Prevalence: 1-2% of the population
- however if brief or low-level hypomanic symptoms are included as diagnostic features, then some researchers quote a prevalence rate of 5-6%.
- recent research suggests that Bipolar Disorder may begin in childhood (and be mistaken for Conduct Disorder or ADHD) and may affect up to 0.5% of children under age 18.
Gender: male : female =1:1
Median age of onset: 21 years