We determined by radioimmunoassay plasma melatonin levels on blood samples drawn at 11 p.m. in migraine patients and control subjects. Ninety-three cephalalgic outpatients (75 females, 18 males) were compared to a control group (24 females, 22 males) matched according to age.
Patients were divided into subgroups presenting common migraine (n = 38); ophthalmic migraine (n = 12); and tension headache associated with ophthalmic or common migraine (n = 24), and associated depressive status (n = 19). Statistical analysis revealed a decrease in plasma melatonin levels for the entire migraine population, compared to the control one, and a heterogeneity in both controls and patients; this heterogeneity was found mainly in the depressive and tension headache subgroups.
When the migraine population-from which the depressive patients were excluded-was divided into male and female subgroups, a decrease in plasma melatonin levels was observed only for the female subgroups.
Results are discussed with reference to the role of the pineal gland in the synchronization of the organism with the environmental conditions.