Literature review of cannabis and sleep

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Tags:
Date Commenced:
12/12
Project Supporters:

Australian Government Department of Health

Drug Type:
Project Members: 
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Dr Peter Gates
Research Officer
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Ms Lucy Albertella
Research Assistant
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Professor Jan Copeland
Honorary Visiting Professor
Project Main Description: 

Individuals often report using cannabis to sleep, experiencing sleep problems as a symptom of withdrawal, and relapsing due to sleep problems. This project endeavoured to integrate research on cannabis and sleep so that gaps in the literature can be identified and improvements in cannabis use interventions can be achieved. 

Rationale: 

Research to develop a better understanding of how cannabis use impacts on sleep and the extent to which cannabis use is associated with changes to sleep architecture is rarely conducted. Recognising the proportion of cannabis users who have sleeping problems or who use cannabis to assist their sleep may be clinically helpful when assisting individuals interested in abstaining from cannabis use. 

Aims: 
This study addressed the research gap on cannabis and sleep by identifying:
  1. How many people report sleep disturbances before, during and after cannabis use
  2. The nature, severity and impact of these sleep disturbances
  3. The characteristics of people who report sleep disturbances before, during and after cannabis use.
 
Design and Method: 

All English language studies on human participants that include specific measure of cannabis and sleep were located and reviewed. In addition, each study was assigned a quality rating. The project aimed to produce a systematic review. 

Findings: 
After removing duplications and applying exclusion criteria, 127 relevant articles remained. These articles fell into six different categories: 15 papers on the effects on sleep of administering cannabis; 27 papers on the effects on sleep of removing access to cannabis (forced withdrawal); 29 papers on associations between cannabis use and sleeping difficulty; 3 papers on the effects on infant sleep by smoking during pregnancy; 11 papers on the prevalence of medicinal cannabis use for sleep; 28 papers on the effects of medicinal cannabis on sleep; and 17 papers on the prevalence of sleep problems as part of cannabis withdrawal. 
 
The acute effects of cannabis use on sleep appear to be a disruption to the sleep cycle reflecting a reduction in time spent in slow wave sleep and an increase in time spent in random eye movement sleep. Withdrawal from cannabis shows an opposite trend. A secondary impact on sleep latency may be present where both use and withdrawal appear to increase the time taken to fall asleep. Other measures such as sleep time, body movements, night time awakenings and sleep quality were not consistently influenced. Sleep problems during cannabis withdrawal were reported by approximately half of the samples reviewed and did not appear to be a consistent cause for relapse. Paradoxically cannabis use tended to improve sleep among populations using cannabis medicinally although this may reflect an improvement in condition related symptoms which reduce sleep.
 
Several limitations to the research prevent any informative conclusions regarding the influence of cannabis on sleep to be made. First, the included articles were typically of low quality (overall average was 49.5%), meaning that risk of bias was high. Second, over half of the studies were conducted in the US and Canada. As such, the findings presented may not be representative of the Australian population or other countries with a more restrictive political climate around cannabis use. Third, the majority of studies were short-term, looking at the influence of cannabis use on sleep over a period of weeks. As such, the longer term impact of cannabis use is not as well understood. Notably, those studies describing sleep problems among long term users showed mixed results. 
 
Output: 
Publictions:
NCPIC Bulletin 17.
Two further systematic review articles for publication in Sleep Medicine Reviews will be submitted in 2013 and early 2014.
 
Posters:
Gates, P and Albertella, A.  (2013) Cannabis and sleep. Poster presented at the NDARC Annual Symposium, Sydney, 4 September. (See 'Resources' below).
 
Presentations:
Gates, P. (2013) Cannabis and sleep: A review. Presentation to NDARC staff seminar, Sydney, 20 June.
 
Benefits: 

Recognising the effects of cannabis use on sleep is important for both the cannabis user and for health providers tasked with assisting behavioural change. That is, this knowledge may act as a motivational tool for those deciding whether or not to use cannabis. In addition, this knowledge may assist clinicians to reduce the risk of relapse to cannabis use among their clients by assessing and addressing sleep problems as necessary.

Project Research Area: 
Drug Type: 
Project Status: 
Completed
Year Completed: 
2014