The characters seemed a little two dimensional and transparent in places.

For a long while, every time I filled the kettle with cold water first thing in the morning I thought I heard someone upstairs scream. I wondered at the time whether this might be an interesting kind of hallucination.

A ‘functional hallucination’ is a false perception that occurs at exactly the same time as a real perception, such as the sound of running water. I had assumed till then it only occurred in old German text books and multiple choice exam questions.

It turned out there was a more mundane explanation. The reduction in water pressure caused by turning on the kitchen tap caused the person having a shower elsewhere in the house to experience a sudden water temperature change, first quickly upwards followed by quickly down. The culprit was and still is a poorly operating thermostatic mechanism in the shower unit.

Although the shower over-reacted in terms of temperature control, I am careful to state that the showering person reacted completely appropriately.

The thermostat is our basic model of a feedback system. It senses the temperature of the water. If the temperature goes too hot or too cold, it responds by cutting or increasing the power to the heating element.

The same sort of negative feedback system occurs in most devices, throughout our bodies, and more generally through social systems.

It requires two prongs – a sensing device, and a device that effects a change.

When we come to try and understand the word ‘dysfunctional,’ that seems to describe certain behaviours or relationships – sometimes even applied to an individual – most often we are looking at a faulty feedback mechanism.

In British culture we have a great deal of trouble knowing how to react to things. For instance, it seems the height of bad manners to criticise someone directly. That would be like sounding a car horn. Instead, we tend to use a low key grumbling approach via third parties – like trip advisor, or writing a rude letter and not sending it.

There are a few exceptions, such as talent shows, and the army. If you want a more challenging annual appraisal, perhaps Alex Ferguson would oblige, using his famous ‘hairdryer method’.

But in general it is very difficult to get honest feedback.

If you write a reference for someone who is absolutely terrible at their job, the custom is to write a glowing reference with the tiniest hint of faint praise, e.g. ‘may lack ultimate commitment’.

One guide to how to behave in a crisis is watching drama. Millions watch soaps like Eastenders on a regular basis. How far do people model their social behaviour on such programs?

Whereas stage actors tend to exaggerate voice and gesture, movie actors have to play it deadpan. TV is somewhere in between, perhaps to do with the size of the actors face relative to real life. If shows get made specially to be viewed on a smartphone, they will probably star Brian Blessed.

Like actors in Greek tragedy, people with Depression tend to ‘catastrophise’ in reaction to events. Odysseus’s mother apparently committed suicide after hearing flimsy evidence that he had died.

In drama, Greek or Soap, no-one ever responds to a crisis by calling a helpline.

British people are more likely to under-react to a crisis. David Beckham found out one of his tattoos had misspelt the word Victoria, written in Sandskrit, as Vichtoria. History records that he was not unduly concerned, merely resolving to stick to Latin for further etchings.

A gentleman with OCD I used to know told me this story. One day he had taken his long suffering ‘good lady’ to the seaside, leaving early to avoid the traffic. Having driven 120 miles to the coast, he was confronted by a completely empty car park with hundreds of spaces. He drove around several times, unable to choose a space and eventually had a panic attack. After recovering, and still not in a parking space, he drove home again.

‘I’ve been a bit silly again’, he finally told me.

I should perhaps have anticipated this kind of eventuality and suggested a simple algorithm for parking. Recently I discovered that elevator systems in large buildings have just such a system for deciding which lifts should go to each floor.

Apparently, according to Mitsubishi Electric, a person becomes irritated immediately he presses the lift button and nothing happens. However, the level of irritation is proportional to the square of the waiting time. From this we can begin to understand how people can develop rage attacks surprisingly quickly.

Remember Christian Bale’s outburst on the set of Terminator? Apparently a technician walked across his sightline during a scene.

I know the feeling, from trying to talk to acutely psychotic patients in the same hospital room where builders are operating pneumatic drills and ripping up the lino with Stanley knives.

There are a number of ways to explain why certain people seem to ‘lose it’, experiencing an acute change in mood and behaviour.

Steve Peters would call it ‘letting the chimp out’, meaning a switch in mind-set, allowing a different set of brain pathways to take over control. Thankfully, Mitsubishi have not included a Chimp Mode in their elevator systems. Though Beko appear to have included a ‘Surrealist Mode’ in their washing machines.

