TORONTO, June 4, 2014 /CNW/ - 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 perimenopause.
"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 41-51.
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-A levels 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 in menopause.
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
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.
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.
SOURCE: Centre for Addiction and Mental Health
For further information:
Centre for Addiction and Mental Health (CAMH)
416 535 8501 x36015