Bipolar disorder, also known as manic depression, is a mood disorder characterised by swings in a person's mood from one extreme to another. These mood swings are characterised by ‘highs’ (feelings of extreme happiness, excitement and over-activity), ‘lows’ (intense feelings of depression, despair and hopelessness) and ‘mixed feelings’.

Bipolar disorder affects about one in 100 people. Bipolar disorder can occur at any age, although it often develops between the ages of 18 and 24. Men and women from all backgrounds are equally likely to develop bipolar disorder.

There are great variations in the pattern of mood swings. Some people have mood swings every few days. Others can have long periods without experiencing problems and many will hold down demanding jobs. However, a significant minority can be very disabled by the condition and struggle to hold down a job and cope with daily life.