A more neuroscience-based model still, is the possibility of positive feedback, or kindling, where the response actually goes the opposite way from restoring the norm. This is often called a vicious circle.

One theory of panic attacks uses a vicious circle model, where mild signals of distress from around the body are over-read, cause anxiety and thus further physical distress signalling, such as breathlessness, palpitations or chest pain. Finishing with a slightly embarrassing visit to the coronary care unit.

A behaviourist could explain ‘losing it’ in terms of social learning. Previous tantrums or losses of control have been rewarded by parents or others, either in terms of letting the upset person have his way, or by way of reducing ‘messing’ with that person. Having a ‘short fuse’ can be quite useful in certain situations. I once worked for a consultant who was completely benign 99% of the time, but the word about him was, ‘watch out, he goes berserk every now and again’.

One of the triggers seemed to be handing him a post it note with a poorly worded or scribbled message and a phone number. It was not that he had been hypnotised previously and made to react this way, although this is possible, knowing the hospital involved.

It was just that being handed a post it note is a metaphor for being handed a problem, but without the information needed to act on it properly.

I’d like to think that his reputation would have worked to reduce the number of post it notes he got handed, but I never saw any sign of this. Post it notes continued to flow like confetti. Perhaps he should have set fire to them immediately or eaten them.

In the NHS, feedback loops operate comparatively slowly, so it would have taken about 20 years to see the post it notes’ eventual downturn.

Remember the film, ‘Falling Down’? Here, the character, D Fens, is played by Michael Douglas, who is a screen actor and therefore tends to play deadpan. D Fens progressively loses it after a ‘rare morning’, ending up in a spree of violence across LA. The trigger event appears to be a shopkeeper refusing to give change.

An older theory of ‘losing it’ relied on the notion of a repressed or over-controlled person, which I think is what the director had in mind. D Fens had seemingly suppressed his anger by being extremely tidy and organised, never allowing himself to become emotional, and therefore never setting appropriate limits on people.

Here I suppose the systems analogy is the pressure cooker. This has a very primitive feedback loop, so that a massive degree of change from steady state is needed before the feedback occurs, in the form of opening a safety valve.

Here the feedback loop is too coarse to make rapid enough corrections, necessitating an external over-correction, such as being gunned down, albeit reluctantly, by Robert Duvall.

CBT is designed to improve a person’s feedback system: on the cognitive side to make sure the right information is collected; and on the behavioural side to make the appropriate responses.

Luckily the government has given us a new way to make sure we react appropriately.

We’ve been used to making a 999 call, for moments where we identified a very serious crisis. However, the 999 system is abused on a daily basis. One of the problems is that TV never shows anyone calling a helpline appropriately, so we don’t know what constitutes a 999 level emergency.

People have rung 999, for instance, to ask ‘how to dial 111’; because they were not being served in Macdonald’s; to try and obtain a laptop password, and to report the theft of parts of a snowman.

Now, to create a kind of crisis scale, at the milder end, we also have the 111 call.

That gives us the potential, provided British Telecom goes along with this, to fill up the numbers in between, 222, 333, etc, with a sliding scale of catastrophisation.

Let’s put in some examples to test the system.

You are Henry VIII, the most powerful king England ever had.

You have some marital issues, and in particular no male heir to the throne.

I’m thinking 333 would be about right.

Instead of which Henry over-reacts massively, dissolving the monasteries and the catholic church, divorcing his wife and executing some of his best pals.

There is no indication that the younger Henry was overly ‘buttoned up’, casting some doubt on the over-control theory. Although if he really had cerebral syphilis, that might have damaged some of his feedback loops.

Or try this one: Confronted with a pompous email from NHS management you write a reply you misguidedly think is witty, accidentally pressing the Reply to All button, so that every person in the whole NHS gets a copy.

555, agreed?

You eat a yogurt from your fridge mistaking the sell by date 2003 for 2013?

Not even 111, I don’t think. Yogurt never kills.

We are going to need an advisory panel of some kind as arbiters of how to interpret and assign a crisis to a number scale. This would be an efficient resource, especially if we can charge a premium rate for the crisis line. I hope the NHS is working on this.

Failing that I think Mitsubishi could run something up. For indecisive parking, press 111. For misspelt tattoos, press 222. For incorrect change, press 333…

What if the elevator seems awfully slow today? Press 444. Pressing using the fingers is sufficient. It is not necessary to use the axe.