Abstract
This study aims to provide a preliminary overview of how specific sleep problems might have differential impacts on
the phenomenological properties of dreaming. The sample contained 186 upper secondary school students, whose
subjective intensity of dream experiences, thematic dream content, and sleep disturbances were assessed using the
Dream Intensity Scale, Dream Motif Scale, and Sleep Habits Questionnaire, respectively. The overall evidence suggests
that most sleep problems, except sleep bruxism, sleepwalking, and snoring, can amplify various aspects of dreaming,
with the effects of sleep paralysis being the most robust and extensive. Although both sleep onset insomnia and
hypersomnia may increase the overall intensity of dreaming, the elevated dream intensity in sleep onset insomnia is
primarily reflected by stronger dream distortion and paramnesia whereas that in hypersomnia is more contributed by
vivid perceptual sensations during dreaming.

Key words: dream themes, dream intensity, narcolepsy, sleep disorders, sleep disturbances