Impulsivity is a prominent feature of pathological gamblers. Numerous studies have reported elevated scores on a constellation of impulsivity-related traits measured using psychometric instruments, including sensation seeking and novelty seeking (Castellani and Rugle, 1995; Cunningham-Williams et al., 2005; Kim and Grant, 2001; Lawrence et al., 2009b; McCormick et al., 1987). In a recent study, Lawrence and colleagues (2009a) observed significant increases on the BIS-11 and the Adult ADHD Self-Report Scale (ASRS) (Kessler et al. 2004) in both problem gamblers and individuals with alcohol dependence. These elevated scores were increased to greater extent than the compulsivity scores as measured by the Padua Inventory, a measure of subclinical obsessive compulsive disorder (OCD) symptoms. While earlier studies have reported significant increases on other compulsivity scales in pathological gamblers (Blaszczynski, 1999; Frost et al., 2001), a recent study conducted by Blanco and colleagues (2009) examined the relationship between gambling symptoms, impulsivity, and compulsivity in 38 pathological gamblers who were participating in a trial of the selective serotonin reuptake inhibitor, paroxetine. The correlation between gambling severity and compulsivity did not withstand statistical control for impulsivity,
