Cannabis-like drug causes severe psychosis in young men, warns College of Psychiatrists – The Irish Times

A new cannabis substitute is causing severe psychosis in young men, requiring months of intensive inpatient treatment, the College of Psychiatrists has warned.

Hexahydrocannabinol (HHC), which first appeared in 2022, is chemically similar to tetrahydrocannabinol (THC), the active ingredient in cannabis, and produces comparable physiological effects.

HHC is commonly available in vaporizer form or as an additive to jelly or chocolate. It is legal in Ireland and has gained popularity here in the last year. It is sold in many shops and is often marketed as a safer or less potent alternative to cannabis.

According to the College of Psychiatrists, HHC is a factor in about 20 percent of youth admissions to addiction services. It called on the government to ban HHC under a law introduced in 2010 to stem the rise in the sale of dangerous but legal substances in so-called head shops across the country.

Prof Bobby Smyth, a specialist psychiatrist specialising in child and adolescent addiction, said these head shops were causing enormous harm to young people and “we are now seeing a similar trend in HHC”.

Prof Colin O'Gara, a consultant addiction psychiatrist, said HHC was initially seen as a harmless drug but can have devastating effects on young people's mental health. “We have treated young men who suffered severe psychosis as a result of vaping HHC. These individuals may require months of intensive treatment in an inpatient setting with medication to recover from the psychosis.”

The College of Psychiatrists released a guide on Monday outlining the effects and risks of HHC.

Prof Smyth, chair of the college's Department of Child and Adolescent Psychiatry, said there had been an “extraordinary” increase in HHC-related addictions among young people within a “short period of time”.

“HHC was first identified in Europe only two years ago. Today we estimate that HHC plays a role in around 20 per cent of all cases in youth addiction services in Ireland, very often in combination with cannabis itself,” he said.

One of the worrying aspects of using HHC is that no one knows the long-term consequences, Prof Smyth added.

“The public needs to know that just because a substance is sold in a store in fancy packaging for human consumption does not necessarily mean it is safe or has been tested in any meaningful way. Until proven otherwise, we should assume that HHC products will cause the same mix of problems we see with cannabis,” he said.

The college called on the government to add HHC to the list of banned substances, prosecute companies and retailers that distribute or sell the drug in any form, and raise awareness of the potential dangers and harms of HHC, particularly among young adults and in schools.