Suppressing REM sleep with the antidepressant clomipramine (50 mg) in 11 healthy young men did not substantially affect dream recall, including report length, complexity, bizarreness, pleasantness, or self-perception of dream or thought-like mentation. REM sleep was suppressed by a marked 81% (range 39-98%). The persistence of long, complex, and bizarre dreams even after partial or total REM suppression suggests that the generation of mental activity during sleep is independent of sleep stage.
Dream recall declines from early adulthood onward, not specifically in old age, and dream reports become less intense perceptually and emotionally. This decline occurs faster in men than women, with gender differences in dream content. Changes in lifestyle and attitude toward dreams in early adulthood partly explain the decline, but modifications of sleep physiology, especially the decrease and qualitative changes in REM sleep, are the main cause. Dreams hold little subjective importance for most older adults, though working with dreams can aid psychotherapy. Patients with degenerative dementia dream much less than healthy older adults; in Alzheimer's disease, this may relate to reduced REM sleep and atrophy of associative sensory cortex. REM sleep behavior disorders and nightmares induced by cholinesterase inhibitors are the most studied aspects of dreaming in cognitive disorders.