The subjective nature of psychiatric diagnosis

Medicalising natural and normal responses to life experiences is a dangerous game.

This may be the year that makes you mad. A new psychiatrist’s bible will be published in May and already it’s mired in controversy. Many see it as a pretext for scandalous over-diagnosis and drug-pushing.

The Diagnostic and Statistical Manual of Mental Disorders (DSM), published by the American Psychiatric Association, has enormous influence in shaping the way mental health research is carried out worldwide. It was first published in 1952 and the most recent edition appeared in 2000. It has taken over 12 years to agree on the contents of the fifth edition, DSM5.

One problem that people have with DSM5is that it will be oldfashioned: it will make no attempt to link behaviour or feelings to what is known about the physical states of the brain, in an era when neuroscience has made enormous advances in relating physiological issues with behavioural issues.

Take grief. Functional magnetic resonance imaging (fMRI) studies show that grieving people have higher activity in various regions of the brain, including the cerebellum and the posterior brainstem. We’ve all seen the results of this in ourselves or others: low mood, low motivation, loss of appetite.

Here’s the next problem: DSM5 will make it easier to medicalise natural human experience. After the new manual is published, psychiatrists will be able to diagnose people who have had two continuous weeks of this as suffering from depression, even if they are recently bereaved. What was normal behaviour last year will become a medical crisis.

The British Psychological Society and the American Psychological Association are among the mental health organisations that have raised concerns about such moves. Medicalising natural and normal responses to life experiences is a dangerous game. So far, more than 14,000 people have signed an open letter to the team drafting DSM5, expressing concern about some of the proposed changes “that have no basis in the scientific literature”. The letter argues that the changes “pose substantial risks to patients/clients, practitioners and the mental health professions in general”.

The pharma says

Particularly vulnerable, they argue, are children and the elderly. That’s because they are most at risk of having pharmaceutical solutions – many of which can have severe adverse side effects – foisted on them. And there’ll be more people and more conditions for which to prescribe drugs. DSM5 will lower the threshold of what it takes to get diagnosed with a disorder and will offer some new disorders, such as “disruptive mood dysregulation disorder”, a diagnosis for children who exhibit temper tantrums and get upset out of proportion to a situation.

Each positive diagnosis will be a candidate for drug treatment, which makes it particularly worrying that a study published in March last year identified strong ties between the pharmaceutical industry and those drafting DSM5.

The subjective nature of the psychiatric diagnosis has always been a problem. Freud knew this but his 1895 attempt at a “project for a scientific psychology” failed miserably. Back then, science had told us very little about the physiology and function of the brain. In 2013, it has revealed a lot more but there are still far too many gaps to claim that subjective analysis is redundant. Neuroscience is advancing fast; let’s hope we won’t need DSM6.

Michael Brooks’s “The Secret Anarchy of Science” is published by Profile Books (£8.99)

The new psychiatrist's bible is seen by many as a pretext for drug-pushing. Photograph: Getty Images

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 07 January 2013 issue of the New Statesman, 2013: the year the cuts finally bite

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Inside Big Ben: why the world’s most famous clock will soon lose its bong

Every now and then, even the most famous of clocks need a bit of care.

London is soon going to lose one of its most familiar sounds when the world-famous Big Ben falls silent for repairs. The “bonging” chimes that have marked the passing of time for Londoners since 1859 will fall silent for months beginning in 2017 as part of a three-year £29m conservation project.

Of course, “Big Ben” is the nickname of the Great Bell and the bell itself is not in bad shape – even though it does have a huge crack in it.

The bell weighs nearly 14 tonnes and it cracked in 1859 when it was first bonged with a hammer that was way too heavy.

The crack was never repaired. Instead the bell was rotated one eighth of a turn and a lighter (200kg) hammer was installed. The cracked bell has a characteristic sound which we have all grown to love.

Big Ben strikes. UK Parliament.

