Risk-taking decisions in pathological gamblers is not a result of their impaired inhibition ability.

This work investigates whether inhibition impairments influence the decision making process in pathological gamblers (PGs). The PG (N=51) subjects performed the Iowa Gambling Task (IGT as the measure of the decision making process) and two tests of inhibition: the Stroop (interference inhibition), and the Go/NoGo (response inhibition), and were compared with demographically matched healthy subjects (N=57). Performance in the IGT block 1 and block 2 did not differ between the groups, but the differences between the PGs and healthy controls began to be significant in block 3, block 4 and block 5. PGs learned the IGT task more slowly than the healthy controls and had non-optimal outcomes (more disadvantageous choices). Impaired IGT performance in PGs was not related to an inhibition ability measured by the Stroop (interference response time) and the Go/NoGo (number of commission errors) parameters. Further controlled studies with neuroimaging techniques may help to clarify the particular brain mechanisms underlying the impaired decision making process in PGs.