5 Newer Theories on the Cause of Depression

depression-brainI grew up thinking depression was as simple as one little transmitter getting lost somewhere on his way from one neuron to the other, much like I do when I venture further than five miles from home. It’s an easy explanation–a chemical imbalance in the brain–one that pharmaceutical companies have adopted to craft creative commercials like the Zoloft egg not chasing the butterfly.

But depression is so much more complex than that. Here are a few other plausible causes of depression that have surfaced from recent studies:

1. Faulty Brain Wiring

When experts scanned the brains of depressed people, they discovered that the frontal lobes of the brain, the part associated with higher cognitive processes, displayed lower activity levels than those in non-depressed patients. Other brain imagining reveals breakdown in normal patterns of emotional processing that impedes the ability of depressed patients to suppress negative emotional states. High levels of activity in the amygdala part of the brain, the fear center, persisted despite cognitive efforts to retrain the thoughts. Depression, then, involves a problem in the wiring pattern in the brain: not a single brain activity pattern, but by a brain activity pattern that is unique to each person.

2. Brain Atrophy

Depression can be associated with the loss of volume in parts of the brain, namely the hippocampus, which belongs to the limbic system (the emotional center of the brain), and is important in the consolidation of information from short-term memory to long-term memory. The more severe the depression, the greater the loss of brain volume. The atrophy affects the brain’s frontal lobes, as well, especially the prefrontal cortex, which regulates the emotional centers of the brain. Finally, depression appears to inhibit the birth of new brain cells, or neurogenesis. For this reason, Peter Kramer, M.D. believes that depression is the “most devastating disease known to mankind.”

3. Hormonal Imbalances

The endocrine system may also play a role in depression. Some studies have indicated a default in the hypothalamic-pituitary-adrenal (HPA) axis, the region that manages the body’s response to stress. When a person is in distress, the hypothalamus produces corticotropin-releasing factor (CRF) and other substances that stimulate the pituitary gland to release stress hormones that send a flight-or-fight response. Chronic activation of the HPA can contribute to depression.

4. Genetics

There are many genetic variations than can increase a person’s vulnerability to depression and other mood disorders, although some of these variations have yet to be identified. Scientists have identified a gene that may be linked to bipolar disorder, and experts have also found a common genetic mutation associated with a person developing clinical depression when faced with traumatic events in his or her life. A study on twins showed that if one twin developed depression, the other twin also suffered from depression in 46 percent of identical twins, compared with 20 percent of fraternal twins.

5. Brain Inflammation

In his bestseller, Grain Brain, renowned neurologist David Perlmutter, M.D. explains that the cornerstone of all degenerative conditions—including depression, anxiety, and bipolar disorder—is inflammation, and the most prominent stimulators of inflammation in our diet are gluten and sugar. We get into trouble because we can’t feel the inflammation in our brain like we can in other parts of the body, so we rarely link a kind of food we eat with our mood. Perlmutter points out that study after study demonstrates that people who suffer from mood disorders also tend to be gluten-sensitive and vice versa: depression is found in as many as 52 percent of gluten-sensitive individuals.

Image: Health.Harvard.edu

Published originally on “Sanity Break” at EverydayHealth.com.

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6 thoughts on “5 Newer Theories on the Cause of Depression

  1. This is very informative, and interesting. Always willing to learn.
    These facts should make us feel proud that we function as well as we do – even when we think we can’t get out of bed, etc.

    Hugs to a great lady,

  2. I greatly appreciate this article. It’s a sad fact: I am must research and figure out how to care for myself. In spite of being under the care of multiple doctors. All seem to micromanage their own specialty incrementally to the point that I don’t want to continue life. I have had a chronic severe migraine for going on 17 months now, its very unpopular co-partner chronic insomnia and their trailing cousin depression.

    It’s hard to stay positive when your brain is constantly irritated, your stomach nauseated, you can’t sleep in-spite of various medication trials. There simply isn’t enough meditation, self centering, prayer to overcoming the drowning symptoms that no one will address (seemingly).

    Please understand tests have been run MRI (Multiple) MRV, recently a MRA supposively revealed a aneurysm only to be told after two CAT scans and a lumbar puncture not so (done by a resident at our local ER) followed by a severe headache and need for a second ER visit for a blood patch.

    I have seen a therapist for better than two years….was told by both she my neurologist when I disclosed my hopelessness and lack of desire to continue life to ask for treatment when I was seen. When I did I was told “that was an improper use of the ER” no offer for referral or other source of treatment.

    Sadly only one in five will ever have the courage to ask for help, when you do it is like hitting a brick wall. Realizing all the messages of “hope and help out there” is not usually true.

    Humans will fall over backwards to help you when you have a broken or injured limb. Have a broken brain and good luck trying to find any real sustainable treatment!

    1. Leisa, I am sorry what you have had to go through. Is it possible you can speak to your family openly what you are going through? I would have loved to have helped my child find the right help. She has chosen to cut me off. As an adult in the US I am unable to help her.

      Shanti

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