Cannabis use doubles risk of psychosis for teenagers | Mail Online
Wednesday March 2, 2011 3:46 am Leave a comment
This might be about right, even though it’s in the Daily Mail. Now consider context. What is the lifetime risk of psychosis in the population generally? Answer; at most 1-2%. So doubling the risk means moving, at most, to 2-4%. Meaning, at most, 1 in 25 teenagers who become regular cannabis consumers will develop psychotic symptoms. Mostly treatable, but nevertheless, this is serious enough to warn under 25s to treat it cautiously. Ideally, we will be able – eventually – to undergo a quick genetic test which identifies those most at risk – who should probably avoid it altogether, at least until their brains have stopped growing at about the age of 25.
In contrast, consider Breast Cancer, with a background lifetime risk of 1 in 8 (12.5%). The same newspaper helpfully tells us the same day that smoking (tobacco) increases the risk of that disease by 16% – taking overall lifetime risk to 14%.
So, in short, take a million teenagers and allow them to smoke cannabis. Instead of the 20,000 psychotics we might get without cannabis, we’ll see about 40,000.
Take a million women and allow them to smoke (tobacco) and instead of the 125,000 breast cancers we’d otherwise get, we’ll see about 140,000.
The net effect on society is approximately equal (slightly more increase in psychosis than breast cancers, but many more deaths from the cancers). Now contrast the way we treat smoking women (advise, warn, treat) with the way we treat cannabis use (ban, imprison, punish)
This is the REAL “Cannabis Psychosis” and it’s much more prevalent and dangerous than the one induced by the drug…