Cannabis and sleep: so far the science is unclear

A national survey of more than 4,000 Canadians found 15.6% use cannabis specifically to help with sleep, and current clinical evidence on cannabis as a sleep treatment is mixed and limited.

Many Canadians use cannabis at bedtime with the explicit aim of improving sleep. A national survey of over 4,000 respondents found 15.6% of Canadian adults reported using cannabis specifically for sleep, slightly more than the 14.7% who reported using prescription sleep medications. Scientific evidence for cannabis as a sleep aid is inconsistent and remains limited. Researchers have proposed mechanisms such as increased adenosine signalling and interactions with the endocannabinoid system to explain possible sleep effects. Key findings: - A national survey reported 15.6% of Canadian adults use cannabis specifically to help with sleep. - That share slightly exceeded the 14.7% who reported using prescription sleep medications in the same survey. - Clinical studies show mixed results: some report subjective or objective improvements, while others show no benefit or varied effects on sleep stages. - Long-term effects are poorly understood and tolerance or withdrawal-related sleep disturbances have been reported after stopping use. - THC and CBD can have different and sometimes opposing effects, and the cannabis plant contains hundreds of compounds that may alter outcomes. - Emerging evidence suggests possible sleep benefits for conditions such as chronic pain, restless legs syndrome and PTSD, but findings are preliminary. Summary: Researchers say more robust, placebo-controlled clinical trials are needed to determine whether cannabis helps sleep, for whom, at what dose, in which formulations and for how long. Current findings are mixed and the long-term effects remain unclear. Undetermined at this time.