The mood or affective disorders are mental disorders that primarily affect mood and interfere with the activities of daily living. Usually it includes major depressive disorder (MDD) and bipolar disorder (also called Manic Depressive Psychosis).

Mood disorders include, but are not limited to, the following:

• Major Depressive Disorder (otherwise known as MDD, major depression, or simply depression). This disorder can also exist with psychotic features.
• Bipolar disorder, also called bipolar. Bipolar disorder exists as a spectrum of disorders, and can include the following:
  • Bipolar I (episodes of depression, and episodes of mania with psychosis)
  • Bipolar II (episodes of depression and hypomania)
  • Cyclothymia (episodes of dysthymia and hypomania).
• Dysthymic Disorder, also called dysthymia.
• Post-partum depression. This is the sudden depression which can sometimes occur in a mother after giving birth to a child.
• Seasonal affective disorder, also known as SAD. People with this disorder experience depression during the winter months, and may require antidepressants during this time. Another therapy available for use in people with SAD is light therapy.
• Schizoaffective disorder, in which the sufferer has experienced the symptoms of schizophrenia as well as symptoms of a mood disorder.