Emotions, particularly negative affect such as depression and anxiety, play important roles in the etiology and maintenance of substance use disorders, as well as in response to treatment. For example, studies with alcohol-dependent patients have shown that ongoing depression increases the risk of relapse during and after treatment [1–3], and sudden increases in negative affect have been shown to immediately precede nicotine relapse .
One of the ways in which negative mood may lead to substance use is through its effect on craving for alcohol and other drugs. Several current models of substance use disorder etiology or relapse have offered explanations for the interplay among negative mood, craving, and substance use. For example, learning-based models postulate that substance abusers learn that use of alcohol and drugs can temporarily alleviate painful emotions. After such learning has occurred, negative emotions trigger the desire for alcohol or drugs, which in the immediate absence of alcohol or drugs is experienced as craving. The craving in turn then drives the substance abuser to seek out and use alcohol or drugs in an effort to reduce the negative affect .