Neural and neurocognitive markers of vulnerability to gambling disorder: a study of unaffected siblings.

Psychological and neurobiological markers in individuals with gambling disorder (GD) could reflect transdiagnostic vulnerability to addiction or neuroadaptive consequences of long-term gambling. Using an endophenotypic approach to identify vulnerability markers, we tested the biological relatives of cases with GD. Male participants seeking treatment for GD (n = 20) were compared with a male control group (n = 18). Biological siblings of cases with GD (n = 17, unrelated to the current GD group) were compared with a separate control group (n = 19) that overlapped partially with the GD control group. Participants completed a comprehensive assessment of clinical scales, neurocognitive functioning, and fMRI of unexpected financial reward. The GD group displayed elevated levels of self-report impulsivity and delay discounting, and increased risk-taking on the Cambridge Gamble Task. We did not observe impaired motor impulsivity on the stop-signal task. Siblings of GD showed some overlapping effects; namely, elevated impulsivity (negative urgency) and increased risk-taking on the Cambridge Gamble Task. We did not observe any differences in the neural response to win outcomes, either in the GD or sibling analysis compared with their control group. Within the GD group, activity in the thalamus and caudate correlated negatively with gambling severity. Increased impulsivity and risk-taking in GD are present in biological relatives of cases with GD, suggesting these markers may represent pre-existing vulnerability to GD.

Heterogeneity in Disordered Gambling: Decision-Making and Impulsivity in Gamblers Grouped by Preferred Form.

Background: Previous research has indicated that disordered gamblers display deficits in impulsivity and risky decision-making, compared to healthy control groups. However, disordered gamblers are not a homogenous group, and differences in performance on neurocognitive tasks may be related to the form of gambling in which an individual chooses to engage. The present study used neurocognitive tasks and questionnaire measures to ascertain group differences in gamblers grouped by preferred form of gambling. Method: Treatment-seeking pathological gamblers from the National Problem Gambling Clinic, London (n = 101), completed a neurocognitive assessment comprising the Cambridge gamble task (CGT), the stop-signal task (SST), a probabilistic reversal learning task (PRL), and the Kirby Monetary Choice Questionnaire, as well as questionnaire measures of gambling severity, impulsivity, depression, and anxiety. Analyses compared gamblers who favored fixed-odds betting terminals (FOBTs) (the modal form) to gamblers who preferred other forms of gambling (non-FOBT). Results: The FOBT group showed impaired decision-making under risk on the CGT compared to the non-FOBT group, choosing the likely option less on more uncertain decisions. The FOBT group made fewer perseverative errors on the PRL task, had lower depression and anxiety scores, and were less likely to have a family history of problem gambling than the non-FOBT group. Discussion: Decision-making and cognitive flexibility differences between gamblers grouped by gambling type supports preferred form as an important source of heterogeneity in gambling disorder. Decision-making strategies and risk attitudes should be considered when approaching cognition-focused treatment strategies, allowing interventions to be targeted at specific cognitive deficits.