The appointment of Luciana Berger as shadow minister for mental health in Jeremy Corbyn’s shadow cabinet, the first politician in the UK to hold such a portfolio, is a sign of how far mental health has come as a subject fit for public discussion and action rather than for purely private misery. What has changed in recent years is not so much public awareness of the scale and the costs of mental illness, whether in terms of direct suffering or of disruption to active life and work. There has indeed been some advance in public understanding, so that fewer people would now be surprised to learn that, as Richard Layard and David Clark put it in their book Thrive, “depression and anxiety account for more of the misery in Western societies than physical illness does. And they account for very much more misery than is due to poverty or unemployment”.
More important even than this is the growing awareness that mental illness can be treated, not always and everywhere but still more reliably, humanely and economically than could ever have been imagined a generation ago. Surprisingly perhaps, the treatments that have been found to work include not just pills, which continue to be the treatment of choice for psychotic conditions and bipolar disorder. In addition, unipolar depression and anxiety disorders have been found to respond systematically to some forms of psychotherapy, most of which were considered until fairly recently so impossible to evaluate objectively that only in comic fiction could they have been imagined being available on the National Health.
In particular, Cognitive Behavioural Therapy (CBT), which consists of short sequences of focused sessions aimed at treating specific problems through management of negative thought processes and behaviours, has now been subjected to randomized controlled trials that have shown it to be both clinically and economically effective. To quote Layard and Clark, “Psychological therapies taking less than sixteen sessions produce 50 per cent recovery rates which are often permanent; and, when they are not, they greatly reduce the risk of relapse”. The cost of such therapies is small compared to many courses of treatment for physical illness (comparable to six months of anti-diabetes treatment, for instance). They can also produce savings on physical treatment for those patients whose physical and mental illnesses are interconnected.
Many individuals and institutions have been responsible for this change, including in particular the National Institute for Health and Care Excellence (NICE), which has been reviewing systematic evaluations of various forms of psychotherapy. Not all the kinds of psychotherapeutic intervention that common sense would suggest do in fact work, and some are positively counter-productive. It was once widely believed that immediate debriefing of road accident victims would help them to come to terms with their trauma and reduce the risk of subsequent post-traumatic stress disorder. Careful controlled trials have shown that post-accident debriefing actually reduces natural recovery rates from trauma. Common sense suggests that facing up to your trauma is the thing to do; but common sense appears to be wrong.
Similarly, even when they are effective on average, some forms of intervention work better than others: CBT appears to work better than interpersonal psychotherapy for social phobia, for example. We don’t really know why, which is frustrating. Clinical trials of psychotherapy more rarely illuminate the mechanisms by which interventions function than do trials of medication. But even in the domain of psychopharmacology such illumination is usually partial. It is one thing to know that a particular pill inhibits serotonin re-uptake, and quite another to have any idea why this is associated with reductions in depressive symptoms in at least some patients. This is especially so since in other patients apparently opposite mechanisms can also be therapeutically effective.
Since 2008, thanks both to the availability of clinical trials of CBT and to a major political initiative undertaken by the then Health Minister Alan Johnson, a programme called “Improving Access to Psychological Therapies” (IAPT) has been under way in England. As of 2013 IAPT was treating nearly 400,000 people a year with short courses of therapy, mainly but not only CBT. Reported recovery rates of those treated, at 46 per cent, are less good than ought to be possible, and are highly variable across the country. But they appear to be correlated with the experience and training levels of the therapists, which suggests they should improve as the programme becomes more established; more than 5,000 new therapists were trained in its first five years.
On the face of it this is an extremely impressive achievement, and one that begins to compensate for the long-standing neglect of mental health as a public policy priority. It is also a success for evidence-based medicine, since without the evidence accumulated by NICE there would never have been the professional and political consensus required to give impetus to the programme. Layard and Clark (who were both integral to its design and implementation) have written a clear and informative book that has an undisguised agenda but is open about its limitations – faithful to the spirit of evidence-based medicine, in fact. However, they are over-inclined to take randomized controlled trials at face value, and say nothing about the accumulating evidence that these may overstate the case in favour of the evaluated treatments.
