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"THCâ??s effect on SWS and REM sleep stages
Several studies have examined the effect of THC on SWS and REM sleep stages. In one of the earliest studies, rats injected with THC experienced induced bursts of polyspikes (on electrocortigram) just prior to stage 1 sleep. The polyspikes appeared again, overriding totally or partially the REM sleep stages (Masur & Khazan, 1970). Fujimori & Himwich (1973) found that THC caused a decrease in the number of REM sleep episodes in rabbits. By the third day of abstinence, the REM sleep cycle of the rabbits had returned to normal. Moreton & Davis (1973) measured the effect of THC on sleep cycles for both rats that were previously deprived of REM sleep and rats not REM-deprived, finding decreased SWS and REM sleep and increased wakefulness in rats injected with THC. Deniker, Ginestat, Etevenon, & Peron-Magnon (1975) found results verifying earlier research, with the added contribution of demonstrating that THC, when isolated from cannabis, has the same effect on sleep cycles as cannabis itself. The adverse impact of THC on SWS and REM sleep was noted in cats by Fairchild, Jenden, Mickey, & Yale (1979) and again in rats by Buonamici, Young, & Khazan (1982). Freemon (1982) conducted a study using two 23 and 25-year-old brothers, who slept in a laboratory for 27 nights and, following a 4 night break, 4 additional nights. THC administration and placebo administration was provided for both brothers alternately. The subjects experienced a decrease in SWS and REM sleep, and REM sleep had returned to normal about one week after abstinence from THC. However, it should be noted that the sample size for that study was very small. While examining the suspected anticonvulsant properties of 3 different cannabinoids on rats, Colasanti, Lindamood, & Craig (1982) found that both THC and delta-8-tetrahydracannibinol reduced REM sleep."