Dreaming in patients with sleep disorders: A multicenter study

Dreaming is defined as a subjective experience, while sleeping is obviously closely related to sleep physiology. The present multicenter study (n=4,001 patients) was designed to test whether differences in sleep physiology and daytime functioning, present in patients with sleep disorders, affect the dreaming process. Overall, patients with sleep disorders reported higher dream recall, more nightmares, and more negatively toned dreams. Whereas the differences in dream recall are most likely associated with altered sleep physiology (more frequent nocturnal awakenings and/or micro-arousals), the findings regarding nightmare frequency and dream emotions might reflect the distress associated with the sleep disorder. Desirable would be longitudinal studies; it would be expected that successful treatment should alter nightmare frequency and dream emotions in patients with insomnia, restless legs syndrome/periodic limb movement disorders, and other sleep disorders. Whether dream content reflects disorder-specific content in addition to general distress remains unanswered.