In the last two articles we discussed the role in which THC and the CB1 cannabinoid receptors present in your body can extend sleep and solve certain sleep disorders. You may have noticed that so far the discussion of CBD has been absent. That is because CBD is thought to have virtually the opposite effect of THC, in that it is thought to increase wakefulness. Although some conditions only require medication at night, many conditions benefit from dosing throughout the day, such as chronic pain and neurological imbalances. As a result, Cornerstone members often pose the question of which strain to medicate with in situations where they need to feel alert and awake. For this reason, discovering the exact effect of CBD is important to the future of medical cannabis. Unfortunately, at this point in time, the evidence is not quite as resounding as that of THC and sleep, and while the basic hypothesis that CBD increases wakefulness has been supported numerous times, the issue has not been fully proved from a scientific standpoint.
Today, we’ll dive in to a series of reports on CBD in regards to sleep and wakefulness. These come courtesy of the University of Campeche and the National Autonomous University of Mexico, which teamed with well-known Israeli cannabis researcher Raphael Mechoulam. In the first study, researchers began by implanting EEG monitors in the brains of rodents. These allowed them to use electrical signals to know what phases of sleep rodents were in, as well as make measurements in the strength of each stage. Next, rodents were allowed to adjust to occupying a special sleeping chamber, with constant temperature, freely available food and water, and lights that turned on and off on a regular schedule. Finally, rodents were manually injected with CBD at two different concentrations (10 micrograms/microliter and 20 micrograms/microliter), with some rodents receiving placebo to measure whether the injection itself had an impact on sleep. Afterwards, rodents were monitored for four hours each to measure the impact of each dose.
As shown in the graph below, researchers found no differences in sleep patterns from the empty injections (the control) compared to no injection (the sham), but found that both doses of CBD increased time awake (shown as W in graph A), and decreased both major periods of sleep (SWS and REM sleep).
In a previous study, the same group was less concerned with total sleep time and paid special attention to the effects of CBD during the “lights on” period of the chambers vs. the effects during the “lights off” period. In this study, they found that waking time increased during the lights on period without changing sleep time during the lights out period. This would indicate that the gain seen in the second study probably occurred with increased alertness during the lights on time. It may also indicate that the effect of CBD has to do with light stimulation, which is related to sleep and the rodents natural circadian rhythms or sleep cycles.
In one of the latest studies from 2011, the same team attempted to get to the bottom of the way that CBD would be producing these effects, speculating that CBD had some relationship to dopamine levels in the brain. To test this, the researchers used microdialysis to allow CBD to perfuse into the hypothalamus of rodents, as researchers currently believe this area of the brain modulates alertness. After investigating the brains of these rodents post-CBD administration, the researchers confirmed higher dopamine levels. In general, increased dopamine has been shown to lead to increased alertness, so this research seems to suggest that CBD sets off a chain reaction that increases dopamine in the hypothalamus, which then increases alertness. However, all papers in this series were careful to point out that these findings conflicted with that of other groups and would need verification.
Traditionally, dispensaries have recommended sativa strains for daytime medication and indica strains for nighttime medication (or, in the correct nomenclature established by Karl Hillig of Indiana University, indica/kafiristanica for daytime, what we traditionally refer to as ‘sativa’ and afghanica for nighttime, what we traditionally refer to as ‘indica’ )
Most sativa hybrids, such as Sour Diesel (in fact a kafiristanica), can be particularly energetic at the beginning, before giving way to the drowsiness that THC inevitably produces as it wears off (the old adage; what goes up, must come down). However, historically, indicas have contained higher CBD to THC ratios. If this is the case, and CBD increases wakefulness, then why are indicas more prone to yielding “couch lock” relaxation and sativas more prone to activity and excitation? It could be that the chemistry of the interaction between various cannabinoids is more complex than we believe it to be. It could also be that the wakefulness of CBD is outweighed by a lack of motor stimulation from lower levels of THC. In addition, other cannabinoids such as THCV (generally present in African sativas) will play a role in modulating the amount of sedation or energy that a particular genetic will impart. Wakefulness describes “alertness” but alertness is not exactly the same as “less drowsy” for reasons beyond the scope of this article. This is one area of the conversation about CBD that remains perplexing, and is one of the reasons readers need to trust their own experiences more than general findings. At this point in time, a sativa strain high in CBD seems like the best candidate for alert, daytime medicating. However, in the event that such a strain is unavailable, a sativa with moderate CBD will likely also be effective, since research seems to indicate that CBD effects are not fully dose-dependent.
Eric Murillo-Rodriguez, Diana Millan-Aldaco, Raphael Mechoulam, and Rene Drucker-Colin. (2008) “The Non-Psychoactive Cannabis Constituent Cannabidiol Is a Wake-Inducing Agent”. Behavioral Neuroscience (2008) 122:1378-1382.
Murillo-Rodriguez, E. Palomero-Rivero, M. Milan-Aldaco, D., et. al. “Effects on sleep and dopamine levels of microdialysis perfusion of cannabidiol into the lateral hypothalamus of rats.” Life Science (2011) 88: 504-511.
Murillo-Rodriguez, E. Palomero-Rivero, M. Milan-Aldaco, D., et. al. (2006) “Cannabidiol, a constituent of Cannabis sativa, modulates sleep in rats.” Federation of European Biochemical Societies Letters (2006) 580:4337-435.