We all have our dark days, but depression isn’t about being frustrated with minor setbacks that may occur when you don’t get your way. Symptoms of major depressive disorder (MDD) significantly interfere with everyday activities, work and personal lives.
According to the Depression and Bipolar Support Alliance, approximately 14.8 million American adults, or 6.7 percent of the United States population over age 18, are affected by MDD every year. Depression can last anywhere from a few days to a few years, but longer-lasting and intense forms of depression may display five or more of the following symptoms at least once a day over the course of two weeks:
- Feelings of sadness, emptiness, hopelessness
- Lack of interest in things and activities you once enjoyed
- Decrease or increase in appetite accompanied by weight loss or weight gain
- Sleeping too much/too little
- Difficulty concentrating
- Thoughts of suicide or attempts of suicide
- Excessive feelings of guilt or worthlessness
Three parts of the brain that appear to play a role in MDD are the hippocampus (which stores memories and regulates the production of stress hormone, cortisol), amygdala (which facilitates emotional responses), and prefrontal cortex (which regulates emotions and forms decisions). Here are the following long-term effects on the brain when MDD goes untreated.
During normal times of physical and mental stress, the body releases cortisol, which works with your brain to control your mood, motivation, and fear. In depression, excessive amounts of cortisol are released and the long-term exposure to these levels can slow the production of new neurons, causing the hippocampus to shrink. As a result, memories are blurred, and at times altered.
Disturbances in sleep
In response to the constant high exposure to cortisol, the amygdala becomes enlarged and more active. It can also cause the body to release an excess of other hormones and chemicals, making it hard to get a good night’s rest.
On the flip side, people who suffer from MDD experience a shrinkage in the prefrontal cortex. This can result in trouble thinking, concentrating, making decisions, planning or setting priorities.
May lead to neurodegenerative diseases
For our bodies, the right amount of inflammation protects us from disease and repairs us when injured. Years of untreated depression may lead to significantly more inflammation in the brain which “is a common response with degenerative brain diseases as they progress, such as with Alzheimer’s disease and Parkinson’s disease,” says Dr. Jeff Meyer of the Centre for Addiction and Mental Health (CAMH) at the University of Toronto.