I live in Vancouver, where smoking a joint is part of everyday life for almost everybody who owns a mountain bike and an iPod. So my recent posts about the dangers of marijuana are not likely to go down well with my demographic. But I persevere:

Today’s Guardian has yet another piece about the growing evidence for addiction with the use of marijuana:

(Quoting Michael Rowlands) “There’s a strong desire to use, which overrides other activities, so friends and hobbies and work are neglected. There’s difficulty in controlling the amounts you use. There’s a degree of tolerance developed so you need higher doses to have the same effect. And then you persist in using despite the fact it’s causing you ill health or debt.”

The main thing that separates cannabis from heroin or nicotine is that the physical withdrawal state is not normally as severe.

Almost all addictive drugs stimulate a part of the brain — called the mesolymbic dopamine system — that acts as a reward pathway in the central nervous system. Receptors for the active ingredients in cannabis have been found in this system. Once stimulated, these receptors begin a cycle of reward that can lead people to use more of the drug.

There’s also a snippet about the risks for psychosis:

More concerning than any apparent rise in addiction is the potential to cause psychoses in heavy users.

Robin Murray, a psychiatrist at King’s College London, is one of Britain’s leading researchers in this area and his results are worrying. “The conclusion was that, if you took cannabis at age 18, you were about 60% more likely to go psychotic. But if you started by the time you were 15, then the risk was much greater, around 450%,” he says.

I have to say that I enjoy this new research; the fact that it’s coming out, if not the results. It gives those of us in the substance abuse counselling field a means of confirming what we’ve been saying to clients for a long while.