Experts warn cannabis users can become schizophrenic

Cannabis can have a range of negative effects on users’ health, experts warn.

It can make them feel confused, anxious and paranoid or experience panic attacks and hallucinations. In some cases, they can develop schizophrenia.

These psychotic effects are more common among those taking the strongest forms of cannabis, such as skunk or sinsemilla.

The key compound that causes psychosis is tetra-hydrocannabinol, or THC, which is also the chemical that produces the ‘high’ users get from the drug. King’s College London researchers have published a study in the journal Lancet Psychiatry describing how people who use skunk have a much greater risk of developing psychotic mental illnesses such as schizophrenia.

Compared to those who never had cannabis, skunk users were twice as likely to be diagnosed with psychosis if they used it once a week and three times as likely if they used it at weekends. The risk rises to five times if they were daily users. As well as triggering mental illness, the drug has a host of other negative effects, the NHS advises.

It can interfere with the ability to drive safely, which is why driving under the influence of cannabis is an offence.

Heavy cannabis users can become demotivated and uninterested in other areas of their life, such as education or work.

Cannabis smokers are more likely to suffer from conditions such as bronchitis. It also harms sperm production in men, and interferes with ovulation in women.