In Mom's makeup case. In the refrigerator. All of these and many other drugs. They feel a sense of loss about giving up drugs. The levels of dopamine in their brain are severely depleted and can remain depleted for a year or more.
Most addicts have an underlying clinical depression and require antidepressant therapy.
They haven't learned to deal with life events without using drugs. Chronic drug use creates biochemical changes in the brain that generate an intense biological imperative to seek drugs. They miss the social experience of getting high. They have not experienced severe enough consequences to want to stop using. Doctors recommend pregnant women drink no more than 2 glasses of wine per day and avoid hard liquor.