The biological approach to treating mental illness has been a lamentable failure. We must focus on a patient as a person.
Surveying the history of psychiatry, the medical historian Edward Shorter remarked: "If there is one central intellectual reality at the end of the 20th century, it is that the biological approach to psychiatry – treating mental illness as a genetically influenced disorder of the brain chemistry – has been a smashing success."
Far from being a success, there is compelling evidence that the biological approach has been a lamentable failure. Whereas last century saw dramatic improvements in the survival rates of patients suffering from heart diseases and cancer, so far as we can tell, outcomes for patients suffering from the severest forms of psychiatric disorder – the psychoses (disorders in which the patient experiences hallucinations or delusions, usually resulting in a diagnosis of schizophrenia or bipolar disorder) – have hardly changed since the Victorian period. Poor countries without well-resourced psychiatric services seem to do at least as well as the developed world. Therefore, although the perception is often different, there is little evidence that modern psychiatric services have had a global, positive impact on mental health.
At the beginning of the 21st century a new picture of severe mental illness is emerging, which shows that the genetically determined brain disease paradigm is not only ineffective but scientifically flawed. First, it seems that diagnoses such as schizophrenia and bipolar disorder do not identify discrete conditions analogous to, say, appendicitis or tuberculosis. Patients with a mixture of bipolar and schizophrenia symptoms are at least as common as patients who fit one or other diagnosis. The concept of schizophrenia is so broad that two patients can share the diagnosis while having no symptoms in common.
In the case of both types of symptoms, there appear to be many people whose experiences place them on the borderline between health and illness, so that we can think of a spectrum running from ordinariness, through eccentricity and creative thinking, to full-blown psychiatric disorder. Research has also shown that psychiatric diagnoses are poor predictors of response to treatment, giving little indication of which patients will respond to which drugs. They are therefore hardly more meaningful than star signs – another diagnostic system that is supposed to tell us something about ourselves and what will happen in the future, and which is widely embraced despite no evidence of its usefulness.
When new methods of molecular genetics have been used to study psychiatric patients, no genes of major effect have been found. The latest evidence suggests that many genes – possibly thousands – each make a tiny contribution to vulnerability to psychiatric disorder, and that these effects are highly non-specific (the same genes are implicated in patients with different diagnoses).
Some findings that were announced with enormous fanfare have not been replicated in subsequent studies. Much, for instance, has been made of the discovery of a variant of the 5-HTTLPR gene, which appears to make people liable to depression if they are exposed to unpleasant life events. A recently published analysis of the data available on this gene found no evidence that it directly causes depression, or that it makes people vulnerable to depression. However, it was found that negative life events had a direct impact on mood: as our mothers could have told us, bad things tend to make us miserable.
This last observation is consistent with other evidence that life experiences shape even the most severe forms of mental illness. Migrants have at least a four times greater risk of psychosis than other groups, and this effect is most pronounced if they live in areas in which they are in a minority. Early separation from parents has also been shown to increase the risk of psychosis, as have growing up in an urban environment and chronic bullying.
Many studies have also reported an association between trauma in early life and psychosis. These effects are large: one recent study estimated that individuals who had been sexually abused in childhood were 12 times more likely than others to suffer from serious mental illness, and another calculated that the population-attributable risk of a diagnosis of schizophrenia associated with an inner-city childhood was 15% (that is, there would be 15% fewer cases if we all grew up in the countryside). The risk associated with having a parent with the diagnosis is 7% (ie, there would be 7% fewer cases if patients stopped having children).
These effects are understandable in the light of psychological research. For example, early trauma seems to disrupt the process by which we distinguish between our own thoughts and our perceptions, leading to a specific risk of hallucinations. Disruption of early relationships with caregivers, coupled with victimisation, create a tendency to mistrust others and to anticipate threats, leading to paranoid delusions.
The cruel and ineffective treatments that characterised psychiatry in the mid-20th century – for instance, prefrontal leucotomy and insulin coma therapy – would not have been accepted had psychiatrists not been in thrall to the idea that mental illnesses are genetically determined brain diseases. Today, although mental health professionals are usually much more compassionate than in those dark times, psychiatric services continue to see their primary objective as ensuring that patients take their medication.
Legislation has been introduced allowing doctors to coerce patients to take their drugs with threats of a return to hospital if they do not comply. Patients often find that their own understandings of their troubles are ignored. A study of psychiatrists in London found that, when patients asked questions about the meaning of their experiences, the doctors typically changed the subject.
Meanwhile, research on the biology of severe mental illness continues to be prioritised over social and psychological research. Biological investigations into psychosis currently outnumber those on environmental factors by at least five to one, and are much more generously funded by the UK's Medical Research Council. To date, about 30 trials of cognitive therapy for psychosis have been completed; by comparison, in the period 2001-3, nearly 400 drug trials were published in the five leading American psychiatric journals. There is therefore an urgent need to develop a less drug-based, more person-centred approach to understanding and treating mental illness, which builds on the recent scientific findings and which takes the experiences of patients seriously.