The research began to establish a clear pattern of stress-induced craving for drugs -- both for those early in recovery and those who were actively using.
"Many people with those conditions aren't as aware of them as you would think, " says Dr. Clarke, who is president of the Psychophysiologic Disorders Association, a nonprofit advocacy group for stress-induced medical conditions.
"When you see someone's behavior, and their manner of stress-induced behavior, coupled with how their personality already is, I think it makes it easier to understand why something like this could possibly happen, " she told CNN Thursday.
"Having chocolate cravings is something that's induced by stress and probably is governed by body chemistry -- so it's not something you can control, " Drewnowski said.