The risk of experiencing cannabis-induced psychosis is small compared to the number of total users, according to a new study by researchers at the University of York in England. In fact, previous research has shown that in order to prevent just one case of psychosis, more than 20,000 people would have to stop using cannabis.
However, there is sufficient evidence to conclude that cannabis use makes symptoms worse in people who already have schizophrenia. Furthermore, the researchers say that more studies are needed on the impact of high-potency cannabis to make a full assessment of the risks.
“The link between cannabis and psychosis has been an ongoing research topic since the drug became popular in the 1960s,” said Ian Hamilton, lecturer on mental health at the University of York. “Most of the high profile studies that we have access to, however, are from a time when low potency cannabis was the norm, but today high potency is more common.
“High potency cannabis contains less of a chemical that is believed to protect against negative side-effects, such as psychosis, and a higher level of a chemical that can trigger psychosis. In this new study, we looked at both low and high potency, but it is clear that we need more evidence from high potency-related health cases to further investigate this link in modern-day users.”
However, despite the relatively low risks, the research was clear that the more high potency cannabis used, the higher the risk of developing mental health problems. For those who already had schizophrenia, cannabis exacerbated the symptoms.
The findings show that the greatest risk to health comes from cannabis users who combine the drug with tobacco. This exposes young people in particular to tobacco dependency at an early age, increasing the chances of cancers, infections, and other health-related issues.
Prior research at York showed that regulating cannabis use could result in more effective strategies aimed at helping drug users to access the right support and guidance. The report showed, however, that there is too much uncertainty around treatment regimes in an unregulated market to target the appropriate level of care.
“Regulation could help reduce the risks to health that cannabis use poses, as a regulated cannabis market would introduce some quality control,” said Hamilton. “This would provide users with information about the strength of cannabis on offer, something they usually only discover after exposure in the current unregulated market.”
“The public health message about the link between cannabis and psychosis has been a difficult one to communicate, but the evidence still points to the benefits of regulations that seek to advise on the greatest potential health risks, which currently arise due to tobacco use.”
The findings are published in the journal Addiction.
Source: University of York