For the first time, a new study has shown how smoking skunk, the highly potent form of cannabis increases the likelihood of developing a psychotic illness seven times, in comparison to those who smoke the traditional strength drug.

Scientists from the Institute of Psychiatry at King’s College London made the discovery while studying admissions to hospital for psychotic illnesses like schizophrenia, paranoia and serious depression, which makes the results particularly worrying, as 80% of the street market in cannabis in the United Kingdom is accounted for by skunk.

‘Our study is the first to demonstrate that the risk of psychosis is much greater among people who are frequent cannabis users, especially among those using skunk, rather than occasional users of traditional hash,’ said study lead Dr Marta Di Forti.

He believes it is vital to educate the public about the risks of heavy use of high potency cannabis, with skunk displacing traditional cannabis preparations in many countries, and its availability on the UK street market steadily increasing over the past six years.

It is believed that at some point in their lives, 1% of UK’s population suffer from a psychotic illness, such as, hallucinations, paranoia and schizophrenia.

Previous studies have also established a direct link between cannabis and psychosis and it is generally thought using it on a regular basis doubles one’s chances of developing mental health problems, especially amongst teenage cannabis users, who are particularly susceptible, showing a greater likelihood of developing paranoid personalities, hallucinations and even schizophrenia later in life.

While, family history plays a significant role in developing a mental illness, cannabis which has THC – or Delta-9-tetrahydrocannabinol, as an active ingredient is believed to act as a trigger for the latent disease and is blamed for the effect.

The work has been published in British Journal of Psychiatry.