You come to a party feeling highly strung and a bit grouchy. Who knows why? It’s just one of those days.

Some idiot notices you’re a bit down in the mouth, and stupidly, carelessly makes a joke at your expense.

Next thing you’re a rumbling volcano. The meatball and napkin that was clutched overly tight in your hand is now spattered against the wall.

Then the idiot says: “Geez mate, take a chill pill.”

If only there was such a pill, right? Who wouldn’t welcome a calming elixir that takes away your anger and aggression and temptation to break a flower pot over the head of one’s tormentors?

New evidence for an old candidate

For more than 40 years researchers have explored the possibility that beta blockers – initially devised to treat certain heart conditions – might be an effective treatment for people with psychiatric conditions or brain injuries who are vulnerable to violent outbursts.

A 1995 review of clinical studies and case reports concluded that beta-blockers “appear to be effective in decreasing the frequency and intensity of aggressive outbursts associated with a wide variety of conditions”.

These studies appear to be confined to clinical in-patient settings.

The most recent evidence for beta-blockers as a preventative against aggression is from a real-world study of 1.4 million people in Sweden.

The researchers – from the University of Oxford and the Karolinska Institute – analysed the violent and self-destructive behaviour of participants when they were taking beta-blocker medication (prescribed for a heart condition) and when they weren’t.

The findings

The study found that:

• The participants had a 13 per cent lower risk of being charged with a violent crime while taking beta-blockers.
• They were 8 per cent less likely to be hospitalised for a psychiatric disorder.
• Those taking beta-blockers were 8 per cent more likely to be treated for suicidal behaviour, but the researchers say “this could also be related to the heart conditions they were managing”.

And that’s one of the issues with beta-blockers research.

One survey found most orchestral players used beta-blockers for their nerves. Photo: Getty

There are many known unknowns, including a poor understanding about how they work to limit violence and aggression. There appears to be little agreement as to what would serve as an effective dose to moderate behaviour.

Even so, the researchers say that if the findings are confirmed by other studies, “Beta-blockers could be considered as a way to manage aggression and hostility in individuals with psychiatric conditions”.

In other words, beta-blockers might graduate from being an essentially experimental treatment for violent outbursts to a more mainstream option.

The many uses of  beta-blockers

The beta-blocker propranolol was first developed in the 1960s as a treatment for angina, the pain or discomfort caused by coronary artery disease.

It was quickly found to be useful in treating hypertension, cardiac arrhythmias and myocardial infarction. It has since been used to treat migraines and, occasionally, glaucoma.

At lower doses it’s commonly used as a remedy for stage fright, a form of social anxiety that features a fast heartbeat, sweaty palms and feelings of tension.

Professional poker players use beta-blockers to keep their cool. Photo: Getty

Propranolol is so effective as a treatment for performance anxiety, some sports have classified beta-blockers as performance-enhancing drugs and banned them.

At higher doses, propranolol has been found to inhibit “rage and anger through its effects on the central nervous system”.

And this is where we get to the nub.

How might they work

Beta-blockers aren’t a sedative or a mood stabliser such as lithium. They operate primarily on the sympathetic nervous system and the heart.

They’re formally known as beta-adrenergic blocking agents, and they prevent the hormone adrenaline from making contact with your heart’s beta receptors.

Adrenaline puts us on high alert when we feel under threat from a car accident or a confronting social situation, for example.

Under threat, when we’re plunged into the ‘fight or flight response’, the heart beats faster and harder.

The beta-blocker causes the heart to slow down a little, and your blood vessels to relax. This tends to reduce your blood pressure and dampens the ‘fight or flight response’, when we could be more prone to lashing out or making a quick exit.

Hence, a potentially aggressive moment runs out of steam, even for people with serious medical issues.

For more about beta-blockers and anxiety, see here.