Alcohol: Effects on Teenage Brains and Correlations Between Availability and Violence
I’ve written previously about the effects of alcohol on decision making. Today I’ll be looking at two further aspects of alcohol consumption and how it affects society. First up is a study that examines the cognitive effects of moderate to heavy drinking during adolescence, with different effects on males versus females. Secondly I’d like to cover an interesting paper that relates the amount of violence in a community to the number alcohol outlets in the community.
There is an interesting contrast between the two papers, one focusing on the effects of alcohol on the individual and possible long term effects and the other on the wider community. Like tobacco the use of alcohol is coming under increased scrutiny in our society and this is a good thing. The difficult part in both processes is to ensure our actions are guided by evidence rather than knee jerk emotion. Smokers complain that they are unfairly victimised when alcohol causes so much harm, this may be true but it is irrelevant to the discussion of the harms of tobacco use. The same is true from the alcohol side of the debate.
Each substance must be approached and dealt with on it’s own merits and derailing the discussion to decry the abuse of one or the other is unhelpful. I am not an expert on public policy and do not advocate any particular solution to either of these issues, I don’t know what the best solution is but it is tiresome to see the same diversionary tactics arise time and again in these sorts of debates. With that, lets move on to the science.
The first paper, “Initiating moderate to heavy alcohol use predicts changes in neuropsychological functioning for adolescent girls and boys“, follows a cohort of 76 adolescents starting at ages 12-14 years. The participants of the study were chosen to limit the amount of exposure at baseline to addictive/mind altering substances. These individuals were then followed over approximately 3 years and given a battery of tests and questionnaires to determine their drinking habits and cognitive abilities.
As we might expect heavier drinking patterns in the adolescents predicted poorer test results. The interesting result is the differences in the effects of the alcohol in male versus female subjects.
Female subjects that consumed higher amounts of alcohol in the preceding 12 months performed worse on tests of visuospatial functioning than the control group. One of the ways this was measured was using something called the Rey-Osterrieth Complex Figure test (see pic), this entails the subject copying the figure, and then drawing it again some interval of time later (in this case 30 mins) from memory.
The number of drinks required to see this effect appeared to be 12 or more a month (in the previous 3 months), with the larger doses leading to a more pronounced detriment. Of course this was a trend effect in a population, on average heavier drinking females did worse in these tests but any one female was not guaranteed to see a reduction in performance.
Males on the other hand tended to do worse in the attention tests. Going by this measure I’m sure wives the world over would swear their husbands had been habitual binge drinkers throughout adolescence. The test of sustained attention in this case was done by the Digit Vigilance Test, this simple test consists of rows of single digit numbers printed in either red or blue (single colour per page). Subjects must find either 6s or 9s on each page.
By timing the task and counting the errors committed a measure of sustained attention can be determined and compared to the control group.
A drawback of this work is that the number of subject was limited, the entire study had a total of 76 adolescents, of those 29 were female (leaving 47 males). These groups then had to be further bisected to give the drinking and control groups. This study was quite small but is consistent with previous research showing negative effect on the brain for developing individuals. The bottom line of research like this is not difficult to get to, there are detrimental effects to be had by allowing young people to indulging moderate to heavy alcohol consumption. What we do with this information is up to us.
The second paper was presented by William Pridemore and Tony Grubesic at the annual meeting of the American Association for the Advancement of Science in San Diego earlier this year. With the engaging title of “Alcohol outlets and community levels of interpersonal violence: Spatial density, type of outlet, and seriousness of assault” the paper examines the correlation between the number of places where alcohol is available in a community and the amount of violence the community experiences.
I think we can all guess the outcome but it’s nice to have actual data to back up our intuitions. The study was quite detailed in it’s approach with the violence broken down by simple assault and aggravated assault and the type of alcohol outlets subdivided into bars, restaurants and so-called “off-premise” outlets where alcohol is sold but not consumed on site, such as supermarkets and liquor stores.
It comes as no real surprise that a higher density of alcohol outlets was correlated with a higher level of violence in the area. A result that I did not expect though was the significant effect the “off=premise” alcohol outlets appear to have on the levels of violence in the area. The study estimated such sites contribute between 25%-30% of the violence (depending on the category) of an area. This compares to approximately 10% each for bars and restaurants.
The reason for this difference is suggested to be that these areas can act as impromptu gathering places where it is perceived that the normal rules of society do not apply, especially if the area is unkempt in appearance. In such areas individuals may have an altered perception of the moral expectations and this coupled with the disinhibiting effects of alcohol could lead to the greater propensity for violence.
Once again the information may merely inform our decisions not make them for us. Is the best approach simply to limit the number of alcohol outlets, or ban then from some areas altogether (or completely?). Or should we use this information to put measures into place to reduce violence while retaining access to alcohol, perhaps by creating environments around outlets that are less conducive to violent confrontations. Maybe some nice waterfalls and soothing music would help, I’m sure I have an Enya CD around here somewhere I could donate to the cause (or possibly The Corrs).
Squeglia, L., Spadoni, A., Infante, M., Myers, M., & Tapert, S. (2009). Initiating moderate to heavy alcohol use predicts changes in neuropsychological functioning for adolescent girls and boys. Psychology of Addictive Behaviors, 23 (4), 715-722 DOI: 10.1037/a0016516