BDNF and migraine disorder: For instance, research on migraine pain has yielded mixed results, with some studies reporting lower serum BDNF levels during acute and chronic migraine (Blandini et al. 2006; Mozafarihashjin et al. 2022), while others show higher BDNF levels during headache attacks compared to attack‐free periods (Holmuratova et al. 2023).