The influence of dimensional psychopathology on social reward processing

Abstract

Social reward processing is a key mechanism underpinning human social interaction. The feelings of reward attached to social interaction help to motivate future social behaviour and inform preferences for different types of social contact. As with other forms of reward, there is increasing evidence to suggest that psychopathology affects social reward processing, leading to the atypical interpersonal behaviour that defines some psychopathologies. This thesis, therefore, aimed to develop the findings of previous research and examined associations between social reward processing and dimensional psychopathology. It addressed five research questions. (1) Is atypical social reward processing a transdiagnostic characteristic of psychopathology? To answer this question, a systematic review and meta-analysis of existing research investigating social reward processing in clinical versus healthy control groups was conducted (Chapter 3). (2) Do clinical versus control group differences in social reward processing translate dimensionally within the normative population? To probe this, associations between psychopathology and measures of social reward processing were investigated in a general population sample (n = 154; Chapter 4). (3) Are dimensions of psychopathology differently related to the behavioural processing of various social reward subtypes (Admiration, Negative Social Potency, Passivity, Sociability)? This was also examined in a general population sample (n = 42). (4) Are these dimensional relationships detectable in forensic psychiatric service users? This was explored in a pilot sample (n = 15) using the same approach as used in the general population sample (Chapter 6). (5) How does intranasal oxytocin administration influence social reward processing in dimensional psychopathology? This question was addressed using a within-subjects, placebo-controlled design (n = 17) with double-blind acute administration of oxytocin to healthy adults (Chapter 7). The presented findings suggest that psychopathology is associated with atypical social reward processing. Reduced processing of social rewards linked to schizophrenia spectrum and autism spectrum dimensions was observed in multiple chapters, with several psychopathological dimensions also showing an increased preference for antisocial rewards involving witnessing or enacting cruelty to others. Furthermore, Chapters 3 and 4 demonstrated the potential utility of transdiagnostic approaches in social reward research and, collectively, the findings presented across this thesis highlight the importance of including social reward subtypes within characterisations of social reward processing. As such, these studies provide new insight into links between psychopathology and social reward processing and provide a theoretical and methodological foundation for larger work investigating social reward processing in psychopathology.