An interesting study this week from the American Journal of Epidemiology entitled “Early Cannabis Use and Estimated Risk of Later Onset of Depression Spells: Epidemiologic Evidence From the Population-based World Health Organization World Mental Health Survey Initiative” – you can read the paper on the Medscape website (you need to create an account- click here – but it’s free). After registering you can find the paper by putting “Early Cannabis Use and Estimated Risk” into their search box.
Before we go any further let’s restate a simple precautionary principle which really applies to all drugs, not just cannabis, which is children and young teenagers really shouldn’t be using them. The reason for this is simple and obvious; young brains are still developing and drugs tinker about with the workings of the brain.
So really to look for some kind of negative impact on young drug users – especially heavy young users – is a bit like fishing in a bucket, they’re looking for something they expect to find. So it’s perhaps something of a surprise that their conclusion is:
The association between early-onset cannabis use and later risk of a depression spell was studied … The overall association was modest … , was statistically robust in 5 countries, and showed no sex difference. The association did not change appreciably with statistical adjustment for mental health problems, except for childhood conduct problems, which reduced the association to nonsignificance.
Not quite the result which might have been expected from a bucket fishing expedition, although the last bit is more interesting than it sounds at first.
One limitation of the study was:
This study did not allow differentiation of levels of cannabis use; this issue deserves consideration in future research.
Which is a somewhat odd thing not to have looked at in all honesty.
The study used data collected by the World Health Organisation which surveyed subjects from 17 countries, so the claim that the overall association was “statistically robust in 5 countries” needs to balanced by the statement that it was not statistically robust in 12 countries.
The paper begins by stating that several studies have shown a link between early onset cannabis use whilst other haven’t. The aim of the study then was to look at the data collected around the world by the WHO to test the hypothesis that there is, indeed, a causal link between early onset cannabis use and depression later in life.
Here, with community samples from diverse countries, we estimated whether cannabis onset by the middle of adolescence (before age 17 years) is followed by greater risk of first onset of a depression spell, with due attention to sex and age variations.
Now, there are some important observations to be made at this point:
We used a local area matching approach to constrain the effects of geographic variation in enforcement of cannabis laws, local jurisdictional variation in subnational law, and other socially shared local area variations that might confound cannabis-depression estimates and which also account for potential geographic variation in odds of exposure to cannabis use.
Of course as an illegal activity cannabis use is more likely to be linked with overall risky activities and young people are unlikely to be using cannabis with any guidance from more experienced adults, they are more likely to associate with other deviant sub-cultures and be alienated from mainstream society; all this is one of the main arguments against prohibition. The study also seems to be based on the assumption that strong law enforcement will have a simple impact on the rates of use and the consequences of that use, but read on.
It’s worth mentioning as a criticism that the study clearly avoided any consideration of the possibility that different strains of cannabis might have different impacts on adolescent development. Cannabis is not a simple drug in the sense that its composition varies greatly between strains and under the rule of prohibition there has been a claimed move away from high CBD strains in some areas which might have an impact on mental health.
Furthermore, we considered an array of possibly confounding mental health problems, including childhood conduct problems. Childhood conduct problems and early rule violations have been described to precede early peer rejection, affiliation with drug-using peers, early-onset cannabis use, and subsequent low self-esteem and mood disturbances and thus are important confounding variables.
There is something rather worrying about the way this is written, the implication being that youthful rebellion and non-conformity is somehow a form of mental illness. As it reads it seems to justify the authoritarian mind-set that young kids who push against authorities laws are destined to be social outcasts and that this is a natural thing, not something created by the social constraints imposed on these young people.
The study drew on data collected by the WHO between 2001 and 2006 in the Americas (Colombia, Mexico, the United States), Europe (Belgium, France, Germany, Italy, the Netherlands, Spain, Ukraine), the Middle East and Africa (Israel, Lebanon, Nigeria, South Africa), Asia (Japan and 2 separate surveys carried out in Beijing and Shanghai, China), and Oceania (New Zealand) and involved 85,088 respondents, so it was a big survey.
The results were
Early-onset cannabis use was moderately associated with later onset of a depression
Of tobacco use they claim
Tobacco smoking and a depression spell after age 16 years were associated too modestly for tobacco to function as an important confounder here
Robust (what a cynic might call the expected “right” result) were seen in Germany, Ukraine, Nigeria, South Africa, and New Zealand, with the strongest associations being seen in South Africa and Nigeria.
