No party or night out is ever complete without "that guy" (or girl) making a fool of himself (or herself) by engaging in some sort of booze-fuelled debauchery. If you don’t know who we’re referring to, it’s probably you. However, anyone who can’t hold their liquor may now have an excuse, after a recent study revealed that reckless drunken behavior could in fact be caused by a genetic mutation.
Researchers from the University of Helsinki discovered a link between a mutation affecting the expression of the gene responsible for serotonin 2B receptors and errors in judgement after drinking small amounts of alcohol – including things like getting into fights, having impulsive sex or driving while inebriated. This is caused by a mutation that introduces a stop signal before the gene, preventing it from being read and therefore expressed. As a result, these individuals produce significantly less of the serotonin 2B receptor.
This is one of 14 serotonin receptors in the human body, although according to study co-author Dr. Roope Tikkanen, its function remains poorly understood. The research, which appears in the journal Translational Psychiatry, may therefore have major implications in terms of our understanding of the role of the serotonin 2B receptor, by indicating its involvement in the regulation of impulsive behavior.
While the evidence presented in the new paper relates specifically to reckless antics carried out under the influence of alcohol, the data also suggests that carriers of this mutation are more prone to mood swings and depressive symptoms while sober. It was also found to be four times more prevalent among violent offenders, leading the team to hypothesize the role of serotonin 2B receptors in overall mood regulation and decision-making processes.
The findings contribute to existing theories regarding the role of serotonin in the body, with one previous study finding that the neurotransmitter was responsible for altering subjects’ moral judgement and aversion to harming others. Separate research carried out at Cambridge University, meanwhile, highlighted the ways in which serotonin levels affect the brain’s response to anger.
To collect the data, researchers interviewed 775 Finnish people, who also completed a number of scientifically-approved behavioral and personality questionnaires, in order to discern their level of impulsivity and aggression, both while drunk and while sober. Results showed that the presence of the mutation in question – called HTR2B Q20* – was a reliable predictor of “alcohol-related risk behaviors.” In other words, it’s the exact opposite of the fabled Churchill gene.
While the findings may help to shed light on the role of serotonin 2B receptors across all populations, Tikkanen insists that the mutation has “so far only been found in Finns,” suggesting that not all lightweight drinkers can rely on HTR2B Q20* to excuse their behavior. First identified in 2010, the genetic variation is thought to affect more than 100,000 people in the Nordic country, yet has not spread elsewhere due to the relative isolation of the Finnish gene pool. For instance, according to Tikkanen, the mutation is completely absent from the Hispanic and native British populations, meaning that recklessness while drunk could be a “Finnish national trait.” So if you aren't from Finland and you still can't hold your booze, you probably just need more practice.