Narcolepsy affects about 1 in 2,000 to 3,000 people. It affects males and females equally, and symptoms usually develop in childhood or the teen years. Narcolepsy is often not diagnosed for years, or sometimes decades, after the symptoms develop. Since narcolepsy has an underlying genetic component, family members of people with narcolepsy are at a slightly increased risk of developing the disorder. However, developing narcolepsy is a complex process of genes and triggering events; therefore, many family members of a person with narcolepsy may not have it.