How important are positive and negative outcome expectancies in the treatment of addiction: a narrative review of the literature

The purpose of this paper is to review the substance misuse literature on how outcome expectancies are measured, how they are related with the level of use and other factors as well as their role into treatment and recovery.

A narrative review of the literature for all major substances of abuse was undertaken.

Existing measurement tools are substance specific. Most research has been in the field of alcohol, and involved students or light and moderate drinkers. Positive expectancies have been found to be related to initiation and level of alcohol, nicotine and cannabis use and also to be modifiable with repeated cue exposure. Negative expectancies have been found to be associated with prevention of smoking, positive changes in drinking and positive effect on treatment outcome for alcohol.

Both positive and negative outcome expectancies have been found to predict development of substance misuse and recovery from it respectively, but cross-substance comparisons are hindered by lack of appropriate measures.

The concept of outcome expectancies is present in several theories of addiction. To date there has been no comprehensive review of the extent to which different types of expectancy play a role in different substances and their treatment.