It may be hard to believe but stress can be good for us. It forces us to stay alert and ready to react in the face of possible danger. A normal part of life, stress can come from daily annoyances to a death or loss of a job.
Many people can move past such stressful events, but for some, too much stress may lead to depression.
Depression is characterized by anxiety, persistent sadness, and loss of interest in once enjoyable activities. It also affects concentration and sleep, according to Livestrong.com.
There are two types of stress. Chronic stress lasts for an extended period of time. Acute stress is response to a traumatic event. Both types send the body's stress-response mechanism into overdrive.
Chronic stress leads to increased cortisol levels. Cortisol is called the stress hormone. Chronic stress also reduces levels of the brain’s neurotransmitters like serotonin and dopamine. Reduced dopamine levels have been linked to depression.
When our bodies are stress-free, our biological systems work normally. We sleep, eat and experience normal emotions and moods explained WebMD.com.
For some people, the body doesn’t go back to normal after a stressful event or period of time. The stress-response mechanism stays on, and can lead to depression in susceptible people.
Biology may be to blame for what happens to these susceptible people. There is "evidence showing some people have certain genetic markers that predispose depression in response to stress,” according to Dr. Ian H. Gotlib, a Stanford psychology professor, in an article published in the journal Biological Psychiatry, as reported on Livestrong.com.
Psychological issues can also play a role. People who have previously experienced depression or are currently diagnosed with depression, may be more likely to be greatly affected by stress. Additional research found that dysfunctional attitudes in daily life, feeling incredibly vulnerable, and having low self-esteem can also be a factors when linking stress to depression.
A study from Johns Hopkins University School of Medicine in Maryland looked at stress and mental illness such as depression. Researchers worked with young mice who had genetic markers for mental illness and drew parallels to how young adults may similarly be affected.
They introduced stress by keeping the mice with genetic markers for mental illness away from the other mice. The isolated mice experienced the release of cortisol, the stress hormone. Cortisol is known to affect levels of dopamine. Changes in dopamine levels have been linked to depression and other mental illnesses.
The researchers concluded that this isolation caused high levels of stress which then activated symptoms of mental illness in the mice predisposed for the psychological condition, wrote EverydayHealth.com.
A similar study in Denmark, working with rats, also discovered a possible explanation for the stress-depression link, reported ScienceNordic.com .
The rats were subjected to stressful situations over extended periods like the mice at Johns Hopkins. For example, the rats’ cages were suddenly filled with water, making it difficult for them to maintain their footing. After several similar experiences, a large number developed depression-like symptoms.
Sources:
Bruno, Karen. "The Stress-Depression Connection | Can Stress Cause Depression?" WebMD. WebMD. Web. 20 Oct. 2015.
http://www.webmd.com/depression/features/stress-depression
Hildebrandt, Sybille. "How Stress Can Cause Depression." Sciencenordic.com. Web. 20 Oct. 2015.
http://sciencenordic.com/how-stress-can-cause-depression
Iliades, MD, Chris. "Stress May Trigger Mental Illness and Depression In Teens." EverydayHealth.com. Web. 20 Oct. 2015.
http://www.everydayhealth.com/depression/stress-may-trigger-mental-illness-and-depression-in-teens.aspx
Moore, Ayra. "How Does Stress Lead to Depression?" LIVESTRONG.COM. LIVESTRONG.COM, 21 Jan. 2014. Web. 20 Oct. 2015.
http://www.livestrong.com/article/18230-stress-lead-depression
Reported October 22, 2015
by Michele Blacksberg RN
Edited by Jody Smith