The die is cast: Decision-making under risk and under ambiguity in schizophrenia and alcohol use disorder

Background: Patients with schizophrenia (SZ) tend towards riskier decision-making (DM). Yet, the specificity of these findings, as well as the impact of impairments in executive functioning (EF) has not been sufficiently clarified. Method: In a preregistered study (https://osf.io/n7z6y) 40 SZ, 50 patients with alcohol use disorder (AUD), and 36 healthy controls (HC) completed an n-back task (as EF challenge), the Game of Dice Task (GDT; DM under risk) and the Iowa Gambling Task (IGT; DM under ambiguity).Results: AUD and SZ performed worse than HC in the n-back task, and riskier in the GDT. In the IGT, only AUD performed riskier than HC and preferred the disadvantageous deck B compared to SZ. However, controlling for demographics and IQ abolished significance. Correlations of performance in the GDT and IGT with working memory differed between groups.Conclusion: Both patient groups show a deficit in the reflective system, while only AUD show impairments in the impulsive system. The direct comparison of DM in SZ and AUD suggests a differential DM profile of SZ and AUD. Our results propose that both groups may benefit from EF training, especially in planning, categorization, and cognitive flexibility, while AUD could additionally profit from impulse control and inhibition training. However, the findings need replication with well-matched samples, and the link between EF and DM in SZ should be examined more carefully with experimental approaches.