Depression is a common and serious medical illness that negatively affects person feeling, the way you think and how you act. Depression causes feelings of sadness and/or a loss of interest in activities once enjoyed. It can lead to a variety of emotional and physical problems and can decrease a person’s ability to function at work and at home.
Depression symptoms can vary from mild to severe and can include:
- Feeling sad or having a depressed mood
- Loss of interest or pleasure in activities once enjoyed
- Changes in appetite — weight loss or gain unrelated to dieting
- Trouble sleeping or sleeping too much
- Loss of energy or increased fatigue
- Increase in purposeless physical activity (e.g., hand-wringing or pacing) or slowed movements and speech (actions observable by others)
- Feeling worthless or guilty
- Difficulty thinking, concentrating or making decisions
- Thoughts of death or suicide
Symptoms must last at least two weeks for a diagnosis of depression.
Several factors can play a role in depression:
- Biochemistry: Differences in certain chemicals in the brain may contribute to symptoms of depression.
- Genetics: Depression can run in families. For example, if one identical twin has depression, the other has a 70 percent chance of having the illness sometime in life.
- Personality: People with low self-esteem, who are easily overwhelmed by stress, or who are generally pessimistic appear to be more likely to experience depression.
Environmental factors: Continuous exposure to violence, neglect, abuse or poverty may make some people more vulnerable to depression.