Biological Factors for Depression
Depression is a chronic mental disorder that affects all areas of an individual’s life 1. It is characterized by extreme despair, feelings of worthlessness, persistent fatigue and/or thoughts of suicide. Approximately 10 percent of adults over the age of 18 suffer from depression in the United States each year, according to the website Healthy Place. While the exact cause of depression is unknown, it has been suggested that a combination of biological factors and environmental stressors contribute to the onset and progression of the disorder 2.
Genetics
Genetics play an important part in the development of depression. Depression tends to run in families, suggesting that it is largely hereditary. An individual is 1.5 to three times more likely to develop the condition if she has a close relative with depression than someone who does not have a family link to it, according to the website All About Depression 1. While depression may be generational for most families, it is possible to develop the disorder even if there is no family history of it.
- Genetics play an important part in the development of depression.
- An individual is 1.5 to three times more likely to develop the condition if she has a close relative with depression than someone who does not have a family link to it, according to the website All About Depression 1.
Abnormal Brain Structure and Chemistry
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Abnormal brain structure and chemistry contribute to the development of depression. The National Institute for Mental Health states that the brain structure of people with depression seems to vary slightly from people who do not have the disorder. When a person has depression, the parts of their brain responsible for regulating mood, thinking, sleep, appetite and behavior do not function normally. People who suffer from depression have an imbalance in neurotransmitters, chemicals that brain cells use to communicate, which prevents the brain from functioning effectively.
- Abnormal brain structure and chemistry contribute to the development of depression.
- People who suffer from depression have an imbalance in neurotransmitters, chemicals that brain cells use to communicate, which prevents the brain from functioning effectively.
Hormone Imbalances
There appears to be a link between depression and hormone imbalances. Depressed people appear to have an excess amount of cortisol, a hormone that regulates the body’s response to stress, anger and fear, according to Psych Central. A healthy person’s cortisol level peaks in the morning, then gradually decreases throughout the day, while a depressed person’s cortisol level peaks in the morning, but remains elevated throughout the day and night, resulting in a hormone imbalance.
In addition, certain medical conditions can affect a person’s hormonal balance and, therefore, trigger depression. Hypothyroidism, a condition in which the thyroid gland does not produce enough hormones, is also known to cause depression in some people.
- There appears to be a link between depression and hormone imbalances.
- A healthy person’s cortisol level peaks in the morning, then gradually decreases throughout the day, while a depressed person’s cortisol level peaks in the morning, but remains elevated throughout the day and night, resulting in a hormone imbalance.
Related Articles
References
- All About Depression: Genetic Causes of Depression
- Psych Central: Biological Link to Obesity and Depression
- National Institute of Mental Health. Chronic illness & mental health.
- Weissman MM, Berry OO, Warner V. A 30-year study of 3 generations at high risk and low risk for depression. JAMA Psychiatry. 2016;73(9):970-977. doi:10.1001/jamapsychiatry.2016.1586
- Ng E, Browne CJ, Samsom JN, Wong AHC. Depression and substance use comorbidity: What we have learned from animal studies. Am J Drug Alcohol Abuse. 2017;43(4):456-474. doi:10.1080/00952990.2016.1183020
- Lohoff FW. Overview of the genetics of major depressive disorder. Curr Psychiatry Rep. 2010;12(6):539-546. doi:10.1007/s11920-010-0150-6
- Yang L, Zhao Y, Wang Y, et al. The effects of psychological stress on depression. Curr Neuropharmacol. 2015;13(4):494-504. doi:10.2174/1570159x1304150831150507
- Larrieu T, Layé S. Food for mood: Relevance of nutritional omega-3 fatty acids for depression and anxiety. Front Physiol. 2018;9:1047. doi:10.3389/fphys.2018.01047
- Knüppel A, Shipley MJ, Llewellyn CH, Brunner EJ. Sugar intake from sweet food and beverages, common mental disorder and depression: Prospective findings from the Whitehall II study. Sci Rep. 2017;7(1):6287. doi:10.1038/s41598-017-05649-7
- Zisook S, Shear K. Grief and bereavement: What psychiatrists need to know. World Psychiatry. 2009;8(2):67-74. doi:10.1002/j.2051-5545.2009.tb00217.x
- Qato, DM, Ozenberger, K, Olfson, M. Prevalence of prescription medications with depression as a potential adverse effect among adults in the United States. JAMA. 2018;319(22):2289-2298. doi:10.1001/jama.2018.6741
- Aziz R, Steffens D. What are the causes of late-life depression? Psychiatric Clinics of North America. 2013;36(4):497-516.
- Wigner P, Czarny P, Galecki P, Su K-P, Sliwinski T. The molecular aspects of oxidative & nitrosative stress and the tryptophan catabolites pathway (TRYCATs) as potential causes of depression. Psychiatry Research. September 2017.
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Writer Bio
R. Y. Langham served as a senior writer for "The Herald" magazine from 1996-99. Langham holds a Bachelor of Arts in English from Fisk University, a Master of Science in marriage and family therapy from Trevecca Nazarene University and a Ph.D in family psychology from Capella University. Dr. R.Y. Langham published her first psychological thriller in September 2011. It can be purchased on Amazon.com, Barnes&Noble.com and Lulu.com.