Stress, motivation, and drug addiction

A growing clinical literature indicates that there is a link between substance abuse and stress. One explanation for the high co-occurrence of stress-related disorders and drug addiction is the self-medication hypothesis, which suggests that a dually diagnosed person often uses the abused substance to cope with tension associated with life stressors or to relieve symptoms of anxiety and depression resulting from a traumatic event. However, another characteristic of self-administration is that drug delivery and its subsequent effects on the hypothalamic-pituitary-adrenal (HPA) axis are under the direct control of the individual. This controlled activation of the HPA axis may produce an internal state of arousal or stimulation that is actually sought by the individual. During abstinence, exposure to stressors or drug-associated cues can stimulate the HPA axis and thereby remind the individual about the effects of the abused substance, thus producing craving and promoting relapse. Stress reduction, either alone or in combination with pharmacotherapies targeting the HPA axis, may prove beneficial in reducing cravings and promoting abstinence in individuals seeking treatment for addiction.