Depression can affect anyone — even a person who appears to live in relatively ideal circumstances. According to the American Psychiatric Association (APA), 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.
Depression is among the most treatable of mental disorders. Between 80 percent and 90 percent of people with depression eventually respond well to treatment. Almost all patients gain some relief from their symptoms.
Before a diagnosis or treatment, a health professional should conduct a thorough diagnostic evaluation, including an interview and possibly a physical examination. In some cases, a blood test might be done to make sure the depression is not due to a medical condition like a thyroid problem. The evaluation is to identify specific symptoms, medical and family history, cultural factors and environmental factors to arrive at a diagnosis and plan a course of action.