Dagga is not a gateway drug
The prohibition on dagga is the "gateway to harder drug use‚ not the use of cannabis itself"‚ Imperial College Professor David Nutt told the Pretoria High Court.
Nutt‚ a psychiatrist and neuropharmacologist is testifying in the trial to have the current ban on dagga use ruled unconstitutional.
Johannesburg residents Jules Stobbs and Myrtle Clarke are asking the Pretoria High Court to deem the laws banning the adult use and sale of dagga unconstitutional and thus instruct parliament to make new laws.
One of the biggest reasons that governments and drug-affected communities oppose the legalisation of dagga is that it is seen as the gateway to using more dangerous drugs.
"The gateway theory is a theory that has very‚ very little in the way of empirical evidence‚" Nutt said.
"Most people who use cannabis do not go onto harder drugs. Most people who use harder drugs [first] use things other than [in addition to] cannabis."
He said the Dutch decision to make cannabis [dagga] legally available to use in coffee shops is a "remarkable social experiment" that proves it is not the gateway to harder drugs.
Legal cannabis did not lead to an increase in Dutch users of heroin and other drugs‚ but actually reduced the number of people switching to harder drugs.
"The Dutch managed to stop wide-scale heroin use in its tracks‚" he said.
Nutt says making cannabis illegal is what can influence people to move onto to harder drugs because people come into contact with the black market and drug dealers.
Users have to break the law to buy dagga and breaking the law "subsequently becomes easier". It is then easier to buy other illicit drugs.
He also said introducing people to drug dealers is what led to harder drug use.
It is estimated 9% of dagga users will become addicted to it‚ but 30% of crack cocaine users and 30% of heroin users will get addicted.
Dealers want dagga users to switch to more addictive drugs and they even mix them into dagga to give buyers a taste of them‚ he said.
Nutt said the Dutch realised they didn’t want teens buying cannabis to be introduced to drug dealers. "They wanted to split the market from cannabis sellers and sellers of heroin or crystal methamphetamine."
So they provided cannabis legally in coffee shops.
He said a scientific panel looking at the dagga laws in UK around dagga concluded: "If the gateway theory exists it is tiny and less than that associated with alcohol and tobacco."
This means alcohol and smoking are more likely to help a person switch to harder drugs that dagga but all have a negligible effect.
Nutt does not say dagga is harmless
"All drugs cause harm…. It is not harmless."
The legal case brought by Stobbs and Clarke is merely asking whether the harmful effects are so severe the drug needs to be criminalised.
Nutt also told the court that dagga use does not cause schizophrenia but it can bring its onset earlier. The belief that dagga use is associated with schizophrenia is another reason governments want dagga kept illegal.
As dagga use has risen substantially in 20 years in UK‚ schizophrenia rates have remained stable‚ he said.
This means it doesn’t cause schizophrenia‚ a long held belief‚ but he said it can accelerate onset. He said the relationship between schizophrenia and cannabis was "complicated".
He said schizophrenics often use dagga and this can enhance their psychosis such as making voices in their head louder. This led to many doctors falsely believing it caused schizophrenia.
"Many people who have mental illness use cannabis. This can make some of the symptoms worse [ but] they are using it because they get something from it. The medical profession focuses on the bad affects they get and not the reasons they use it. They are self-medicating.
"The latest data on people with schizophrenia who use cannabis show they do better than those who don’t. It could be because it helps them think more clearly."
The data produced by UK scientists showed that if they stopped 5‚000 men smoking dagga‚ they could stop one case of schizophrenia and if 7‚000 women were prevented from smoking dagga it would also prevent a single case.
"A rational health policy would not be… justified for such a tiny gain in outcome."