Dynamic risk control by human nucleus accumbens

Real-world decisions about reward often involve a complex counterbalance of risk and value. Although the nucleus accumbens has been implicated in the underlying neural substrate, its criticality to human behaviour remains an open question, best addressed with interventional methodology that probes the behavioural consequences of focal neural modulation. Combining a psychometric index of risky decision-making with transient electrical modulation of the nucleus accumbens, here we reveal profound, highly dynamic alteration of the relation between probability of reward and choice during therapeutic deep brain stimulation in four patients with treatment-resistant psychiatric disease. Short-lived phasic electrical stimulation of the region of the nucleus accumbens dynamically altered risk behaviour, transiently shifting the psychometric function towards more risky decisions only for the duration of stimulation. A critical, on-line role of human nucleus accumbens in dynamic risk control is thereby established

Introduction

SummaryIn the past serendipity and good clinical observation were essential for the discovery of new drug treatments for mental disorders. Today, neurochemical and pharmacological research allows development of compounds starting from hypothesis on the origin of the disorders and the actions of available drugs. The new compounds are cleaner from the pharmacological point of view, more specific and therefore with less undesired effects. Venlafaxine is one of these drugs and provides antidepressant efficacy in a broad range of depressed patients, including the most severe ones, with a good safety and tolerability profile.</jats:p