Featured Research

from universities, journals, and other organizations

Most antidepressants miss key target of clinical depression, study finds

Date:
December 9, 2009
Source:
Centre for Addiction and Mental Health
Summary:
Most current antidepressants do not address a key brain chemical, monoamine oxidase-A, according to a new study.

A key brain protein called monoamine oxidase A (MAO-A) -- is highly elevated during clinical depression yet is unaffected by treatment with commonly used antidepressants, according to an important study published in the Archives of General Psychiatry. The study has important implications for our understanding of why antidepressants don't always work.

Researchers at the Centre for Addiction and Mental Health (CAMH) used an advanced brain imaging method to measure levels of the brain protein MAO-A. MAO-A digests multiple brain chemicals, including serotonin, that help maintain healthy mood. High MAO-A levels excessively remove these brain chemicals.

Antidepressant medications are the most commonly prescribed treatments in North America, yet 50 per cent of people do not respond adequately to antidepressant treatment. Dr. Jeffrey Meyer the lead investigator explains, "Mismatches between treatment and disease are important for understanding why treatments don't always work. Rather than reversing the problem of MAO-A breaking down several chemicals, most antidepressants only raise serotonin."

Understanding the Problem of a Persistent Illness

Depression ranks as the fourth leading cause of disability and premature death worldwide, according to the World Health Organization. Recurrent illness is a major problem. Even under the most optimal treatment circumstances, recurrence rates for clinical depression are at least 20 per cent over two years.

The new study also focused upon people who had fully recovered from past episodes of clinical depression. Some people who appeared to be in recovery actually had high levels of MAO-A. Those with high levels of MAO-A then had subsequent recurrence of their depressive episodes.

This new idea of high levels of MAO-A lowering brain chemicals (called monoamines), then falling into a clinical depression is consistent with the historical finding that medications which artificially lower monoamines can lead to clinical depression as a side effect. In the 1950's some medications to treat high blood pressure also lowered monoamines and people began to experience depressive episodes. When the medications were removed, people recovered.

From Technology to Treatment

VP of Research Dr. Bruce Pollock highlights the study's use of advanced brain imaging technology. "CAMH has the only positron emission tomography (PET) centre in the world that is dedicated solely to mental health and addiction treatment and research. As a consequence, we were able to develop this new technology to measure MAO-A levels."

Virginia Wilson knows first-hand the struggle it can be to find effective medication. After being diagnosed with depression, eight years passed before a medication was developed that worked well for her. "During this time I was on every type of antidepressant available. This process was enormously frustrating, painful -- and took a great toll on my personal life." The current research into depression gives Virginia hope for others who struggle as she did. "Understanding of the biochemical mechanisms behind depression is so important and can really improve the treatments that are available -- it can save lives."

Some early antidepressant medications did target MAO-A, but these MAO-A inhibitors fell out of favour in the 1970s due to adverse interactions with certain foods. There have been advances that overcome these problems, but the vast majority of antidepressant development and use has overlooked the MAO-A target.

According to Dr. Meyer, "Since most antidepressants miss MAO-A, we are counting on the brain to heal this process of making too much MAO-A, and that doesn't always happen. The future is to make treatments that tell the brain to make less MAO-A, even after the antidepressant treatment is over, to create better opportunities for sustained recovery."

Dr. Meyer is a Canada Research Chair in the Neurochemistry of Depression and the Head of the Neurochemical Imaging Program in Mood Disorders. The study was funded by the Canadian Institutes of Health Research, the Ontario Mental Health Foundation, and the Canadian Foundation for Innovation.


Story Source:

The above story is based on materials provided by Centre for Addiction and Mental Health. Note: Materials may be edited for content and length.


Journal Reference:

  1. Meyer et al. Brain Monoamine Oxidase A Binding in Major Depressive Disorder: Relationship to Selective Serotonin Reuptake Inhibitor Treatment, Recovery, and Recurrence. Archives of General Psychiatry, 2009; 66 (12): 1304 DOI: 10.1001/archgenpsychiatry.2009.156

Cite This Page:

Centre for Addiction and Mental Health. "Most antidepressants miss key target of clinical depression, study finds." ScienceDaily. ScienceDaily, 9 December 2009. <www.sciencedaily.com/releases/2009/12/091208132724.htm>.
Centre for Addiction and Mental Health. (2009, December 9). Most antidepressants miss key target of clinical depression, study finds. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2009/12/091208132724.htm
Centre for Addiction and Mental Health. "Most antidepressants miss key target of clinical depression, study finds." ScienceDaily. www.sciencedaily.com/releases/2009/12/091208132724.htm (accessed September 21, 2014).

Share This



More Mind & Brain News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Food Addiction Might Be Caused By PTSD

Food Addiction Might Be Caused By PTSD

Newsy (Sep. 18, 2014) New research shows that women who suffer from PTSD are three times more likely to develop a food addiction. Video provided by Newsy
Powered by NewsLook.com
Corporal Punishment on Decline, Debate Renews

Corporal Punishment on Decline, Debate Renews

AP (Sep. 16, 2014) Corporal punishment in the United States is on the decline, but there is renewed debate over its use after Minnesota Vikings running back Adrian Peterson was charged with child abuse. (Sept. 16) Video provided by AP
Powered by NewsLook.com
FDA Eyes Skin Shocks Used at Mass. School

FDA Eyes Skin Shocks Used at Mass. School

AP (Sep. 15, 2014) The FDA is considering whether to ban devices used by the Judge Rotenberg Educational Center in Canton, Massachusetts, the only place in the country known to use electrical skin shocks as aversive conditioning for aggressive patients. (Sept. 15) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins