The pineal hormone melatonin in panic disorder.

The nocturnal synthesis of the pineal hormone melatonin was examined from 8 p.m. to midnight in 11 patients with panic disorder and eight control subjects. Patient concentrations of melatonin were significantly lower than controls at 10 p.m. (P less than 0.05; Kruskal-Wallis one-way ANOVA) and midnight (P less than 0.01). At 9 p.m. and 11 p.m., patient concentrations were also lower than controls, but were not statistically significantly different (P = 0.09). From these data, it is postulated that some patients with panic disorder exhibit a generalised defect in sensitivity of beta-adrenergic receptors or of sympathetic transmission.