Shifting uncertainty intolerance: methylphenidate and attention-deficit hyperactivity disorder

Abstract Risk evaluation is a critical component of decision making. tolerance relevant in both daily decisions and pathological disorders such as attention-deficit hyperactivity disorder (ADHD), where impulsivity cardinal symptom. Methylphenidate, commonly prescribed drug ADHD, improves attention but has mixed reports on risk-based Using double-blinded placebo protocol, we studied the risk attitudes ADHD patients age-matched healthy volunteers while performing 2-step sequential learning task examined effect methylphenidate their choices. We then applied novel computational analysis using hierarchical drift–diffusion model to extract parameters threshold (‘ ’—amount evidence accumulated before making decision), drift rate v ’—information processing speed) response bias ( ‘z’ apriori towards specific choice) focusing specifically risky choice preference. Critically, show that have an choices compared controls. Furthermore, enhanced preference (higher bias) groups had significantly greater patient population independent clinical scores. Thus, appears shift uncertain possibly mediated by prefrontal dopaminergic noradrenergic modulation. emphasise utility models detecting underlying processes. Our findings implications for subtle yet differential effects population.