BackgroundStudies addressing relapse rates conflate relapse into chronic migraine (CM) and medication overuse (MO), and the consequent need to repeat withdrawal. We aim to identify 12-months predictors of relapse into CM (based on headaches frequency) separately from occurrence of another structured withdrawal. MethodsHospitalized patients with CM-MO under withdrawal were enrolled. Candidate predictors included demographic, disability, quality of life, depression scores, general self-efficacy, social support, headaches frequency and intensity, class of overused medications, history of withdrawal treatment in the three years prior to enrollment, attendance to emergency room (ER) between enrollment and follow-up, nonattendance to outpatient neurological examinations. Logistic regressions was used to address the significant predictors for the two outcomes. ResultsComplete data were available for 177 patients: 60 (33.9%) relapsed into CM, 38 (21.5%) underwent another withdrawal treatment. Recent history of withdrawal treatments, ER admission after discharge and high baseline BDI-II scores were significant predictors in both models. In addition to this, high baseline headache frequency predicted relapse into another withdrawal treatment. ConclusionsPredictors or relapse into CM and of occurrence of another withdrawal by 12-months are somehow similar. It is important to assess presence of recent previous withdrawal treatments and to plan regular follow-up afterwards, in particular for patients with high headache frequency and relevant mood disturbances: in this way, it will be more likely that situations requiring further structured withdrawal treatments can be identified before patients have to refer to ER.