By Christian Jarrett

I confess, I’ve tried having an alcoholic drink before giving a public speech, telling myself that it will take the edge off my nerves. But I’m going to think twice before doing so again: a new study in Behaviour Research and Therapy carefully monitored the effects of moderate alcohol intake on the speech-giving performance of socially anxious and control participants and while the alcohol made the nervous folk feel more relaxed, it actually harmed their performance.

Stephan Stevens and his colleagues recruited 99 young adults who met the criteria for social anxiety disorder and 78 non-anxious controls, and then allocated them randomly to one of three conditions: an alcohol group drank three vodka orange juices with the strength adjusted to their body weight to ensure they reached a blood alcohol concentration of 0.07 per cent (for comparison, the drink drive limit in England and Wales and Northern Ireland is 0.08, ditto for the USA, while it’s 0.05 in Scotland); a placebo group who thought the orange juice they were drinking had vodka in it; and a baseline group who knew they were drinking pure orange juice. The participants reported how anxious they were feeling before, during and after delivering a three-minute speech on the death penalty in front of an audience of two.

The socially anxious participants who drank alcohol felt less nervous during the speech and afterwards, as compared with anxious participants in the placebo group and in the baseline pure-orange group. This gives an indication of why alcohol can become a crutch for so many anxious people with rates of problem drinking being much higher than average among people with anxiety diagnoses. Looking on the bright side, given that excessive anxiety can hamper performance, you’d think the calming effects of the alcohol might have aided the performance of the socially anxious participants.

But that’s not what the researchers found.

Drinking alcohol actually led to socially anxious participants’ speeches being rated worse by two scorers who didn’t know which participants had a social anxiety diagnosis, nor who had drunk alcohol. The scorers also gave poor ratings to the speeches given by non-anxious control participants who’d drunk alcohol (for this group, there was no calming effect of alcohol, perhaps because they didn’t find the speech particularly nerve-wracking anyway). These findings suggest that even a couple of drinks is intoxicating enough to interfere with the mental processes needed to deliver an effective speech.

As for the socially anxious participants in the placebo condition, they felt less nervous than the baseline group who knew they’d drunk pure orange juice, but more nervous than alcohol group, suggesting that the calming effects of alcohol are partly pharmacological and partly to do with expectations. Participants in the placebo condition also gave worse speeches than those in the baseline condition, but not as poor as those in the alcohol condition.

Stevens and his colleagues said the performance-harming effect of alcohol could lead to a vicious circle: anxious people drink alcohol to calm their nerves, but it interferes with their speech-giving performance, so they get more negative feedback than they would have done sober, and then they’re even more nervous about the next time they have to give a speech, which only makes them want to drink again.

The researchers noted that alcohol might have different effects on the social performance of anxious participants in different kinds of contexts, such as chatting at a party or at a meal.

—Feeling safe but appearing anxious: Differential effects of alcohol on anxiety and social performance in individuals with social anxiety disorder