Dream suppression is a decrease in the vividness, intensity, frequency, and recollection of a person's dreams. At its lower levels, this can be a partial suppression which results in the person having dreams of a lesser intensity and a lower rate of frequency. However, at its higher levels, this can be a complete suppression which results in the person not experiencing any dreams at all.
Dream suppression is most commonly induced under the influence of moderate dosages of cannabinoids  and most types of antidepressants    . This is due to the way in which they increase REM latency, decrease REM sleep, reduce total sleep time and efficiency, and increase wakefulness.     REM sleep is where majority of dreams occur. 
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