Behavioral Treatment for Nightmares in REM Sleep Behavior Disorder

Inclusion Criteria: * Diagnosis of isolated RBD or RBD secondary to neurodegenerative disease * Age 18 or older * Speak, read, and write English * Live in the United States * Nightmare frequency ≥3 times per week * Disturbing Dream and Nightmare Severity Index score indicative of nightmare disorder * Sleep, neurological, and psychiatric medications stable for at least 1 month and willing to keep medications stable through the course of the study * Live with a family member who is willing to participate in the study Exclusion Criteria: * Possible dementia * Narcolepsy * Posttraumatic stress disorder * Previous behavioral treatment for nightmares * Currently engaged in sleep- or trauma-focused psychotherapy * Taking a medication that could cause RBD, if the medication was started prior to onset of RBD symptoms Inclusion Criteria (Family Members): * Live with a family member who meets all of the above criteria * Age 18 or older * Speak, read, and write English * Live in the United States