fMRI findings in motivational behaviour of Pathological Gamblers – A central role of the striatum

Pathological gambling (PG) is characterized by compulsive repetitive uncontrolled gambling despite negative consequences. Studies on substance dependence indicate that a key characteristic in addiction is a dysregulation of the reward brain circuitry, in particular the striatum. In patients addicted to a substance a very salient cue, like a drug, is necessary to significantly activate the reward system. For pathological gambling, the debate is ongoing as to whether the underlying neurobiological mechanisms are similar. Preliminary findings show increased striatum activity in reward anticipation as well as in motor response in the patient group. On feedback controls activate higher in the striatum. Previous findings showed a decreased activation of the striatum when assessing reward sensitivity on monetary win in PG. This is in line with our results, indicating decreased reward sensitivity (striatum) in PG on feedback for monetary win compared to healthy controls. The urge to gamble repeatedly can be explained with classical conditioning where casino surroundings (sounds, visual cues etc) evoke excitement because of their association with intermittent money win. Gamblers receive rewarding signals before they are confronted with gains or losses. Therefore the motivation to win as well as the gambling behaviour itself and not so much the monetary gain might play an important role in sustaining pathological gambling behaviour despite the negative consequences. Our results provide further evidence on reclassifying PG as behavioural addiction and also offer insights into behaviour change interventions.

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Pathological Gambling - Reward - Striatum