Journal Article

Baseline impulsivity may moderate L-DOPA effects on value-based decision-making

Pooseh, Shakoor, Lee, Ying, Smolka, Michael N., Kienast, Annika, London, Edythe D., Goschke, Thomas, Petzold, Johannes

2019

Overview

Research has indicated a major role of dopamine in decision-making processes, but the underlying mechanisms remain largely unknown due to inconsistency in effects of dopaminergic drugs. To clarify the impact of dopamine on impulsive choice, we administered 150 mg L-DOPA to 87 healthy adults in a randomized, placebo-controlled, double-blind, crossover study, evaluating performance in four value-based decision-making tasks. We predicted that baseline impulsivity would moderate L-DOPA effects. In support of our hypothesis, L-DOPA had no main effect on impulsive choice, but reduced risk-seeking for gains in more-impulsive subjects. Because L-DOPA effects may be influenced by body weight, we repeated our analyses on data from half of the sample (n = 44) with lower weight, anticipating a stronger effect. In addition to the effect on risk-seeking for gains, low-weight participants also exhibited baseline-dependent effects of L-DOPA on loss aversion and delay discounting. Our results are consistent with the hypothesis of an inverted U-shaped dopamine function in which both low and high extremes of dopamine signaling are associated with high-impulsive choice. Consideration of differential baseline impulsivity and body weight may resolve previous seemingly paradoxical pharmacological results and might deepen our understanding of dopaminergic mechanisms underlying impulsivity.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 631/378/2649/1409 / 631/378/2649/2150 / 631/477/2811 / 692/308/575 / Adult / Aversion / Body weight / Body Weight - physiology / Brain - drug effects / Choice Behavior - drug effects / Choice Behavior - physiology / Cross-Over Studies / Data processing / Decision making / Decision Making - physiology / Delay Discounting / Dihydroxyphenylalanine / Dopamine / Dopamine - metabolism / Dopamine - pharmacology / Dopamine - physiology / Dopamine Agents - pharmacology / Dopamine receptors / Double-Blind Method / Female / Humanities and Social Sciences / Humans / Hypotheses / Impulsive behavior / Impulsive Behavior - drug effects / Impulsive Behavior - physiology / Impulsivity / Levodopa / Levodopa - pharmacology / Male / multidisciplinary / Prefrontal Cortex - drug effects / Random Allocation / Reward / Risk reduction / Science / Science (multidisciplinary)