Munksgaard SB, et al. - As Medication-Overuse Headache (MOH) often has migraine features and can mimic chronic migraine, researchers investigated if like migraine patients, MOH patients display lower serum levels of nociceptin and higher calcitonin gene-related peptide (CGRP) serum levels compared with those observed in healthy volunteers and if their serum levels normalize after detoxification. They analyzed 17 MOH patients, hereof 70.6% with chronic migraine and MOH, and 30 sex and age matched headache-free controls. In contrast to migraine patients, MOH patients had normal serum levels of nociceptin and CGRP, yielding no evidence that the increased headache frequency of MOH patients could be caused by altered nociceptin and CGRP levels. This underscores the significance of recognizing medication overuse in chronic headache and treating the MOH.