Decision‐making impairment under ambiguity but not under risk may underlie medication overuse in patients with chronic migraine

Objective To explore whether patients with chronic migraine and medication overuse headache (CM + MOH) present with decision‐making deficit. Background Factors underlying MOH in patients with CM remain unclear. Whether the process of decision‐making plays a role in MOH is still controversial. Decision‐making varies in the degree of uncertainty: under ambiguity where the probability of outcome is unknown, and under risk where probabilities are known. Methods Decisions under ambiguity and risk were assessed with the Iowa Gambling Task and the Cambridge Gambling Task, respectively, whereas executive function was assessed by the Wisconsin Card Sorting Test. Results A total of 75 participants: 25 patients with CM + MOH, 25 with CM, and 25 age‐ and sex‐similar healthy controls (HCs), completed this cross‐sectional study. There was no significant difference in headache profiles except for more frequent analgesic use (mean ± SD: 23.5 ± 7.6 vs. 6.8 ± 3.4 days; p