Luke Clark¹, Andrew J. Lawrence¹, Barbara J. Sahakian², Trevor W. Robbins¹.
The 61st Annual Convention of the Society of Biological Psychiatry, Toronto, Canada, May 18th-20th, 2006
1. Department of Experimental Psychology, University of Cambridge, Cambridge, United Kingdom
2. Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom

Background: Questionnaire data and neuropsychological assessment have indicated increased impulsivity in various substance user populations, including stimulant, opiate, and alcohol abusers. These deficits may represent a vulnerability marker for addiction or may occur as a consequence of chronic drug exposure. Problem gambling has been described as a prototypical ‘drug free’ addiction where the neurobiological consequences of addiction may be minimised.

Methods: We administered a neuropsychological and clinical assessment to a group of community-recruited problem gamblers (n=15, all male, mean age 37, South Oaks Gambling Screen?5, mean=12) and non-gambling controls (n=13). Clinical scales were used to assess impulsivity (Barratt), adult ADHD and OCD characteristics, and alcohol and drug use. Two neuropsychological measures of impulsivity were administered: the Stop Signal Task (SST) and the Information Sampling Task (IST) (to assess pre-decisional ‘reflection’ impulsivity).

Results: Preliminary analyses indicated significantly elevated Barratt impulsivity ratings in the problem gamblers (p<.0001) but no significant group differences on the neuropsychological tests. The problem gamblers showed increased drug use relative to controls (DAST-10, p=.013), and inflated scores on the Padua OCD scale (p=.016) and the ASRS adult ADHD scale (p=.001).

Conclusions: Problem gamblers show increases in questionnaire impulsivity that are qualitatively similar to deficits seen in substance users. However, problem gamblers appear to be relatively intact on neuropsychological measures of inhibitory control. The problem gamblers also showed increased drug use relative to controls, as well as elevated scores on OCD and adult ADHD rating scales, suggesting that any underlying endophenotype may not be specific to addiction.