Global reward processing deficits predict negative symptoms transdiagnostically and transphasically in a severe...

Area of Science:

• Neuroscience
• Psychiatry
• Clinical Psychology

Background:

• Impaired reward processing is linked to negative symptoms in severe mental illnesses.
• Previous research shows inconsistent findings regarding specific reward processing deficits and their association with negative symptoms.

Purpose of the Study:

• To investigate if mixed findings stem from multiple reward processing pathways to negative symptoms.
• To examine if these pathways are transdiagnostic and transphasic.

Main Methods:

• Recruited healthy controls (n=100) and a severe mental illness-spectrum sample (n=92) including clinical high-risk for psychosis, bipolar disorder, and schizophrenia.
• Administered tasks measuring RDoC Positive Valence System constructs: value representation, reinforcement learning, effort-cost computation, and hedonic reactivity.
• Utilized k-means cluster analysis to identify reward processing profiles within the severe mental illness sample.

Main Results:

• Identified three clusters in the severe mental illness sample: global reward deficits (22.8%), selective hedonic reactivity deficits (40.2%), and preserved reward processing (37%).
• Elevated negative symptoms were exclusively found in the global reward processing deficit cluster.
• All clusters included participants from all clinical groups, indicating transdiagnostic patterns.

Conclusions:

• A transdiagnostic and transphasic pathway involving global reward processing deficits contributes to negative symptoms.
• Findings suggest equifinality, where different clinical groups converge on similar reward processing deficits leading to negative symptoms.
• Further research into divergent pathways can inform personalized treatments for negative symptoms in severe mental illnesses.