What happens if you quit using morphine cold turkey?

It's not physically addictive, so there are no physical withdrawal symptoms. The person will just be extremely, horribly depressed for awhile, and their brain will crave a meth high to make them feel better again.

They will also probably sleep a lot (both because they haven't been sleeping enough for awhile and because they're so depressed, and sleep is an escape) and they may also eat a lot, both because they haven't been eating enough for awhile, and because they are using food as a replacement drug.