Reproductive Medicine, Chronobiology
and Human Ethology, ISSN 0172780X
Vol.24 Nos.3/4, Jun-Aug 2003
Reduction of night/day difference in melatonin blood levels
as a possible disease-related index in schizophrenia
of night/day difference in melatonin blood levels as a possible
disease-related index in schizophrenia
Bersani, Monica Mameli, Alessandra Garavini,
Paolo Pancheri & *Maurizio Nordio
Psychiatric Clinic, Department of Psychiatric Sciences and
Psychological Medicine, University of Rome "La Sapienza",
* Department of Medical Physiopathology, University of Rome
"La Sapienza", Rome, Italy.
November 11, 2002
Accepted: December 16, 2002
melatonin, schizophrenia, circadian rhythm, psychopathology,
Aim of this study was to verify if a simple index as night-day
plasma MLT level variation is able to confirm the existing
data on circadian melatonin alterations in schizophrenia and
if a relationship to disease itself instead of the actual
clinical state can be suggested.
and design: Ten consecutively admitted male schizophrenic
inpatients were examined.
methods: The blood samples for melatonin were collected at
3.00 a.m. and 15.00 p.m. and consequently calculated the values
of Delta () (MLT h.3.00 MLT h.15.00). We divided the
sample into two subgroups: < 30 pg/ml and > 30 pg/ml
taking 30 pg/ml as an arbitrary value, based on literature
data, that should indicate a physiologically correct value
The 70% of the sample was under the 30 pg/ml value of (13.61
± 4.0) or was lacking of the characteristic circadian
pattern of MLT secretion, whilst the 30% of the sample was
over the 30 pg/ml value of (83.60 ± 16.34) or was in
presence of the characteristic circadian pattern of MLT secretion
(p=.0001). No correlation was found between values and the
scale and subscales scores for the assessment of psychopathology.
findings: The data confirm the lack of the characteristic
circadian pattern of MLT secretion in schizophrenics.
The absence of significant correlation between night / day
melatonin level differences and actual psychopathology variables
should indicate that the suppression of is mostly related
to the disease and independent from the clinical state. A
neuroleptic-treatment effect cannot be excluded so far.
Copyright © Neuroendocrinology Letters 2003
Society of Integrated Sciences
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