Cortisol, sometimes referred to as "the stress hormone," plays an important role in what's known as the "fight or flight" response. Major depression is a leading cause of disability in the United States, according to the National Institutes of Mental Health. The link between depression and cortisol has become better understood in recent decades.
Function of Cortisol
Cortisol--a glucocorticoid hormone--is essential to the human brain's functioning. Produced by the adrenal glands, cortisol's purpose is to help cells create energy from food. When a body experiences stress, whether physical, mental, or emotional, more cortisol is created by the adrenals in order to protect the body. This charge of cortisol is part of what's known as the "fight or flight" response, which occurs when a body prepares itself to handle a stressful event. This response is key to a person's ability to act quickly in an emergency.
History
Drs. Paul Mackin and Allan Young in their 2004 article in Psychiatric Times, "The Role of Cortisol and Depression: Exploring New Opportunities for Treatments," report abnormal cortisol levels were first observed in depressed patients in the late 1950s. Connections between endocrine (hormonal system) function and mental health have been explored thoroughly for decades. As understanding of the endocrine system has advanced alongside neurocognitive research, the causes and potential treatments for mental illness have become more clear. Because glucocorticoids, the family of hormones to which cortisol belongs, are key to the body's stress response and stressful events factor heavily in the presence of mental illness, causal connections appear inevitable.
Conflicting Conclusions
Research has leaned toward a connection between cortisol levels and depression for years, but studies continue to both contradict each other and add to current understanding.
Rather than an "on-off" causation effect, studies continue to allude to a broad middle ground of impact between cortisol levels and depression. Balanced hormone levels, particularly in regard to quantity and timing, seem to be the key to mental health.
Theories About Connecting Cortisol and Depression
Dr. Sophie Vreeburg and a team from the Netherlands published research in June 2009 in "Archives of General Psychiatry" concluding that their study of more than 1,500 subjects showed a possible increased biological propensity for depression when higher cortisol awakening responses were observed. However, the "cortisol awakening response" is only one way to measure cortisol levels, and one that is very specific to the particular event--awakening. In other studies, raised cortisol levels are determined to be protective.
For example, one of the authors of a study published in "Archives of General Psychiatry" in October 2007 postulated that an "anticipatory increase in cortisol" may have evolved in humans as a chemical red flag to heighten attention. In their study, researcher Daniel S. Pine, M.D. and colleagues describe a "normal increase in cortisol" as reflective of low risk for the future development of antisocial behavior. Again, though, balance is the issue.
Dr. Jing Du's research team concluded not only that cortisol is necessary for coping, but that chronically elevated glucocorticoids, as can occur in ongoing stressful situations, work against the body at a cellular level. Their article posits that this chronic stress-related cell damage "may be at the root" of some physical and mental illness.
Promoting Mental Health
The research of Laurie Brotman, Ph.D. and Dr. Daniel Pine, which looked at cortisol response in socially challenged preschoolers, found that behavioral intervention in the form of preparation for a stressful event could alter a child's neurobiological system, making them better able to adapt to stress.
A stress response that is "always on" will eventually promote wear and tear on a body. MayoClinic.com recommends examining how you react to stress and learning to make health-promoting choices from among several stress management strategies.
References
- National Institutes of Mental Health: The Numbers Count, Mental Disorders in America
- NIMH Science Update: Research Shows How Chronic Stress May be Linked to Physical and Mental Ailments
- Psychiatric Times: The Role of Cortisol and Depression: Exploring New Opportunities for Treatments
- rchives of General Psychiatry: Major Depressive Disorder and Hypothalamic-Pituitary-Adrenal Axis Activity
- NIMH Science Update: Behavioral Intervention Normalizes Stress-related Hormone in High-Risk Kids
