Abstinence violation effect refers to the guilt and perceived loss of control that a person feels whenever he or she slips and finds himself or herself returning to drug use after an extended period of abstinence.
Other definition:
Abstinence violation effect refers to a person's sense of loss of control over his/her Behavior that has an overwhelming and demoralizing effect.
Other /More definition:
Abstinence violation effect refers to a feeling of loss of control that results when one has violated self-imposed rules, such as not to smoke or drink.

Abstinence violation effect is what happens when a person attempting to abstain from alcohol use ingests alcohol and then endures conflict and guilt by making an internal attribution to explain why he or she drank, thereby making him or her more likely to continue drinking in order to cope with the self-blame and guilt
Other /More definition:

Abstinence Violation Effect refers to what happens when a person attempting to abstain from alcohol use ingests alcohol and then endures conflict and guilt by making an internal attribution to explain why he or she drank, thereby making him or her more likely to continue drinking in order to cope with the self-blame and guilt