When Do Symptoms Appear?
In most cases, symptoms first appear when people are between the ages of 10 and 25 but Narcolepsy can become clinically apparent at virtually any age. Many patients first experience symptoms between the ages of 35 and 45. A smaller number initially manifest the disorder around the ages of 50 to 55. Narcolepsy can also develop early in life, probably more frequently than is generally recognized. For example, 3-year-old children have been diagnosed with the disorder. Whatever the age of onset, patients find that the symptoms tend to get worse over the two to three decades after the first symptoms appear. Many older patients find that some daytime symptoms decrease in severity after age 60.

Narcoleptic symptoms, especially EDS, often prove more severe when the disorder develops early in life rather than during the adult years. Experts have also begun to recognize that narcolepsy sometimes contributes to certain childhood behavioral problems, such as attention-deficit Hyperactivity disorder, and must be addressed before the behavioral problem can be resolved. If left undiagnosed and untreated, narcolepsy can pose special problems for children and adolescents, interfering with their psychological, social, and cognitive development and undermining their ability to succeed at school. For some young people, feelings of low self-esteem due to poor academic performance may persist into adulthood.