Narcolepsy Nightmare Study

Inclusion Criteria (all participants): * Diagnosis of narcolepsy * Age 18 or older * Speak English * Live in the United States * Receiving standard medical care for narcolepsy * Sleep and psychiatric medications stable for at least 3 months * Nightmare frequency of ≥3 times per week * Nightmare Disorder Index score indicates probable nightmare disorder Inclusion Criteria (Chicago area participants): * Able to attend a study appointment in Evanston, IL * Able and willing to not take wake-promoting medications on day of lab visit Exclusion Criteria: * History of a neurological disorder that might alter EEG * Currently engaged in sleep- or trauma-focused psychotherapy * Previous behavioral treatment for nightmares * Medical, psychiatric, or cognitive condition which would interfere with ability to engage in the treatment * Untreated sleep apnea (AHI ≥ 5)