June 4, 2014 (Toronto) – Women nearing
menopause have higher levels of a brain protein linked to depression than both
younger and menopausal women, a new study by the Centre for Addiction and Mental
Health (CAMH) shows.
This finding may explain the high rates of first-time
depression seen among women in this transitional stage of life, known as
Dr. Jeffrey Meyer, Senior Scientist at CAMH’s Campbell Family Mental Health Research Institute.
“This is the first time that a biological change in the
brain has been identified in perimenopause which is also associated with clinical
depression,” says Senior Scientist Dr. Jeffrey Meyer of CAMH’s Campbell Family
Mental Health Research Institute. Specifically, Dr. Meyer’s research team found
elevated levels of the chemical monoamine oxidase-A (MAO-A) among women aged
The study was published today in JAMA Psychiatry.
During perimenopause, a common symptom is mood changes such
as crying. Rates of first-time clinical depression among this group reach 16 to
17 per cent, and a similar number get milder depressive symptoms.
MAO-A is an enzyme that is a pro-oxidant and breaks down
brain chemicals such as serotonin, norepinephrine and dopamine, which help to
maintain normal mood. Dr. Meyer has previously linked high levels of MAO-A to
major depressive disorder, depressed mood related to alcohol dependence
and smoking cessation, and the period immediately after childbirth.
To investigate if MAO-Alevels may explain the mood changes
during perimenopause, his research team conducted brain scans of three groups
of women using a brain imaging technique called positron emission tomography
(PET) in CAMH’s Research Imaging Centre. Among the three groups of women, 19
were of reproductive age, 27 were in perimenopause, and 12 were in menopause.
On average, levels of MAO-A were 34 per cent higher in women
with perimenopause than in the younger women, and 16 per cent higher than those
The women in perimenopause also reported a higher tendency
to cry, based on a questionnaire called the Adult Crying Inventory, and this was
associated with high MAO-A levels in the front part of the brain, the
prefrontal cortex. The researchers had also predicted that MAO-A levels would
drop during menopause, once fluctuating levels of estrogen stabilized, and this
also proved to be the case.
The results suggest new opportunities for prevention, says
Dr. Meyer, who holds a Canada Research Chair in the Neurochemistry of Major
“Using PET imaging, we can test treatments to see if they can
prevent this elevation of MAO-A, and potentially prevent clinical depression,”
he says. One approach may be a dietary supplement, which he is currently
investigating in another study of women after childbirth, to prevent post-partum
depression.Another approach may be to offer hormone replacement therapy (HRT) at
an earlier stage to prevent the fluctuation of estrogen levels, which is also
linked to higher amounts of MAO-A.
First author of the study was post-doctoral fellow Dr.
Vivien Rekkas. This research was supported by the Canadian Institutes of Health
Research, the Brain and Behavior Research Foundation, the Canada Foundation for
Innovation and the Ministry of Research and Innovation.
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The Centre for Addiction and Mental Health (CAMH) is Canada's largest
mental health and addiction teaching hospital, as well as one of the world's
leading research centres in its field. CAMH combines clinical care, research,
education, policy development and health promotion to help transform the lives
of people affected by mental health and addiction issues. CAMH is fully
affiliated with the University of Toronto, and is a Pan American Health
Organization/World Health Organization Collaborating Centre. For
more information, please visit www.camh.ca.
Centre for Addiction and Mental Health (CAMH)
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