Effect of chronic antidepressant treatment with adinazolam and desipramine on melatonin output

Output of melatonin or its main metabolite, 6-sulphatoxy melatonin, provides an index of noradrenergic activity in the pineal gland, which is of interest in major depression and during its treatment with antidepressants. Fifteen female depressed outpatients did not differ in levels of 24-hour urinary 6-sulphatoxy melatonin compared with 13 female control subjects. However, a subgroup of the depressed patients (n = 9) who were treated with desipramine showed a significant elevation of 6-sulphatoxy melatonin levels after 1 week of treatment and a return to baseline levels after 6 weeks. There was also a significant negative correlation between 6-sulphatoxy melatonin levels and symptom severity as measured by the Hamilton Rating Scale for Depression after 3 weeks of treatment with desipramine. The other subgroup of depressed patients (n = 6) were treated with adinazolam, a benzodiazepine with antidepressant properties. Despite comparable antidepressant effects to those achieved with desipramine, adinazolam was not associated with any apparent change in 6-sulphatoxy melatonin output during 6 weeks of treatment. There was also no correlation between 6-sulphatoxy melatonin levels and symptom severity.