Deciphering reward-based decision-making in schizophrenia: A meta-analysis and behavioral modeling of the Iowa Gambling Task

• Published in: Schizophrenia Research Vol. 204; pp. 7 - 15
• Main Authors: Betz, Linda T., Brambilla, Paolo, Ilankovic, Andrej, Premkumar, Preethi, Kim, Myung-Sun, Raffard, Stéphane, Bayard, Sophie, Hori, Hikaru, Lee, Kyoung-Uk, Lee, Seung Jae, Koutsouleris, Nikolaos, Kambeitz, Joseph
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2019; Elsevier BV; Elsevier
• Subjects: [SHS.PSY]Humanities and Social Sciences/Psychology; Decision Making; Decision Making - physiology; Decision-making; Iowa Gambling Task; Linear modeling; Meta-analysis; Reward; Schizophrenia; Humanities and Social Sciences; Humans; Iowa Gambling Task; Linear modeling; Meta-analysis; Models, Theoretical; Psychology; Reward; Schizophrenia; Schizophrenia - physiopathology; Decision-making; Schizophrenia; Reward; Iowa Gambling Task; Linear modeling; Meta-analysis
• ISSN: 0920-9964; 1573-2509; 1573-2509
• DOI: 10.1016/j.schres.2018.09.009

Patients with schizophrenia (SZP) have been reported to exhibit impairments in reward-based decision-making, but results are heterogeneous with multiple potential confounds such as age, intelligence level, clinical symptoms or medication, making it difficult to evaluate the robustness of these impairments. We conducted a meta-analysis of studies comparing the performance of SZP and healthy controls (HC) in the Iowa Gambling Task (IGT) as well as comprehensive analyses based on subject-level data (n = 303 SZP, n = 188 HC) to investigate reward-based decision-making in SZP. To quantify differences in the influence of individual deck features (immediate gain, gain frequency, net loss) between SZP and HC, we additionally employed a least-squares model. SZP showed statistically significant suboptimal decisions as indicated by disadvantageous deck choices (d from 0.51 to −0.62) and lower net scores (d from −0.35 to −1.03) in a meta-analysis of k = 29 samples (n = 1127 SZP, n = 1149 HC) and these results were confirmed in a complementary subject-level analysis. Moreover, decision-making in SZP was characterized by a relative overweighting of immediate gain and net losses and an underweighting of gain frequency. Moderator analyses revealed that in part, decision-making in the IGT was moderated by intelligence level, medication and general symptom scores. Our results indicate robust impairments in reward-based decision-making in SZP and suggest that decreased cognitive resources, such as working memory, may contribute to these alterations.