• An estimated 1-3% of the general population has bipolar disorder.
• Bipolar disorder affects males and females at equal rates.
• The peak age of onset of bipolar disorder is between the ages of 15 and 25.
• Emil Kraeplin found that the average period of feeling 'well' after a mood episode is:
• 4.3 years after the 1st episode
• 2.8 years after the 2nd episode
• 1.8 years after the 3rd episode
• 1.7 years after the 4th episode
• 1.5 years after the 5th episode
• Some professionals recommend considering 5 factors for a diagnosis of bipolar disorder:
• Age of onset
• Course of symptoms
• Family history
• Response to treatment
• Current signs and symptom

Source: ManicDepressive.org