According to the authors, pathological gambling, which is classified as an impulse control disorder, has been described as a drug-free addiction. As with other impulse control disorders, urges usually precede engagement in associated self-destructive behaviors and therefore represent important targets for therapeutic interventions.

Marc N. Potenza, M.D., Ph.D., and his American colleagues investigated brain function in male pathological gamblers and non-gamblers with use of functional magnetic resonance imaging while participants viewed videos depicting happy events, sad events, and a gambling situation. Participants rated the quality and strength of emotional responses, as well as any urge to gamble, produced by watching the videos.

The researchers found that the 10 pathological gamblers reported greater gambling urges after viewing the gambling videos than the 11 participants who were non-gamblers. The 2 groups of participants did not differ significantly in their responses to happy and sad videos.

The most pronounced functional differences between the groups were observed during the initial period of viewing the gambling scenarios. Participants with pathological gambling had decreased activity in regions of the brain believed to be involved in impulse control compared with activity in participants who were not gamblers. The greatest difference in activity was seen during the initial phase of viewing the gambling scenario. Pathological gamblers had relatively decreased activity in frontal and orbitofrontal cortex, caudate and basal ganglia, and thalamus.

"The finding of distinct patterns of neural responses to gambling-related stimuli that are unique from those to other internal (emotional) states has direct clinical implications and provides a basis for future experimentation in the prevention and treatment of pathological gambling," wrote the authors.