Worthy of special note is this observation that:
Estimations for Lebanon, Japan, and China failed because early-onset cannabis use was rare there.
Japan is known to have low levels of cannabis use, China is probably also low, but Lebanon is quite a different situation. In the 90’s (the time period in which the young people studied grew up) Lebanon was emerging from a long and highly destructive war, it is also a major producer of cannabis (hash) and levels of use there are very, very high. Now it could be that the well established social norms of Lebanon work to prevent young people getting stoned, but given the trauma the society went through with the war which only ended in 1990 it would seem unlikely that young people did not come across cannabis very often. Whatever the reason for the data failing there may be, the lack of early onset of use probably wasn’t it.
Persistency of cannabis use into the 12 months prior to assessment did not appear to alter the size of the cannabis-depression association.
Which would seem to suggest that continuing to use didn’t make the problem worse.
Moreover, statistical adjustment for a broad array of precannabis, concurrent, and postcannabis mental health problems in a conditional logistic regression model did little to attenuate the originally observed association
Which would seem to indicate that other mental illness isn’t a factor. So what about the idea that early rule breaking leads to greater social exclusion hence more cannabis use then more depression?
To study the possibility of confounding by a propensity to commit early violations of social norms, we created an index of childhood conduct problems as described in Appendix Table 1 and reestimated the cannabis-depression association with this index in the model, along with terms for age, age squared, and sex. This was possible for all but 4 countries, which did not administer this assessment. Based on data from the 13 countries that administered the childhood conduct problems assessment, and prior to statistical adjustment for this index of early norm violations, the aRR for the estimated cannabis-depression association was modest at 1.18 (95% CI: 1.02, 1.37; P = 0.02). With statistical adjustment for the index of early norm violations, the estimated cannabis-depression association dropped towards the null value and lacked statistical significance
So what do they make of all this?
The general summary evidence from this cross-site research with representation of all world regions suggests that there might be a modest but statistically robust sex- and age-adjusted association linking early-onset cannabis use with later occurrence of a depression spell.
Hardly the clear-cut answer prohibition campaigners would have wanted to read, but it all takes an unexpected turn:
In most prior research on the hazards of cannabis use, the “controls” have been drawn from the total population, without taking into account the fact that in many places cannabis smoking is a violation of social norms.
What they would seem to be talking about is the impact of the legal regime on societies, not the existence or otherwise of some kind of anti-cannabis “social norm”.
Unless early propensity for norm violations of this type can be taken into account, or unless norm violation has no association with the hazards of interest, other research teams may find what has been observed here—namely, an initial statistically robust signal of cannabis-related harm that would disappear when cases and controls were selected with attention to the norm-violation distribution or when the propensity toward norm violation was held constant.
Which would seem to be some comment about the effect of prohibition on the well being of young cannabis users, although it’s phrased in such a way as to be almost incomprehensible.
We found evidence for an association between early cannabis use and later depression spells for 5 individual countries (Germany, Ukraine, Nigeria, South Africa, and New Zealand), representing both developed and developing countries. It is difficult to explain why in some countries the association was significant, while in others it was not. A high prevalence of early cannabis use in a particular country was not a clear explanation for a significant relation. For example, the United States and New Zealand had the highest prevalences of early cannabis use, but only in New Zealand was the association significant. On the contrary, in South Africa and Nigeria, the prevalence of early cannabis use was low, while the aRR was large and significant. It might be that in these countries the deviancy of cannabis use influences the incidence of a later depression spell.
If the deviancy of cannabis use is high anywhere it would be in the USA, also rates of cannabis use in South Africa are also high. However, what this conclusion seems to be saying is that if a correlation exists, it isn’t between the age of onset of cannabis use, but (in some way) it’s deviancy index if such a thing exists. Eventually we get there:
The cannabis-depression association was highest in the oldest age group. This might be explained by the fact that the oldest age group had more time to develop depressive symptoms. Another explanation might be the higher prevalence of cannabis use in younger age cohorts, which makes early cannabis use more normative in younger cohorts and therefore less deviant, with fewer negative consequences (e.g., discrimination, criminalization, use in segregated subcultures), thereby lowering the likelihood of deleterious mental effects such as depressive symptoms. In addition, a shorter duration of cannabis exposure among the younger cohorts could explain this finding, although controlling for persistence of cannabis use in this study did not alter the association.
So what this suggests is that perhaps the more “deviant” – ie the more illegal – the cannabis use of a young person is, the greater the risk of later depression later in life. If you want to study the effects of cannabis use on young people, the effect of the law is a serious confounding issue which should be taken into account.
Now there’s a surprise. Not.
I will soon be publishing my study “Inadequate Research on Cannabis Use and Estimated Risk of Later Onset of Depression in People Reading the Research Report”
…Good point just what level is the burden of proof set at for assessing cannabis objectively? If there is no real evidence of serious health risks for adults then this can be summarised very quickly but padding things out with endless research papers allows everyone to make a quote that suits their own argument. So all new reports become both scientifically and politically correct.
Hum. Please correct me if I have understood wrong, but are the researchers really saying, that if they leave out convenient factors, they might end up with the result they were looking for?
Another badly researched “Report”.Sensible use of cannabis has medical benefits for many people
for whom prescription drugs just do not work.Ask the patients themselves.
I think just as important as the medical benefits is the fact that in the absence of clear cut results that cannabis is highly harmful, it’s a waste of money and time to criminalise millions of otherwise law-abiding people.
One of the methods for those who want things to continue as they are is to maintain an endless debate so that nobody reaches anywhere, just like a dog who chases his tail, there is a lot of effort shown, but no achievement at all. Society is being tricked about this whole issue since the question is clearly to continue things the way they are. There are too many people in high positions that benefit from the prohibition like politicians, police, the justice in general, prisons, corporations etc. who are not interested in the truth. Decades after decades lies have been invented, like “reefer madness” and used to sway ignorant public opinion and after some time shown that they are just lies, surely one day they will run out of lies. In the meantime society suffers the cruel consequence of such stupid policies and irresponsible drug usage increases due to prohibition and not the drug itself. Those who defend prohibition in my country are been called “drug trafficking lobbies” since the only ones who really benefit are the criminals who earn fortunes and drive this corrupt society towards the unhappy situation that looms before us.
P.S. The authorities are much more worried about the vague and uncertain depression and psychosis due to cannabis use than the registered and well known death toll that alcohol and tobacco have on our youngsters (and adults when they grow up). It is like having the authorities fight against traffic violations in a neighborhood while the much more dangerous issue involving the high rates of homicides in the same area is being ignored. These people believe that just because lies are being repeatedly told, they become truths, but they forget that you cannot lie to a great number of people for a long time.
Thanks for the opportunity to give my opinion and keep up the good work
” Tobacco smoking and a depression spell after age 16 years were associated too modestly for tobacco to function as an important confounder here. ”
I wonder if they didn’t overlook the near-universal fact that tobacco is world #1 anti-depression medication and that its principal task is to relieve depression caused by the time interval swince the last $igarette. Because the vast majority of nicotine addicts rigorously maintain their “medication” (at any cost, often L1000’s per year) it’s easy to see how this depression might pass unobserved.
Relevant because in Europe, Morocco etc. for generations so many children have been steered into mixing tobacco into their cannabis. Until recently even the Wikipedia entries for “Cannabis”, “Cannabis (drug)” routinely mentioned this mixing with tobacco as if it were the normal way to use “the drug”.
To add to Jose’s excellent point, not to forget the “people in high positions that benefit from the prohibition like politicians, police, the justice in general, prisons, corporations etc.” are paid out of the tax coffers which are richly amplified by $igarette tax revenues. Corporations? you may ask. Let’s take the famous and beloved Propa & Ganda Company.
1. Folgers Coffee– sells $billions more because of the well-known anti-depressive “synergy” of caffeine and nicotine.
2. Mr. Clean, Spic & Span, Comet Cleanser– needed to clean up $igarette ash litter and filth and remove ‘third-hand” smoke grime from walls, baseboards etc.
3. Secret (alias $igarette?) Deodorant to remove yucky tobacco smells before trying to hug that lady.
4. Wash your mouth out with Scope before trying to kiss…
5. Pringles chips and other hyperspiced $ugarfat junkfoods because tobacco kills your sensitivity to subtler food tastes.
6. “Tide’s in — dirt’s out”– along with smokestink from your clothing after a couple of hours in a smoky card game.
7. P&G has been buying up huge drug companies to profit from all the medications that become necessary after years of slave nicotine addiction have destroyed the victims’ health.
Could go on, there are at least a dozen other “after-profits” from riding the coattails of Big 2WackGo. Obviously a corporation like this sponsors a huge percentage of media broadcasting time in the USA and thus there are guidelines, i.e. newspersons are to say “pot” and “dope” rather than “cannabis” or “herb” when they bring gloating announcements of someone getting Caught with poundages of buds somewhere. Children aren’t likely to see the tobacco industry influence behind it any more than most grownups.
Final word– we are so used to consumer and political apathy we don’t notice what a huge percent of personal time use actually amounts to depression disguised as “relaxation”, “entertainment” etc. Each “depressed” individual is actually “playing it cool” (or do you say school) to avoid blurting out a wrong thought or showing a wrong attitude which will bring on dreaded social penalties up to and including lifetime blacklisting from jobs, money, marriage etc. Much NON-use of cannabis also results from fear that use will liberate “urges” that get one in permanent irremediable trouble. But after use, “a $igarette or two” may suppress (exmedicate) inconvenient urges. The winner: Big 2WackGo.
jose silva – i am having to wirte this on my mobile whilst hill walking. I cannot quote you’re exact statement because opera won’t let me copy and paste or use captial letter at will.
your point about the state trying to prolong the debate, by using full-time think tanks such as state scientists and state intellectuals is true, and is based upon the precedents set by ralph nader, who has the record the changing the most laws, such as the seminal car safety laws he enacted. The state had to make it much more difficult for individuals and very small organistations, who were using debate, to change laws. However, when enough people join a debate, and are passionate, it can have massive influence, such as the debate that enacted propostion 215 in california. The debate in california is still raging, in order to stop the federal government, from using bullish tactics, such as unilateral smash and grab actions – where federal law enforcement smash medicinal marijuana outlets and grab the stock, thus denying some people access to pain relief, such as those who suffer from multiple sclerosis.
The internet allows the public to gain the upper hand in debates such as this. Because it empowers us to work together on a mass scale.
But you have to focus your time on the debates that you are passionate about. Otherwise your efforts become diluted.
I urge you to add to the sticky thread in the activism section of ukcia, started by marianne, about the letter writing campaign. I would like people to post the letters they have sent to their mp’s with the related responses, so that we can see both sides of the debate. Thank you to everyone involved in this debate, you have taught me a lot.
http://en.wikipedia.org/wiki/Ralph_Nader
http://en.wikipedia.org/wiki/California_Proposition_215_(1996)
http://www.bbc.co.uk/news/uk-england-york-north-yorkshire-11305359
Ya I got busted for a joint back in the 70’s as a teenager, got a criminal record and $250 fine, got ostracized at high school, quit to go to work, lost my job, couldn’t get hired, went on welfare, started drinking and smoking cigarettes excessively, became homeless – cooked over a campfire, smelling like smoke at job interviews, bumming food and money from anyone, selling my penis to old men, couldn’t go across the border on vacations with my family, disowned by my Dad (who raped my 3 sisters and physically and mentally abused the rest of our family). So my family doctor says marijuana causes depression, LOL, ironically, and in a round about way I guess he’s right.
I eventually became suicidal and woke up one morning in the nut house. After I got out, I went to AA. Quit drinking and smoking(28 years ago), took up golf and became a self-employed artist. I began using marijuana as a buffer to reduce my anxiety.
I have been married to a wonderful women for 23 years now, have an amazing 10 year old, straight ‘A’ son, own a new car and a van, I’ve been teaching golf now for 16 years, own my own house, and I’m really enjoying life. I Haven’t even had a traffic ticket in 15 years. I Volunteer for 2 charities: cerebral palsy and leukemia.
The only anxiety I get these days is that I fear someday that the cops will knock at my door and catch me with a vaporiser on the go. It’s the best medicine I can get for my inevitable muscle and joint soreness and arthritis that arises from swinging a club all day. One small hit and I’m good for the day. I also don’t drive for a few hours after I medicate. Anyway, I’m trying to get my doctor to give me an authorization for medical marijuana but he says “..it causes depression, here take this NSAID instead..”. I said,”No thanks, I don’t do drugs”.
Good info. I am going to require some time to toy with your content.