Last week, I met a GP who suffers from road rage.
"People keep blathering on about how awful it is.
"Well I need it. It's an essential part of my life. It gets out all of my frustration at the end of the day.
"If I don't get the chance to wind down the window and yell 'For God's sake, you bastard' on the way home, I take it out on the wife. It ruins the whole evening.
"But if I've had a good rant, I'm as sweet as pie. I've banged on a few roofs but I've never hit anyone or forced a car off the road. So what's the problem?"
Clearly Dr Bob sees his road rage as some sort of necessary catharsis after an afternoon of heartsinks.
He agrees with Freud that, like wind, aggression is better out than in, and if you don't let rip with your frustrations, they turn inward and you end up profoundly depressed.
I was going to point out that many GPs end up profoundly depressed whether they exhibit road rage or not, but as we were nose to tail with a Landrover Discovery at the time, and he was about to unleash a stream of well-chosen venom, I decided to let it lie.
Just lately, I've been encouraging Bob to develop a sense of humour.
Freud was a fraud, but he also thought that satire was a socially acceptable sublimation of aggression. So why not just take the piss?
I have also encouraged him to read the research. There's no evidence that expending your aggression in a car (or anywhere else) makes you any less aggressive when you've finished. On the contrary, aggression just seems to breed more aggression.
Those who indulge in contact sports exhibit far more daily aggression in season than out of it. The reason they find it cathartic is not that legally controlled violence makes you mellow afterwards – it doesn't – but simply that they enjoy being aggressive.
Bob wasn't convinced, but he did admit that he got a kick out of raging. And he'd already tried anger management.
"A drug rep gave me a relaxation tape and I fell asleep at the wheel. What else is there? Pull into a lay-by and listen to Radio 3? No thank you."
But what if the person he rages at turns out to be one of his patients? With a heart condition? And it pushes him over the edge and kills him?
"It's pretty unlikely, don't you think?
"I mean if they're that fragile, they shouldn't be driving.
"Anyway, I try not to rage on my own patch. And I'm getting tinted glass put in, so I hope I won't be recognised."
"But then people won't see you being angry either, so what's the point?"
"I hadn't thought of that."
I was about to give Bob up as a lost cause, but then I found a brilliant solution in my black bag – artificial saliva, available over the counter for people without much real saliva.
Its great for public speaking, when one end of your gut goes dry and the other end goes moist. When you squirt it on your tongue it actually tastes like someone's spat in your mouth.
But best of all, you can keep it in the glove compartment for when someone cuts you up.
Instead of ramming them or swearing or doing anything that might reflect badly on the profession, Bob now calmly lowers his window and fires off a few squirts, without a hint of anger.
Virtual gobbing – you know it makes sense.
- Dr Phil Hammond is a GP and author of Trust Me, I'm a Doctor (Metro, £9.99).