Medical cannabis in treating patients with sleep disorders
Dove Press, Kathleen J Maddison, Christopher Kosky, Jennifer H Walsh, Author Guidelines
In 2022, “insomnia” and “sleep disorders” were the third and fourth most common reasons for prescription.8 Despite this increasing use of cannabis products for the treatment of sleep disorders, evidence for its benefit has been limited. Many studies specifically recruited participants with a history of chronic or heavy recreational cannabis use,9–14 who appear to have poorer sleep compared to non-users.15,16 Therefore, baseline or placebo data in these participants may be a reflection of sleep architecture associated with withdrawal, which can be significant.17–19 Also challenging for isolating effects of specific cannabinoids is that a number of studies have examined the effects of smoking or consuming whole cannabis/flower with unknown cannabinoid concentrations.17,19–21 Another issue is that many studies have investigated the effects of cannabinoids on sleep in populations with health ailments12,22–24 or sleep disorders,25,26 which are likely to confound effects on sleep outcomes. Therefore, this section of the review focuses on controlled, cross-over design studies that have included predominantly non-experienced cannabis users and objective measures of sleep quality and architecture (Table 1).19,30–33 The majority of studies have focused on the effects of a THC dominant cannabinoid formulation,19,30–32 although one study investigated the effects of THC alone as well as two doses of a balanced THC:CBD formulation.31 Another study investigated the effects of CBD alone.33 Table 1 Trials Evaluating the Effect of Cannabinoids on Sleep Architecture The largest and most recent study on effects of cannabinoids on sleep, by Linares et al, identified no change in any measure of sleep quantity or architecture when 27 healthy young volunteers took a single 300mg dose of CBD compared to placebo.33 Of studies which included THC, in regard to the putative sedating properties of cannabinoids, none identified an improvement in the time taken to fall asleep (sleep onset latency; SOL) although one study19 (n = 6) reported a reduction in wake time after sleep onset (WASO) and another (n = 8) reported a slight decrease in WASO when a 5mg balanced THC:CBD formation was taken, and an increase in WASO when a 15mg balanced THC:CBD formation was taken, resulting in a significant difference between doses.31 Only one study reported an increase in total sleep time (TST).19 Two studies reported a reduction in Stage 3 and/or Stage 4 sleep31,32 while another reported an increase.19 Perhaps more consistent is the data indicating that rapid eye movement (REM) sleep is reduced when taking THC; two studies identified a reduction19 or near complete suppression,32 albeit at a very high dose of 0.7–1.0mg/kg in the case of REM suppression. Although the effects of nabilone on these objective measures of sleep were mixed, pain was significantly improved while taking nabilone compared to placebo. Further supporting a potential role for cannabinoids in the treatment of narcolepsy is the existing clinical evidence suggesting that the acute use of THC may increase the proportion of slow wave sleep and promote REM suppression (see - Effect of cannabinoids on sleep and sleep architecture), which is similar to the effect of sodium oxybate, an effective treatment for type 1 (hypocretin deficient) narcolepsy.