From premature to protracted decision-making: Neural mechanisms underlying transdiagnostic biases in deliberation

Deciding when to decide is challenging, and disrupted deliberation processes are central to several mental illnesses. On one extreme, overconfident jumping-to-conclusions (JTC) is common in schizophrenia (SCZ) and may drive delusions. On the other, a pervasive indecisiveness (IND) and doubt is common in obsessive-compulsive disorder (OCD) and is linked to compulsions. Despite the importance of this JTC-IND symptom dimension – and its life-changing impact highlighted by our lived-experience representatives (LERs) – these biases are not commonly targeted in therapy, and their underlying neural mechanisms remain mysterious. In this interdisciplinary, translational, and transdiagnostic project, we will investigate the nature and plasticity of the behavioural, neural, pharmacological and computational mechanisms underlying this JTC-IND spectrum in multiple patient populations and healthy volunteers. By combining approaches from neuroimaging in patients to rodent optogenetics, we will pin down the neurocomputational mechanisms causing deliberation biases in mental illnesses, and by probing how these processes can be changed, we will develop novel interventions targeting these mechanisms. With clinical practitioners, LERs, and experts in computational modelling and neuroscience, we are ideally placed to understand this critical transdiagnostic symptom spectrum with its direct translational potential, helping both those drawing hasty decisions as well as those trapped in their hesitations.