The authors investigated the melatonin response to 5-methoxypsoralen in
39 healthy adult and elderly subjects and in 13 demented, 13 depressed, and
13 schizophrenic inpatients. Subjects' plasma melatonin levels were
evaluated before they took single, oral 40-mg doses of 5- methoxypsoralen
and 3 hours afterward. The preliminary results indicate that the melatonin
response of the pineal gland to 5-methoxypsoralen is reduced in demented
patients compared to that in healthy elderly subjects. Depressed and
schizophrenic patients had a normal melatonin response to the drug. This
finding suggests that the pineal gland may be functionally impaired in
dementia but not in depression.Abstract Teaser