MELATONIN SUPPRESSION BY LIGHT IN AFFECTIVE DISORDER

Project: Research project

Description

Affective disorder appears to be strongly influenced by genetic factors.
However, apart from recent DNA marker studies in certain families,
particular biological markers of vulnerability have yet to be confirmed.
Suppression of melatonin by light has been found to be unusually sensitive
in a small number of medications. It appears to be similarly sensitive in
some high-risk offspring of bipolars. Thus, it may be a trait marker for
certain forms of affective disorder. This work requires replication in a new population. Using a case-control
design, we propose to test melatonin suppression by light in euthymic
bipolar patients, examine its relationship to baseline melatonin rhythms on
a dark night in the same subjects, and compare light suppression in
patients to that in controls for sex, age, and season of testing. Melatonin suppression will be measured by exposing subjects to 500 lux
light between 2 A.M. and 4 A.M. and measuring plasma melatonin before and
after the light stimulus. The study will be performed on a clinical
research ward. We also propose to test reproducibility of the melatonin suppression
response in volunteers and examine the effects of lithium on suppression in
patients. A group of unipolar patients would also be tested to assess the response in
another affective subgroup. These patients will also be compared with
matched controls. Confirmation of a biologic vulnerability marker for bipolar illness and
related affective conditions would be an important step in understanding
their pathophysiology. It would also be potentially useful in genetic
counselling for patients and their families.
StatusFinished
Effective start/end date4/1/903/31/95

Funding

  • National Institutes of Health
  • National Institutes of Health: $121,961.00
  • National Institutes of Health
  • National Institutes of Health: $153,325.00

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Melatonin
Mood Disorders
Light
Inpatients
Biomarkers
Genetic Markers
Lithium
Volunteers
Population

ASJC

  • Medicine(all)