Early Huntington's Disease: Impulse Control Deficits but Correct Judgment Regarding Risky Situations

Huntington's disease (HD) patients show alterations in decision making tasks. However, it is still uncertain if these deficits are due to poor judgment regarding risky situations, or to impulse control deficits.

To elucidate whether decision-making in patients is related to genuine risk behavior or to impulse control deficits.

To test between these two alternative possibilities, we evaluated the performance of 19 prodromal HD patients and 19 matched healthy controls in the Cambridge Gambling Task (CGT). This task assesses decision-making while dissociating between genuine risk-taking behaviors (ascending condition) from impulsive behavior (descending condition).

The results showed that patients and controls had the same performance during all trials in the ascending condition, reflecting a correct judgment regarding risky situations; however, during the descending condition, patients responded before the controls in all trials, making a significantly larger number of higher bets. Unlike the control group, they did not wait for more optimal subsequent options.

These results suggest impulse control deficits in HD gene carriers, but unimpaired risk-taking judgment.