Previous research indicated that the prevalence of frequent nightmares and/or the presence of a nightmare disorder is quite high in patients with mental disorders. In the present study, 75 randomly selected psychiatric inpatients were interviewed and completed questionnaires regarding nightmares, sleep, and psychopathology. The percentage of patients with nightmares once per week or more often was 61.54% in the group with PTSD diagnosis (N = 13) and 40.32% in the patients without PTSD …