Sleep and wakefulness are both parts of a normal daily rhythm. Fish, cats, humans, and many other living things have daily cycles of activity and rest. This daily cycle is called a circadian rhythm. "Circadian" comes from the Latin root "circa dies" and means "about a day." Both external and internal events can influence circadian rhythms. Morning light and alarm clocks trigger wakefulness. When isolated from normal time cues, the daily human cycle is about 24 hours, hence "circa dies."
The study of sleep is fascinating. Sleep has been extensively studied in research laboratories, like the University of Chicago, by measuring brain waves and eye movements while research subjects sleep. Gentle electrodes are placed on volunteers' scalps and near their eyes. While sleeping, the electroencephalogram (EEG) provides evidence of brain activity.
Though sleep seems like a passive state to us, the brain is still very active. In fact, the EEG of a person falling asleep shows five stages of sleep: Stages 1 through 4 and a stage called rapid eye movement (REM) sleep. Each stage is progressively deeper and the complete cycle is repeated several times during the night. When awakened during REM sleep, subjects report dreaming. So if dreams take place during REM sleep, the question for us is: Does smoking marijuana interrupt REM sleep?
To address this question, Feinberg, et al. (1975) compared the sleep patterns of experienced marijuana users on tetrahydrocannabinol (THC) and a placebo. Feinberg, et al. (1975) reported reduced eye movement activity and less REM sleep in the THC condition. They also reported a REM rebound effect, that is more REM activity, on withdrawal from THC. So,there exists some scientific evidence that marijuana interferes with REM sleep.
If sleep is fascinating, dreaming is even more so. No one knows for sure the meaning or function of night-time dreams, but there is plenty of speculation. Freud believed dreams represented the royal road to the unconscious. They told us our secret desires and fears.
In his book Memories, Dreams, and Reflections, Jung describes some fascinating dreams of his own. In particular, he describes one dream that haunted him for a very long time. When he was about three-years-old, he dreamed he was in a large meadow. In this meadow, there was a big dark hole. Slowly and cautiously, he descended this dark hole. At the bottom, he found a richly decorated king's throne and on the throne was a huge fleshy object. This thing was about 10 to 15 feet high and came to head but had no face. At the very top was a large eye gazing upward. During the dream, he heard his mother's voice saying that this was a maneater. The 3-year-old Jung, awoke terrified and dripping in sweat. This dream preoccupied him for years. Much later he came to understand the dream as a symbol of a giant phallus and the beginning of his theory of archetypes.
I must confess I have never been visited by a giant phallus during the night, but I have had some pretty cool dreams. During a period of intense anxiety, I was obsessed with death. One night I dreamed I was sitting in a movie theater impatiently waiting for the movie to begin. My father and my brother were next to me and I was facing the big white screen, waiting and waiting. Finally, the picture began and I was flooded with profound white light and overwhelming love. Death had come for me but death was not scary, but extremly benevolent, loving and blissful. How about you? Any night time dreams you'd like to share? Any thoughts on marijuana and dreams?
Feinberg, I., Jones, R, Walker JM, Cavness, C, March, J. (1975). Effects of high dosage delta-9-tetrahydrocannabinol on sleep patterns in man. Clin Parmacol Ther. 1975; 17(4):458-66.