Depression ranges in seriousness from mild, temporary episodes of sadness to severe, persistent depression. Doctors use the term "clinical depression" to describe the more severe form of depression also known as "major depression" or "major depressive disorder."
For a diagnosis of clinical depression, you must meet the symptom criteria spelled out in the Diagnostic and Statistical Manual of Mental Disorders (DSM). The DSM is a guidebook used to diagnose mental illness in the United States.
Clinical depression symptoms may include:
- Depressed mood most of the day, nearly every day
- Loss of interest or pleasure in most activities
- Significant weight loss or gain
- Sleeping too much or not being able to sleep nearly every day
- Slowed thinking or movement that others can see
- Fatigue or low energy nearly every day
- Feelings of worthlessness or inappropriate guilt
- Loss of concentration or indecisiveness
- Recurring thoughts of death or suicide
To meet the criteria for clinical depression (called major depression in the DSM), you must have five or more of the above symptoms over a two-week period. At least one of the symptoms must be either a depressed mood or a loss of interest or pleasure. Keep in mind, some types of depression may not fit this strict definition.
Clinical depression causes noticeable disruptions in daily life, such as work, school or social activities. It can affect people of any age or sex, including children. It isn't the same as depression caused by a loss (such as the death of a loved one), substance abuse or a medical condition such as a thyroid disorder.
Clinical depression symptoms usually improve with psychological counseling, antidepressant medications or a combination of the two. Even severe depression symptoms usually improve with treatment.