Narcolepsy Nightmare Study

The goal of this clinical trial is to test two behavioral treatments for nightmares in adults with narcolepsy. The main questions it aims to answer are: * Is imagery rehearsal therapy (IRT) effective for narcolepsy-related nightmares? * Does adding targeted dream control (TDC) to IRT make it more effective? Participants will be randomized to one of two treatment groups and will be asked to: * Complete a daily log of sleep symptoms for up to 13 weeks. * Attend 7 sessions of treatment. * Complete questionnaires before and after treatment. * Go to the research lab in Evanston, IL to complete a sleep study during a daytime nap (Chicago area residents only).

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)