Mood disorders are a category of mental health problems that includes all types of depression and bipolar disorder. Mood disorders are sometimes called affective disorders. Mood disorders in children are recognized as one of the most under-diagnosed psychiatric illnesses. Mood disorders include:
- Major depression. A two-week period of a depressed or irritable mood or a noticeable decrease in interest or pleasure in usual activities along with other signs of a mood disorder.
- Dysthymic disorder (dysthymia). A chronic, low-grade, depressed or irritable mood for at least one year.
- Bipolar disorder. At least one episode of a depressed or irritable mood and at least one period of a manic (persistently elevated) mood.
- Mood disorder due to a general medical condition. Many medical illnesses (including cancer, injuries, infections and chronic medical illnesses) can trigger symptoms of depression.
- Substance induced mood disorder. Symptoms of depression that are due to the effects of medication, drug abuse, exposure to toxins or other forms of treatment.