Interestingly, given the role of BDNF in psychiatric disorders (Wang et al., 2022), our findings might pave the way for a better comprehension of the molecular mechanisms underlying comorbid psychiatric disorders including mood disorder, social phobia, obsessive-compulsive disorder and substance use disorder (Jagielska and Kacperska, 2017) that persist beyond recovery from AN (Braun et al., 1994; Herzog et al., 1996; Marucci et al., 2018) and that might be linked to poor outcome in patients. This evidence concerns the gene BDNF and obsessive-compulsive disorder.