What Is Depression?

Understanding Your Body

Understanding Your Body provides easy-to-understand explanations of body systems and disease conditions. This material can be used for patient education, life sciences curriculum development, or to enhance public understanding of general health concepts. Permission for such use is not required, but citation as to source is requested. The information provided is derived from Consumer Versions of Clinical Practice Guidelines, sponsored by the Agency for Health Care Policy and Research, from 1992 to 1996.

Major depressive disorder, often referred to as depression, is a common illness that can affect anyone. About 1 in 20 Americans (over 11 million people) get depressed every year. Depression affects twice as many women as men.

Depression is not just "feeling blue" or "down in the dumps." It is more than being sad or feeling grief after a loss. Depression is a medical disorder (just like diabetes, high blood pressure, or heart disease are medical disorders) that day after day affects your thoughts, feelings, physical health, and behaviors.

Symptoms include sadness, inactivity, difficulty thinking and concentrating, and feelings of despair. Depressed persons often have trouble sleeping, changes in appetite, fatigue, and agitation.

Depression may be caused by many things, including:

  • Family history and genetics.
  • Other general medical illnesses.
  • Certain medicines.
  • Drugs or alcohol.
  • Other psychiatric conditions.

Certain life conditions (such as extreme stress or grief), may bring on a depression or prevent a full recovery. In some people, depression occurs even when life is going well.

Depression is not your fault. It is not a weakness. It is a medical illness. Depression is treatable.

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Current as of November 2007
Internet Citation: What Is Depression?: Understanding Your Body. November 2007. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/patients-consumers/prevention/understanding/bodysys/edbody10.html