The Government has made the right decision to reclassify cannabis to a class B substance.

This is to alert and educate the public rather than criminalise users.

It is a fact that we now live in a brave new age of biotechnology.

Horticulturists have genetically engineered seeds to contain up to 20 times more of the drug's psychoactive ingredient THC (tetra hydro cannabinol).

In years gone by, smoking a spliff of grass was probably a fairly harmless experience.

However, today, a whole new ball park has opened up because of genetically-engineered, super-strength skunk.

It is like the difference between knocking back a shandy or a bottle of absinthe.

THC has many effects on the mind and body. In small doses, it increases levels of dopamine, a feel-good neuro-transmitter found in the brain. Too much dopamine, however, leads to extreme paranoia and aggression.

Someone in the grip of a paranoid psychosis may feel that people are out to get them and so launch a pre-emptive strike.

So smoking skunk can lead to violent behaviour rather than a mellow mood.

Many senseless acts of violence have been committed due to this side-effect.

Abigail Witchell was stabbed in the neck, while pregnant, by a chef high on the drug.

Etymologists speculate that the word assassin originates from the term "hashishin".

The Hashishin was a 14th century moorish sect that smoked hashish before embarking on political killing sprees.

SUSAN THOMAS Magdalen Road Oxford