A mood disorder involving periods of incapacitating depression alternating with manic episodes of extreme excitement. Formerly called manic depression.
A sudden, rapidly escalating emotional state characterized by extreme euphoria, excitement, physical energy, and rapid thoughts and speech.
A mood disorder characterized by extreme and persistent feelings of despondency, worthlessness, and hopelessness, causing impaired emotional, cognitive, behavioral, and physical functioning.
Cognitive (thinking) symptoms:
Causes of Mood Disorders
1. Genetics. Depression and bipolar disorder are often inherited from parents.
Low levels of neurotransmitters needed for brain activity cause depressed mood and slow activity.
Stressful Life Events are a common cause of depression.
A useful link for people interested in investigating depression:
Here's a link to a National Institutes of Health page on bipolar disorder: