Monday, 28 October 2013

You Only Live Once

This post was written by Natasha Clarke for her own blog, the original is here

As a break to celebrate the end of my Masters, I spent six weeks of my summer in Lake Bled, Slovenia. This is a small and picturesque town, and is also part of the route that many interrailers take. Thus the trip involved a fair amount of bar crawls, and due to this I saw many sights that will stay with me forever. I witnessed a topless primary school teacher parading barefoot on a dance floor covered in smashed glasses. I saw three Kiwis having a group sick session in the same bin. There were also a fair few drunken fights and midnight dips in the lake. Some nights I swear I could have been in Malia.

One night I heard a cross eyed, swaying interrailer slur “YOLO” as he polished off his 10th shot of the local 30% pelinkovak. Now unless you have been cooped up in a cell with no access to television, radio or any form of social media for the past few years then I am sure the majority of you will have heard the phrase YOLO. Wikipedia says it “implies that one should enjoy life, even if it entails taking risks”. Urban Dictionary describes it as “the dumbass’s excuse for something stupid that they did. Also one of the most annoying abbreviations ever…”. Regardless of which definition one might agree with, it’s an excuse for partaking in behaviour that may be dangerous, and is one that is frequently used amongst young people when it comes to drinking.

Holidays are a time when this phrase will be used frequently, a period when young people are known to take the greatest risk with their health, and every parent dreads the day their teenager utters the numbers 18 and 30. These getaways don’t involve culture and local delicacies; in fact they’re a breed of holiday that should come with a new liver as part of the package. A recent survey of British holidaymakers travelling to Majorca and Ibiza found that over half of participants were intoxicated five or more times and 90% got drunk at least once. Fair enough, everyone likes a few cocktails on the beach, but it’s the dangers associated with this drinking that prove worrying. For instance, 11.6% of those visiting Majorca were involved in a fight, and just over a quarter in both destinations had sex, with a third of individuals not using a condom. Another study with British, German and Spanish holidaymakers in the Balearics supported the finding that heavy drinking is associated with risky sexual behaviour. So not only do you come home with a hefty hangover, but there’s also a high chance you’ll bring back a broken nose and chlamydia.

It’s not just the likes of Malia, Kavos and Ibiza that are associated with heavy drinking. A study on excessive alcohol behaviour in Cusco, Peru, found that in a sample of American, British and Spanish tourists over half of the travellers had consumed alcohol between 50% and 100% of the days they were there. Single males below the age of 26 were most likely to get drunk and this drinking was associated with drug use, sexually transmitted infections and increased illness impact. Furthermore, it’s been found that UK residents show a significant increase in the frequency of alcohol consumption when backpacking in Australia, with those drinking over 5 times a week rising from 20.7% at home, to 40.3% when away. With alcohol use in the UK already at a worrying level, this is a shocking reminder that when out of our home residence, our behaviour with alcohol seems to get worse. It’s worth noting that many of these trips abroad will not just be a week long, they could be a month, or a year. That’s a significant proportion of our year (or the whole of it!), that seems to be emitted from real life behaviour, and many hold the view that the behaviour carried out somewhere new and exciting doesn’t count (or I should I use the phrase “what happens in [insert country], stays in [insert country]”).

It’s a common attitude in young adults that the risks associated with heavy drinking are not applicable at such a young age, particularly the long-term health risks. This is a misconception that may be even further emphasised when travelling. Unfortunately we’re not invincible just because we’re young and off home soil. Although the major health risks with young people are those associated with accidents and injuries, the number of deaths in 25-34 year olds due to chronic liver disease and cirrhosis has steadily risen in England over the past 30 years. The younger we begin heavy drinking, the earlier we see chronic health problems associated with this excess behaviour. It has been suggested that beyond an average consumption of 10g/day (1 unit), our absolute risk of death from an alcohol related condition increases with increasing alcohol consumption. Therefore the more drinking occasions we have throughout our life, at both a young age and an older age, the higher our risk. It’s not only long term health implications we are vulnerable to, during intoxication our blood pressure is raised, and when the alcohol wears off, it falls below the normal level. These changes can increase the likelihood of strokes; therefore showing the effect bingeing can have on the heart.  

This indicates alcohol related harm is still relevant when we are young, and we may be particularly at risk when we are away, but research is sparse and little information is available on British holidaymakers’ alcohol consumption. For researchers, it’s important to note that when looking at long term alcohol consumption, much self-report data will not take into account the amount that is consumed on holiday, and furthermore on special occasions such as birthdays, Christmas, weddings. These are times when our attitudes and behaviour may be similar to when travelling. A substantial proportion of the year drinking may be unaccounted for, and this is supported by recent data showing that self-reported consumption by the UK population and alcohol sales do not match up.

Obviously the last thing I want to do is ruin any fun, and we all want to enjoy ourselves when we’re relaxing abroad, but there are things we could do to reduce the dangers. One option is travelling to a country that doesn’t centre around drinking, when I went to Morocco last year I hardly drank a drop (mostly due to the fact we couldn’t find it anywhere), and it was just as enjoyable as the holidays where I have spent the majority of my time in a bar. In fact, it was better as I remembered every last detail; the drunken photos weren’t the only reminder. But if we are going somewhere we know involves local shots and fishbowls, it’s important to be aware of the potential risks associated with alcohol and measures that can be taken to reduce the risks. Current media attention is attempting to increase our awareness of these dangers and has focused on some of the serious issues surrounding our excessive and carefree attitude. A recent example is “Old Before Our Time”, a documentary on chronic conditions in young people caused by excess drinking at an early age. It’s a hard hitting and eye opening reminder that young people are not immune to the damage alcohol can do. So I return to the phrase “YOLO”, you only live once, surely that’s even more the reason not to ruin it with excessive drinking?  

Saturday, 26 October 2013

Mixed effectiveness of population-level interventions to reduce alcohol consumption and harm

This post was written by Matt Field for the Mental Elf, you can find the original here.

Alcohol is responsible for approximately 2.5 million deaths worldwide every year, making it the third largest cause of preventable death after tobacco and obesity. The economic burden to the UK has been estimated in the region of £20 billion per year, comprising the NHS bill, costs to employers and policing costs amongst other things. Reducing harmful use of alcohol is therefore a top priority, and there are two broad ways that this can be achieved. Individual interventions focus on the individual and include things such as medical treatment of people with alcoholism, and brief interventions delivered to young people in healthcare settings. Whereas population interventions are targeted much more broadly, and they aim to reduce alcohol consumption and harms in the population as a whole.

A recent review published in Preventive Medicine investigated the effectiveness of population-level interventions to reduce alcohol consumption and associated harms such as drink-driving and alcohol-related violence. The authors found that overall these interventions were effective but, as always, the devil is in the detail.

What did they do?

This is a narrative review of previously published systematic reviews published from 2002 onwards. They identified 52 primary reviews, and rated them for quality. Twelve were rated as high quality, 29 as medium and 11 as low quality.  Most of the primary studies were conducted in North America, Northern Europe and Australasia.

A diverse range of interventions were considered, some examples of which are listed below (this is not an exhaustive list!):  

  • Availability – for example policies that restrict opening hours or alcohol outlet density
  • Taxation – for example increasing taxes on alcoholic drinks
  • Mass media – for example, health promotion campaigns or restrictions on alcohol advertising
  • Drink-driving – for example police checkpoints and random breathalysing
  • School interventions – for example extra-curricular programmes
  • Higher education interventions – for example alcohol-free accommodation.

After grouping the interventions in this way, the authors performed a narrative review of the systematic reviews.

What did they find?

There was some evidence for the effectiveness of all of the different types of interventions that were studied, although the consistency and quality of the evidence was highly variable.  A general observation was that there was more consistent support for regulatory or statutory enforcement interventions as opposed to local, non-regulatory approaches that targeted particular groups of individuals.

  • The following types of interventions were consistently supported, amongst others:

    •  Restricting days or hours of sale
    • Reducing alcohol outlet density
    • Minimum drinking ages
    • Drink-driving checkpoints and patrols
    • Mass media campaigns
    • Increased taxation

  • Other interventions had mixed or weaker support: 

    • Server-training
    • School-based interventions
    • Family-based interventions
    • Workplace-based  interventions
    • Restrictions on alcohol advertising, amongst others

  • Higher education interventions were consistently shown to be ineffective

  • Whereas a long list of other interventions had insufficient evidence to allow a firm conclusion to be reached, some examples include toughened glassware, and promotion of designated driver schemes


The findings from this paper are consistent with two similar reviews published in 2010. Therefore, for people familiar with those earlier reviews, the main take-home message is that nothing much has changed in the previous three years.  

The authors noted the

greater pattern of support from the evidence base for regulatory or statutory enforcement interventions over local non-regulatory approaches targeting specific population groups

This can be seen as good news or bad news, depending on your point of view. Regulatory or statutory interventions (such as tax rises) normally need to be instituted at the national or federal level, which means that not much can be done at the local level. It would take a brave government to introduce some of the more controversial policies, such as minimum unit pricing, and local authorities are powerless to introduce such changes on their own, even if they might want to. Even where local authorities do have the power to change things or introduce new policies (for example attempts to control of the density of alcohol sales outlets), these are often challenged by conflicting regulations.


Given the diversity of interventions that were considered, you might wonder if this is a case of “noise in equals noise out”. The authors were aware of this risk, and they comment that any bias that is present in primary studies is compounded by additional layers of bias at the systematic review stage, and a further layer of bias at the next stage of summarizing all of those systematic reviews. However, the authors did their best to mitigate against this, by coding the systematic reviews for quality and plotting the consistency of evidence in different domains.

The authors also noted that some more recent population-level interventions, such as minimum unit pricing, could not be considered because there were not enough primary studies to warrant a systematic review of their effectiveness. Therefore, this kind of uber-review really needs to be repeated every few years, in order to capture the effectiveness of novel interventions.

Link to paper: 

Martineau F, Tyner E, Lorenc T, Petticrew M, Lock K (2013) Population-level interventions to reduce alcohol-related harm: an overview of systematic reviews. Preventive Medicine, 57, 278-296. 

 on twitter

Thursday, 24 October 2013

Meth: I choose you! Does study show addicts' choices are ultimately rational?

This post is a slightly modified version of one that was written by Jay Duckworth and posted on his own blog

Last month (16/09/13) The New York Times published an article in their science section entitled The Rational Choices of Crack Addicts, which was promoted online by numerous sources and proved to be quite popular. Incidentally, this popularity is evidenced by the numerous iterations of the original piece in various media outlets (some of which can be seen here, here, here, here, here, here and here). The version published in The Atlantic further enjoyed a promotional tweet by the famous Harvard psychologist Steven Pinker:

The Science of Choice in Addiction - Sally Satel - The Atlantic
— Steven Pinker October 2, 2013
The articles possess the same basic implication - that the predominant view of addicts as zombie-like creatures bound by their compulsion is wrong, and now we have evidence to prove it. The problem with this, however, is two-fold: first, the view outlined above is not the predominant view of most addiction researchers, but a caricatured version of a more measured and nuanced conception (Marc Lewis's description of addiction as "biased choice" succinctly parses this quite well; he also has a piece tackling a similar subject to this post). The second part of the problem is that the conclusions of many of the media outlets vastly exaggerate the reach of the study they cite.

The study in question is that of Kirkpatrick et al. (2012): Comparison of intranasal methamphetamine and d-amphetamine self-administration by humans - a title rendered sufficiently bland by its competitors in the media (Gawker's headline was Why Everything You Know about Crack Addiction is Wrong). The study's primary aims were to test the effects of different molecular amphetamines on cardiovascular health and psychomotor performance, as well as users' subjective experiences (i.e. ratings of mood change and behaviour towards each drug).

The general procedure (of interest here) was as follows; participants were subjected to two different sessions on two different days - the first was a "sample" session in which participants were provided with samples of both drug and monetary rewards; the second a "choice" session wherein these rewards were actively chosen by participants during a computerised task. Depending on their choices, participants received either some ratio of drugs and money, or maximal amounts of either reward. Participants were also assigned to either a high value condition or low value condition; those in the former received $20 on sample days and had the option of obtaining $20 on choice days (given they chose only monetary options during the task), while those unfortunate enough to be assigned to the latter condition received only $5. (Drug doses were the same for each condition.)

It was found that those in the $5 condition possessed no strong preference for a single reward, with only a slight choice tendency towards the money (59%). Those in the $20 condition, however, were far more likely to choose money over drugs, with 83% of options chosen being monetary. The authors concluded that when given a valuable-enough alternative, participants could be dissuaded from drug self-administration: a reasonable conclusion. The media then took this modest hatchback of a conclusion and inflated it to Ferrari-like proportions. The labelling of the media's conclusions as exaggerated is justified for two reasons: first, such significant conclusions are unlikely to ever be validated by a single study (this, as a rule, is not how science generally works). Second, such conclusions based on this particular study would be unwise given its numerous limitations.

We can first consider flaws with the study's cohort. With just 13 participants, the study's sample size was small; but further, since the design was between subjects (meaning conditions are effectively analysed separately) this reduces the numbers further to just 6 and 7 participants in each condition. These numbers are minuscule. Moreover, all participants were male and self-selected - none had ever sought help for their drug use nor were they interested in receiving any - meaning that what we might have here is a particular subgroup of drug users with different goals, intentions, personalities and experiences with drugs, which do not apply to many others not in this group. Furthermore, the authors note that only three of the participants met the criteria for drug dependence - this is only 23% of an already tiny sample! Overall this means that any conclusions derived from this study cannot simply be extrapolated to clinical populations.

There also exist problems with the study's design (given the conclusions of the media). Since participants were automatically supplied with drugs on "sample" days, we cannot make any solid deductions about whether the same results would be garnered in periods of abstinence. Also, given that many of the participants may have been occasional users, a hit of meth every few days may have been ample, meaning the only real option to go for would have been money anyway. This also means that the employed strategy of many may have been to sequester funds for purchase of drugs after the experiment was over. However, this is unlikely to have been the case - at least if the plan was to spend the monetary rewards on meth. The values of the drug and monetary rewards over the course of the study were well matched ($60-$80 and $100, respectively), and given the average dose of meth (250mg) will set you back around $80 on the streets of New York (the study's location), the participants would receive the same amounts of meth whether they obtained it from the researchers during the study or from Walter White afterwards (Breaking Bad references are still going strong, right?).

However, another small problem appears when we consider that these participants were also users of cocaine and marijuana, both of which are cheaper than meth (marijuana substantially so; see Table 1).
Illicit drugs prices in New York City: 1lb
~$2,000 - $3,000
Table 1: The links for these estimates can be found in the reference section.

This means that the above strategy would still be valid when applied to these other drugs, and so again any inference that these results alone show the way forward in how we treat addicts is mistaken. Finally, the doses used in this study were 5-20 times lower than average street use, and simply scaling these results upward and assuming they would remain the same is bad practice.

So as we can see, though this is by no means the worst study you're likely to find, the conclusions made by the media extended far beyond the study's grasp. This is a shame, not just because scientific research has been misrepresented - though this would surely be enough - but also because there are other studies out there which actually test whether alternative monetary reinforcers dissuade addicts' drug inclinations, and they support the results found here. Some might ask "Then why write this article?!" But to ask this question would be to miss the point. The point here is not to say that offering alternative reinforcers to addicts could never work, but to highlight the fact that this lone study could never provide the evidence necessary to show that it does. In the progress of science, evidence is more often than not carefully accumulated, not acquired in its entirety. The media would do well to remember this.


Hser, Y. I., Huang, D., Brecht, M. L., Li, L., & Evans, E. (2008). Contrasting trajectories in Heroin, Cocaine and Methamphetamine use. Journal of Addictive Diseases, 27, 13-21.

Kirkpatrick, M. G., Gunderson, E. W., Johanson, C., Levin, F. R., Foltin, R. W., & Hart, C. L. (2012). Comparison of intranasal methamphetamine and d-amphetamine self-administration by humans. Addiction, 107(4), 783-791.