Smoking super-strength cannabis or spice may trigger life-threatening seizures, researchers have warned.
Trials on mice showed seizures can be induced by both THC – which causes the ‘high’ in marijuana, and JWH-018 – the main component of spice.
The rodents also suffered from a shortness of breath and impaired walking after being given both compounds, the scientists discovered.
Japanese researchers warned the results should act as a wake-up call, given how widely high-potency and synthetic weed is used.
The findings contradicts pro-cannabis campaigners who have long argued that cannabis can help to tackle seizures and highlighted research which shows weed can prevent and control seizures in epileptic patients.
However, lead researcher Dr Olga Malyshevskaya, based at the University of Tsukuba, said the latest findings show cannabis is not a soft drug and warned of its dangers.
Trials on mice showed seizures can be induced by both THC – which causes the ‘high’ in marijuana, and JWH-018 – the main component of spice
She said: ‘Our study is quite important. Unaware of the particularly severe effect by those cannabinoids, people see marijuana as a soft drug, without dangerous health effects.’
She added: ‘It is critically important for health-care professionals and policy makers to be aware of the serious adverse effects, as shown in this report.
‘Clinicians in the emergency departments should always suspect seizure activity in patients who have a history of cannabinoid intoxication.
‘The number of clinical cases involving marijuana intoxication has been steadily increasing due to increase in cannabis potency over the last two decades.’
What do other experts think?
Ian Hamilton, a cannabis researcher at York University, cautioned the results, which are published in Scientific Reports.
He told MailOnline: ‘We don’t know if people who use cannabis are using something as potent as this.’
For the study, researchers measured the brain activity of the mice after giving them both compounds and recorded them.
Research that claims to show cannabis can control seizures
The findings contradict a body of research which shows weed can prevent and control seizures in epileptic patients.
Campaigners have long argued that cannabis has the opposite effect to the new findings and can help to tackle seizures.
Researchers have previously suggested that CBD – the other compound in cannabis which produces no ‘high’, binds to a receptor in the brain that calms down the electrical activity in the brain which causes a seizure.
First Briton to be prescribed liquid cannabis oil on the NHS
Their case was strengthened when an 11-year-old on the brink of death from a severe form of epilepsy made an ‘incredible’ recovery from taking marijuana.
Billy Caldwell, from Castlederg, Northern Ireland, made headlines in April when he became the first Briton to be prescribed such a drug on the NHS.
And 10 months since he was first given the liquid cannabis oil, he hasn’t had any seizures. He used to suffer up to 100 a day.