Instead, it is the Elizabeth Tower (1859) and the clock mechanism (1854), designed by Denison and Airy, that need attention.

Any building or machine needs regular maintenance – we paint our doors and windows when they need it and we repair or replace our cars quite routinely. It is convenient to choose a day when we’re out of the house to paint the doors, or when we don’t need the car to repair the brakes. But a clock just doesn’t stop – especially not a clock as iconic as the Great Clock at the Palace of Westminster.

Repairs to the tower are long overdue. There is corrosion damage to the cast iron roof and to the belfry structure which keeps the bells in place. There is water damage to the masonry and condensation problems will be addressed, too. There are plumbing and electrical works to be done for a lift to be installed in one of the ventilation shafts, toilet facilities and the fitting of low-energy lighting.

Marvel of engineering

The clock mechanism itself is remarkable. In its 162-year history it has only had one major breakdown. In 1976 the speed regulator for the chimes broke and the mechanism sped up to destruction. The resulting damage took months to repair.

The weights that drive the clock are, like the bells and hammers, unimaginably huge. The “drive train” that keeps the pendulum swinging and that turns the hands is driven by a weight of about 100kg. Two other weights that ring the bells are each over a tonne. If any of these weights falls out of control (as in the 1976 incident), they could do a lot of damage.

The pendulum suspension spring is especially critical because it holds up the huge pendulum bob which weighs 321kg. The swinging pendulum releases the “escapement” every two seconds which then turns the hands on the clock’s four faces. If you look very closely, you will see that the minute hand doesn’t move smoothly but it sits still most of the time, only moving on each tick by 1.5cm.

The pendulum swings back and forth 21,600 times a day. That’s nearly 8m times a year, bending the pendulum spring. Like any metal, it has the potential to suffer from fatigue. The pendulum needs to be lifted out of the clock so that the spring can be closely inspected.

The clock derives its remarkable accuracy in part from the temperature compensation which is built into the construction of the pendulum. This was yet another of John Harrison’s genius ideas (you probably know him from longitude fame). He came up with the solution of using metals of differing temperature expansion coefficient so that the pendulum doesn’t change in length as the temperature changes with the seasons.

In the Westminster clock, the pendulum shaft is made of concentric tubes of steel and zinc. A similar construction is described for the clock in Trinity College Cambridge and near perfect temperature compensation can be achieved. But zinc is a ductile metal and the tube deforms with time under the heavy load of the 321kg pendulum bob. This “creeping” will cause the temperature compensation to jam up and become less effective.

So stopping the clock will also be a good opportunity to dismantle the pendulum completely and to check that the zinc tube is sliding freely. This in itself is a few days' work.

What makes it tick

But the truly clever bit of this clock is the escapement. All clocks have one - it’s what makes the clock tick, quite literally. Denison developed his new gravity escapement especially for the Westminster clock. It decouples the driving force of the falling weight from the periodic force that maintains the motion of the pendulum. To this day, the best tower clocks in England use the gravity escapement leading to remarkable accuracy – better even than that of your quartz crystal wrist watch.

In Denison’s gravity escapement, the “tick” is the impact of the “legs” of the escapement colliding with hardened steel seats. Each collision causes microscopic damage which, accumulated over millions of collisions per year, causes wear and tear affecting the accuracy of the clock. It is impossible to inspect the escapement without stopping the clock. Part of the maintenance proposed during this stoppage is a thorough overhaul of the escapement and the other workings of the clock.

The Westminster clock is a remarkable icon for London and for England. For more than 150 years it has reminded us of each hour, tirelessly. That’s what I love about clocks – they seem to carry on without a fuss. But every now and then even the most famous of clocks need a bit of care. After this period of pampering, “Big Ben” ought to be set for another 100 or so years of trouble-free running.

The Conversation

Hugh Hunt is a Reader in Engineering Dynamics and Vibration at the University of Cambridge.

This article was originally published on The Conversation. Read the original article.