A cognitive signature of metabolic health in effort-based decision-making

Survival necessitates a delicate balance between expending effort to obtain resources, and energy conservation. Individual differences in motivation, the tendency to expend effort, play a fundamental role in society, affecting health, education, and economic outcomes. Previous theories explain variations in motivation via dopaminergic function. However, insulin resistance could also alter motivated behaviour by shifting the balance toward energy conservation. In a preregistered experiment, we investigated whether blunted motivational tendency—reduced tendency to exert effort, quantified using economic decision-making models, and previously linked to neuropsychiatric symptoms— is present in type-2 diabetes. We found subjects with type-2 diabetes showed this cognitive signature of blunted motivational tendency, compared to matched non-diabetic controls. Across a large sample with and without diabetes, we found that increasing risk for diabetes linearly predicted blunted motivational tendency. Diabetic patients treated with semaglutide did not show restored motivational tendency. Metabolic ill-health is associated with a shift towards energy conservation, potentially contributing to comorbidity between metabolic disease and mental illness.