The Contribution of Apathy and Increased Learning Trials to Risky Decision-Making in Parkinson's Disease

We aimed to study whether previously described impairment in decision making under risky conditions in patients with Parkinson's disease (PD) is affected by deficits in using information about potential incentives or by processing feedback (in terms of fictitious gains and losses following each decision). Additionally, we studied whether the neural correlates of using explicit information in decision making under risk differ between PD patients and healthy subjects. We investigated ten cognitively intact PD patients and twelve healthy subjects with the Game of Dice Task (GDT) to assess risky decision making, and with an fMRI paradigm to analyse the neural correlates of information integration in the deliberative decision phase. Behaviourally, PD patients showed selective impairment in the GDT but not on the fMRI task that did not include a feedback component. Healthy subjects exhibited lateral prefrontal, anterior cingulate and parietal activations when integrating decision-relevant information. Despite similar behavioural patterns on the fMRI task, patients exhibited reduced parietal activation. Behavioural results suggest that PD patients’ deficits in risky decision making are dominated by impaired feedback utilization not compensable by intact cognitive functions. Our fMRI results suggest similarities but also differences in neural correlates when using explicit information for the decision process, potentially indicating different strategy application even if the interfering feedback component is excluded.

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Dopaminergic drugs decrease loss aversion in Parkinson’s disease with but not without depression

10.1101/069047 ◽

2016 ◽

Cited By ~ 1

Author(s):

Monique H.M. Timmer ◽

Guillaume Sescousse ◽

Rianne A.J. Esselink ◽

Payam Piray ◽

Roshan Cools

Keyword(s):

Parkinson’S Disease ◽

Decision Making ◽

Parkinson's Disease ◽

Loss Aversion ◽

Drug Effects ◽

Risky Choice ◽

Motor Symptom ◽

Risky Decision ◽

Dopaminergic Drugs ◽

Dopaminergic Medication

AbstractDepression, a common non-motor symptom of Parkinson’s disease (PD), is accompanied by impaired decision making and an enhanced response to aversive outcomes. Current strategies to treat depression in PD include dopaminergic medication. However, their use can be accompanied by detrimental side effects, such as enhanced risky choice. The mechanisms underlying dopamine-induced increases in risky choice are unclear. In the current study we adopt a clinical-neuroeconomic approach to investigate the effects of dopaminergic medication on loss aversion during risky choice in depressed and non-depressed PD. Twenty-three healthy controls, 21 depressed and 22 non-depressed PD patients were assessed using a well-established gambling task measuring loss aversion during risky choice. Patients were tested on two occasions, after taking their normal dopaminergic medication (ON) and after withdrawal of their medication (OFF). Dopaminergic medication decreased loss aversion to a greater extent in depressed than non-depressed PD patients. Moreover, we show that the degree to which dopaminergic medication decreases loss aversion correlated with current depression severity and with drug effects on depression scores. These findings demonstrate that dopamine-induced changes in loss aversion depend on the presence of depressive symptoms in PD.Significance statementDopaminergic medication that is used to treat motor and non-motor symptoms in patients with Parkinson’s disease is known to contribute to risky decision-making. The underlying mechanisms are unclear. The present study demonstrates that dopaminergic medication in Parkinson’s disease decreases loss aversion during risky choice, but only in depressed and not in non-depressed patients with Parkinson’s disease. These results advance our understanding of the mechanisms underlying dopamine-induced risky choice, while also identifying depression as an important factor that confers vulnerability to such dopamine-induced risky choice.Conflict of InterestThe authors declare no competing financial interests.

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