People who used cannabis in their early teens are twice as likely to have severe sleeping problems in later life, according to a new study.
While the results suggested that marijuana use can negatively effect sleep quality in any user, it was most frequent in people who had used the drug since they were 15-years-old or younger.
The findings are likely to be most concerning for people who use marijuana to relax or as a sleeping aid, said lead author Jilesh Chheda, research assistant of the Division of Mood and Anxiety Disorders, Department of Psychiatry, at the University of Pennsylvania.
“This latest study found that current and past marijuana users are more likely to experience sleep problems,” he said.
“The most surprising finding was that there was a strong relationship with age of first use, no matter how often people were currently using marijuana.
“People who started using early were more likely to have sleep problems as an adult,” he added.
Cannabis around the world
Cannabis around the world
Farmers destroy cannabis plantations under Moroccan police supervision in the northern Moroccan Larache region, pictured here in 2006
Growing business: Cannabis on sale at River Rock Wellness
Oaksterdam in Oakland, California, is the world's only university dedicated to the study and cultivation of cannabis
Alain Jocard/AFP/Getty Images
A cannabis smoker marks the start of the new law by the Space Needle in Seattle
Cannabis growing wild in China, where it has been used to treat conditions such as gout and malaria
Uruguay has voted to make the country the first to legalize marijuana
A groundswell of support from the public led to full legalisation in Colorado
A man smokes licenced medicinal marijuana prior to participating in the annual Hemp Parade, or 'Hanfparade', in support of the legalization of marijuana in Germany on August 7, 2010 in Berlin, Germany. The consumption of cannabis in Germany is legal, though all other aspects, including growing, importing or selling it, are not. However, since the introduction of a new law in 2009, the sale and possession of marijuana for licenced medicinal use is legal.
Sean Gallup/Getty Images
The UK latest figures show 2.3 million people used cannabis in the last year
Tourists visiting Amsterdam will not be banned from using the city’s famous cannabis cafes
These 25 cannabis plants, seized in Merseyside police, could have generated a turnover of £40,000 a year
12/13 San Francisco
April 20, 2012: People smoke marijuana joints at 4:20 p.m. as thousands of marijuana advocates gathered at Golden Gate Park in San Francisco, California. The event was held on April 20, a date corresponding with a numerical 4/20 code widely known within the cannabis subculture as a symbol for all things marijuana.
A cannabis users' association will pay the town of Rasquera more than €600,000 a year for the lease of the land
The study involved adults aged between 20 and 59-years-old, who responded to the National Health and Nutrition Examination Survey – a series of studies designed to assess the health and nutritional status of adults and children in the US.
1,811 of those participants reported that they had used any drugs. To assess the results, scientists defined a ‘cannabis user’ as a person with any history of using the drug, and sleep-related problems were considered severe if they occurred at least 15 days per month. When a person first used the drug, and the number of times they had used it in the past month were also analysed.
The team found that marijuana users were more likely to have difficulty sleeping, maintaining sleep, experiencing non-restorative sleep, and feeling sleepy in the daytime. People who had taken the drug before they were 15 were twice as likely to suffer these complications.
The study published in the journal ‘Sleep’ and presented at SLEEP 2014, comes after Uruguay and the US states of Washington and Colorado legalised recreational marijuana use, with the first shops opening in the latter earlier this year.
“As more people have access, it will be important to understand the implications of marijuana use on public health, as its impact on sleep in the ‘real world’ is not well known,” said senior study author, Michael Grandner, PhD, instructor in Psychiatry and member of the Center for Sleep and Circadian Neurobiology.