Discounting delayed monetary rewards and decision making in behavioral addictions - A comparison between patients with gambling disorder and internet gaming disorder.

Behavior addictions, such as Gambling Disorder and Internet Gaming Disorder, have been demonstrated to have severe negative impact. Heightened impulsivity, deficits in decision making, and cognitive biases in the preference of immediate rewards have been shown to be crucial aspects in addictive disorders. While for Gambling Disorder (GD), dysfunctional decision making has been documented before, data for Internet Gaming Disorder (IGD) are still underrepresented. In order to allow for a direct comparison of both disorders, we assessed different measures of impulsivity (trait, impulsive choice, and decision making) in a clinical sample. N = 31 patients meeting criteria for GD and n = 30 patients with IGD were recruited from an outpatient clinic and compared regarding their performance in a Delay Discounting Task (DDT), the Iowa Gambling Task (IGT), and self-report data on impulsivity (Barratt Impulsiveness Scale). Healthy controls (n = 27) were included as a reference group. In the DDT, the area under the curve was associated with the severity of GD only. No correlations were found for the impulsivity subscales and the area under the curve which, however, was similar between the two patient groups in contrast to controls. The GD-group performed poorer then the other groups in the IGT while IGD-patients performed poorer only at the beginning of the experiment. Although only few significant differences occurred, similarities between GD and IGD regarding the DDT point towards a tendency on discounting rewards faster. Likewise, both patient groups were performing worse in the IGT than healthy controls which indicates deficiencies in decision making. Interestingly, the IGD-group was able to shift towards more advantageous decision making, which might have important implications for therapeutic interventions.