"The captain wanted to stay with the sinking … (can't say boat)": How hypomanic personality traits interfere with inhibitory control?

Inhibitory control, the ability to suppress or countermand an action or thought, is notably impaired in patients with bipolar disorder. However, the specific characteristics of this impairment and whether deficits can manifest prior to a formal bipolar disorder diagnosis or among individuals with subsyndromal symptoms are relatively unknown. Here we test whether healthy individuals exhibiting a higher level of hypomanic personality traits respond more rapidly, albeit with weaker inhibitory control. We evaluated 83 native French speakers using the Hypomanic Personality Scale (HPS) and administered the Hayling Sentence Completion Test for response inhibition and the Stroop Test for interference control. We found negative correlations between the HPS score and both the response initiation and response inhibition times on the Hayling Sentence Completion Test, but the scores did not affect accuracy. Regarding the Stroop Test, we observed a significant positive correlation between the scores for hypomanic personality traits and the number of errors on the color-word condition. Our findings demonstrate that a high level of hypomanic personality traits correlates with faster reaction times on response inhibition tasks and higher error rates on interference tasks. This underlines the importance of distinguishing between inhibitory control concepts when examining the risks of bipolar disorder.