We are starting to learn more about the extent to which a scientific consensus may be affected by publication bias – the preference of scientific journals for publishing the results of studies with positive findings and ignoring those with negative ones. A paper in Science last August by the Open Science Collaboration reported the results of replication attempts for a hundred studies in social psychology. It was able to report significant findings for only 36 per cent of them, with average reported effect sizes being around half of those reported in the original study. A paper by Ellen Driessen et al in PLOS One in September looked more specifically at studies of psychotherapy treatments and reported that including the results of unpublished studies reduced estimated treatment effects by around one-quarter. This may underestimate overall publication bias since it excludes possible biases within published studies. None of this, of course, is an argument against randomized controlled trials – it is an argument for more of them and for better ones. But it also suggests a brake on the enthusiasm with which we draw conclusions from studies that have not been independently replicated.
A more subtle reason for caution lies in the evaluation of recovery rates. Often a reported recovery from depression is just that. But it may also be reported by a patient in order to please a therapist, or by a therapist in order to please a supervisor, or by an administrator in order to please a manager. None of these individuals need be lying, merely seeing what they very much want to see along a dimension where there are no clear boundaries. They may also be influenced by norms about what counts as ordinary unhappiness and what is a pathology, and such norms can change.
These considerations are an important limitation on our ability not just to evaluate psychotherapy, but more generally to draw conclusions about well-being and happiness from self reports. For instance, a 2009 study by Betsey Stevenson and Justin Wolfers showed that women’s self-reported happiness in America had declined over thirty-five years from the early 1960s. Was this a sign that economic and social change had really lowered women’s happiness (as the resulting heated debate mostly took for granted), or rather that norms about reporting had changed, and women could now own up more easily to dissatisfaction with their lives? It’s not impossible to investigate such questions, but the studies that do so are sparse relative to those that simply take reported outcomes at face value. As a general rule, what William Davis calls “the happiness industry” (of which Richard Layard has been a high-profile advocate, for instance in his book Happiness: Lessons from a new science, 2005) does not concern itself with such niceties of interpretation but assumes that what people say about their psychological well-being is more or less uncomplicatedly the truth.
Even if accurately reported, recovery rates are not everything. There is a long and (mostly) honourable tradition in psychotherapy that sees its purpose as self-understanding rather than cure. In the view of this tradition, the short, targeted interventions characteristic of CBT barely scratch the surface of our deepest problems, and provide relief (when they do) without corresponding insight. Layard and Clark do not deny this tradition, but they are not very interested in it either, and they certainly don’t think it is of any relevance to public policy. So their defence of CBT should be seen as pragmatic. Public funding of treatment cannot reasonably be based on anything else than evidence, and evidence has to rely on randomized evaluations and reported recovery rates. Those who want insight rather than recovery cannot reasonably expect the taxpayer to indulge them. And nobody, least of all Layard and Clark, claims that CBT solves all or even most mental health problems. But on the evidence we have so far it looks capable of alleviating a more substantial proportion of them than any single other treatment that has yet been tried on a large scale.
Richard Layard and David Clark do not spoil a good case by over-pleading. The same cannot, unfortunately, be said of William Davis, whose book The Happiness Industry begins promisingly, with an enjoyable historical survey of attempts by psychologists from Jeremy Bentham onwards to understand the roots of human well-being. He writes subtly and amusingly about the many attempts that have been made to reduce the complexity of the human mind to simplistic causal processes, and to consider that all that is worthwhile in human endeavour can be encapsulated in a single dimension – whether that be Bentham’s utility, or the electrical traces recorded on Francis Edgeworth’s hedonimeter, or changes in the concentration of neuro-transmitters such as dopamine and serotonin. And he provides many good reasons for thinking that direct observation of brains or behaviour can never fully substitute, either scientifically or politically, for giving subjects a voice in the expression of their own well-being.
This article had been publisehd in the Times Literary Supplement
