Monday, May 12, 2008

Cannabis a dangerous illicit drug

This most recent report by the British Advisory Council on the Misuse of Drugs provides a careful evaluation of cannabis. It recommends retaining the classification of cannabis as a Class C drug (along with valium, GHB and steroids) rather than upgrading it into Class B of more dangerous drugs such as amphetamines and barbiturates. Nevertheless it does describe cannabis use as a significant public health issue. With a few exceptions the report’s views coincide with my views on cannabis.

As a Class C drug a maximum prison sentence of 2 years is set for use while supply carries a maximum penalty of 14 years.

In Britain as in Australia cannabis use has decreased markedly (20-25%) over the past 5 years in all age groups.

Cannabis damages lungs but by less than cigarette smoking because less is smoked. Severe lung damage has been reported in heavy young users and there is the potential longer-term risk of lung cancer.

Cannabis damages the reproductive system in both males and females and causes low birth weights among pregnant women.

Cannabis can cause short-term psychotic effects - usually short-lived and responding to tranquilisers. A Danish study suggests half of those who contract a cannabis-induced psychosis experience repeat symptoms over 3 years although this may be due to continued cannabis use.
The incidence of cannabis psychoses has not been increasing.

Cannabis is the most common illicit drug found in the body fluids of those suffering motor vehicle injuries.

Dependence on cannabis is ‘unquestionably, a real phenomenon’. Significant numbers of young (under 18) and older cannabis users are dependent on cannabis.

Cannabis worsens the symptoms of schizophrenia and dealing with cannabis use (including dependence) is a major element of the treatment of many young males with this disorder.
The Council concluded that the evidence supports a causal link between use of cannabis in adolescence and the subsequent development of schizophrenia (page 18, para 8.10). Heavy users of cannabis have a 2-fold increase in the incidence of schizophrenia (page 19 para 8.10.1).

The Council was unclear whether cannabis use supported the ‘Gateway theory’ – that it led to use of more dangerous Class A drugs.

Cannabis impairs performance of tasks requiring sustained attention.

In preferred forms of cannabis (‘Sinsemilla’) THC concentration has doubled over the period 1995-2007.

The Council favours campaigns to drastically reduce cannabis use particularly among young people.


perry said...

I'd believe you Harry, if I hadn't been smoking the evil weed ( and only the evil weed ) for more that three decades. I'm still trying to find a downside.

Anonymous said...


you go on and on about this, but what you should be giving is basically a minima over the long-term for usage based on the cost of usage vs. the cost of everything else, which you never give. That's the real argument.

As should be obvious, going to jail is bad for people and expensive, and spending money on policing is an opportunity cost which might be better spent on public health campaigns -- especially given that it appears trying to push up the cost and restricting supply more is almost impossible in places like Australia (especially given the decriminilization in some states).

Personally, my feeling is you'd be better off worrying about ecstasy, which is on the increase, already used by 3% of the population, and does do long term damage. Apart from the damage we know about, we also don't know whether the even longer term consequences are even worse (e.g., earlier onset and higher probability of dementia etc.).

On this note, there's essentially no literature out there which shows cannabis has a long term effect on people's cognitive performance -- I see no point in pointing to short term costs (except motor vehicle accidents -- but we can and should be testing for that anyway). Most of this just relates to single psychotic episodes, which people recover from in any case and are basically used as scare stories in any case given their null-to-low probability -- especially given things like having strokes (not sexy to report at all) are worse for you. These might be avoided if there was a cultural change to eating pot or using vaporization of pure THC, but we won't see either of these unless we see legalization occur (I've never seen pure THC, but then, I'm not exactly looking for it).

hc said...

Conrad, I think the emphasis in the post on 'high usage' suggests the Council believe thast low usage is better than high usage - the latter particularly dangerous in youth.

If 3 years is 'long-term' then the Council believes there is long-term damage. The 'dependency' issue - which is strikingly real - is a long-term cost.

I agree that eating is probably safer than smoking. my ptreference is to take a walk outside and smell the flowers, fly a kite, listen to a Mozart piano concerto... If you want to be more exotic try meditation.

In short there are plenty of natural highs that are entirely non-injurious.

Anonymous said...

Just wondering Harry. Did you ever take a taken toke, even if only once, in your youth?

Anonymous said...


my preferance is the same as yours in this latter respect.

hc said...

Spiros, I am tempted to give you a 'yes, but I didn't inhale story' but I would not want to be seen asa a Clinton copycat.

Of course my history is irrelevant to the damages now understood to be associated with cannabis smoking.

Anonymous said...

Of course your personal history is irrelevant.

I'd think the lesser of you if, given your apparent age, the time you were an undergraduate etc, you didn't partake a bit. In those days, smoking dope was as commonplace and as ordinary as taking a crap.

Anonymous said...

Harry, I am an adult who uses cannabis in small doses as responsibly as I can. I don't smoke the drug or drive under the influence. I use it in the privacy of my own home. I too enjoy natural highs but I wouldn't swap the enjoyment, peace, insight and pain relief (major disc problems) I get from pot. I don't believe teenagers should use the drug or drink for that matter because teenagers cannot seem to consume anything sensibly. I have followed cannabis debates closely and have read a lot of research. It seems to me that much of the literature is contradictory. You can find whatever you want to prove whatever point you are trying to make. I can find info that says cannabis causes cancer; that it doesn't; that it may cure cancer; that it may cure depression in small doses; that it may cause depression in high doses e.t.c. The lists are endless. I would suggest it takes years to get to the bottom of this highly politicised issue. I just want to be left alone to make an adult decision about what I chose to do that does not harm anyone else. It appears that is too much to hope for in the current hysterical nanny stat we live in.

Anonymous said...
This comment has been removed by a blog administrator.