According to a new study published this week, a single dose of a joint could produce psychiatric symptoms associated with schizophrenia.
The study, which was published in the journal Lancet Psychiatry, has found that daily or high-potency cannabis increases risk of psychotic disorder.
“The first takeaway is that for people in general there is a risk, even if you are healthy and taking a single dose, a one-off, you could have these symptoms,” said Oliver Howes, a senior author on the study and molecular psychiatry professor at King’s College London’s Institute of Psychiatry, Psychology & Neuroscience.
The symptoms “are distressing and could affect your thinking. It’s not just something that’s going to affect people with a history of mental health problems,” he said.
Howes also added that having symptoms didn’t cause them to have a psychiatric illness.
“They are distressing and could affect your thinking. You might not behave in a safe or rational way. It’s not just something that’s going to affect people with a history of mental health problems,” he added, noting that having symptoms didn’t cause them to have a psychiatric illness.
The analysis found no evidence that cannabidiol (CBD), a non-psychoactive compound in weed that’s used in some medicinal cannabis and other products, does induce psychiatric symptoms. Howe said this was “reassuring” but noted that the available evidence was fairly limited.
“As the THC-to-CBD ratio of street cannabis continues to increase, it is important to clarify whether these compounds can cause psychotic symptoms,” he said.
“There are also some people who become withdrawn and lose motivation. And whilst those are less dramatic, they could affect ability to work or drive a car. When you take a one-off dose, they [the effects] are temporary and last a few hours, but if you take it regularly, it could be an enduring consequence.”