Effect of psychostimulants on impulsivity and risk taking in narcolepsy with cataplexy.

Objective: To investigate the effect of psychostimulants on impulsivity, depressive symptoms, addiction, pathological gambling, and risk-taking using objective sensitivity tests in narcolepsy with cataplexy (NC). Drug-free patients with NC present alterations in reward processing, but changes with psychostimulants remain unknown.

Design: Prospective case-control study.

Setting: Academic sleep disorders center.

Participants: There were 120 participants: 41 drug-free patients with NC, 37 patients with NC taking psychostimulants, and 42 matched healthy controls.

Interventions: All participants underwent a semistructured clinical interview for impulse control and addictive behaviors and completed questionnaires for depression and impulsivity. Risk taking was analyzed through performance on a decision-making task under ambiguity (Iowa Gambling Task [IGT]) and under risk (Game of Dice Task [GDT]). All patients with NC underwent 1 night of polysomnography followed by a multiple sleep latency test for drug-free patients and a maintenance wakefulness test for treated patients.

Results: Depressive symptoms were higher in drug-free patients than in treated patients and controls, with no difference between controls and treated patients. No between-group differences were found for impulsivity, substance addiction, or pathological gambling. Drug-free and treated patients showed selective reduced performance on the IGT and normal performance on the GDT compared with controls, with no differences between patients taking medication and those who did not. No clinical or polysomnographic characteristics or medication type was associated with IGT scores.

Conclusions: Our results demonstrated that, whether taking psychostimulants or not, patients with narcolepsy with cataplexy preferred risky choices on a decision-making task under ambiguity. However, the lack of association with impulsivity, pathological gambling, or substance addiction remains of major clinical interest in narcolepsy with cataplexy.