapine. The reasons for this is that I don't really suffer with manic/psychotic episodes (only when I drink but I have stopped drinking). Also it makes me feel that sluggish that I have stopped exercising and it has made me pile on the pounds too which has actually made me more depressed than I was before. I know that it was the alcohol making me go crazy not my mental illness, hence the reason I have given up drink.
So I have been on them less than a year and I am taking 100mg in the morning and 300mg at bed time. Just wondering what people have experienced on coming off them and what would happen if I went cold turkey?#

Kez xx