Deficits in behavioural inhibition in substance abuse and addiction: A meta-analysis

image - Gambling Square
Date Commenced:
01/2012
Project Supporters:

The work was supported by a UNSW Vice-Chancellor’s Postdoctoral Research Fellowship

Project Members: 
image - 1314679466 Janette Smith 09
Research Fellow
Ph (02) 9385 0274
image - Jaimi Iredale Square
Miss Jaimi Iredale
Research Assistant
Project Main Description: 

Deficits in behavioural inhibitory control are attracting increasing attention as a factor behind the development and maintenance of substance dependence. However, evidence for such a deficit is varied in the literature. A meta-analysis of published results indicated that substance use disorders and addiction-like behavioural disorders are associated with impairments in inhibitory control, although the size of this effect varies between drug classes and inhibitory tasks.

Project Collaborators: External: 

Dr Sharna Jamadar
Monash University

Rationale: 

The results reported in the literature to date are contradictory and suffer from small sample sizes. Previous meta-analyses have either considered only one drug type (e.g., alcohol) or collapsed across several types of drug. We conducted a meta-analysis to find the overall effect for several classes of drugs, as well as for addiction-like behavioural disorders.

Aims: 

To provide a weighted mean effect size estimate for several classes of drugs, for inhibitory measures as well as general performance measures.

Design and Method: 

A literature search revealed 97 papers suitable for inclusion in the meta-analysis. We considered two measures of behavioural inhibition and three other general performance measures.

Findings: 

Inhibitory deficits were small-to-medium on the whole, and stronger for stimulants (cocaine, methamphetamine, ecstasy, and to a lesser extent, tobacco). Small deficits were observed for alcohol dependence and non-dependent heavy drinking. Opioid users, cannabis users and internet addicts showed no deficit in inhibition, while gamblers displayed a strong deficit. For the most part, these performance deficits were specific to inhibition, and not displayed for general performance measures.

Output: 

Smith JL, Mattick RP, Jamadar SD & Iredale JM (2014) Deficits in behavioural inhibition in substance abuse and addiction: A meta-analysis. Drug and Alcohol Dependence, 145, 1-33.

Benefits: 

The project has found solid support for the concept of a behavioural control deficit in abusers of some but not all substances. This will contribute to a narrowing of theory concerning the importance of inhibitory control to the development and maintenance of substance abuse disorders.

Project Research Area: 
Project Status: 
Completed
Year Completed: 
2014