Disclaimer: This post is about how alcohol interferes with memory formation and how that can be paradoxically beneficial under very special circumstances. Think of the plot of Eternal Sunshine of the Spotless Mind, you’ll get the idea. It’s not a license to get drunk. Jeeze.

Well-meaning friends and family members may suggest that you have a couple of drinks after living through a stressful event. A friend of mine had a bike accident recently that sent her over a car door and miraculously left her with only a few bruises. Having a couple of drinks immediately after this will of course dull her nerves, since ethanol is an anxiolytic. But is it really a good idea to get tipsy (or worse) after living through a stressful event?

lt’s well known that acute stress modulates memory in a powerful way. People who have lived through a traumatic event will often either have either perfect photographic memory of the event or partial or total amnesia. Untreated, exposure to a traumatic event can lead to post-traumatic stress disorder (PTSD), which causes long-term problems. There exist preventive treatments that, when applied immediately after the traumatic event, have been shown to decrease the likelihood of getting PTSD. This includes antagonists of adrenaline and NMDA receptors; this messes with the acquisition of memory.

Of course good ol’ beer will mess with the acquisition of memory; that’s why people get brownouts and blackouts. It is also an antagonist of NMDA receptors (among many other systemic effects). So given that alcohol is an anxiolytic and that it causes amnesia, it doesn’t seem such a stretch to think that having a beer right after very a stressful event (within the next, say, 6 hours) will decrease the likelihood of long-term negative consequences (say, developing a phobia of biking).

This is of course the sort of hypothesis that is very hard to get funding to test. We do know that PTSD sufferers frequently turn to alcohol after their trauma and that this negatively affects outcome. And drowning your sorrows is never the solution. To be clear, taking an anxiolytic and amnesiac acutely to avoid acquiring a potentially adverse memory of a traumatic event and taking it in a sustained way after the memory is consolidated to drown it out are two completely different things.

We have to turn to (extremely unfortunate) natural experiments to see whether this idea is actually worth pursuing. Maes. et al (2001) describe the results of interviewing a cohort of 127 people 7-9 months after being trapped in a ballroom fire. Some of these people had been sober during the event, some were tipsy, and some intoxicated (drunk). Some developed PTSD, some didn’t. The relative risk of getting PTSD after such an event was .42 for people who were tipsy compared to those who were sober (confidence interval: 0.20-0.87) after controlling for other factors such as age and gender. For people who were frankly intoxicated, this was .22 (CI: 0.07-0.70). In layman’s terms, being drunk during a traumatic event decreases 5-fold the risk that you will develop PSTD (although the error bars are large, so the apparent magnitude of the effect cannot be relied on).

Whether this research on PTSD is relevant to the issue of long-term emotional outcomes in non-traumatizing, but nevertheless very stressful events is unclear. For one, while factors like sex and previous experience of trauma were controlled for, they are likely to be correlated with drunkenness, and that makes it difficult to conclude in an absolute manner whether that it is really the alcohol that’s the culprit: women are much more likely to be affected by PTSD (by something like 5-fold), as are people who’ve already lived through trauma (again by about a 5-fold factor, and rape is both traumatizing and much more likely to be experienced by women than by men). Of course, women have different drinking patterns than men on average; so we get back the same issue that we get in all natural experiments, namely, everything’s correlated with everything.

So this research is non-conclusive, and the jury’s still out about whether having a peri-traumatic drink is a good idea. But it makes some amount of sense, and I’d be curious to see follow-up research on this subject (although, again, due to obvious funding and ethical issues, I won’t hold my breath).

Maes M, Delmeire L, Mylle J, & Altamura C (2001). Risk and preventive factors of post-traumatic stress disorder (PTSD): alcohol consumption and intoxication prior to a traumatic event diminishes the relative risk to develop PTSD in response to that trauma. Journal of affective disorders, 63 (1-3), 113-21 PMID: 11246087