What has neuroscience ever done for psychiatry?
19 July 2016
Psychiatry has a problem.
I love my profession of psychiatry, but one of the reasons I entered this most fascinating branch of medicine was because it seemed clear to me that it had problems and would see change in my lifetime. What then, is the problem with psychiatry? Well, to my mind it can be understood like this. If you go to a doctor with shortness of breath and a cough the doctor will investigate these symptoms for you. Typically the doctor will speak to you about your symptoms, listen to your chest and if you are bad enough, order an x-ray, blood test and blood cultures. In the end, a specific diagnosis will be reached. This diagnosis might, perhaps, for example, be of an infective pneumonia. On the basis of that diagnosis, a tailored treatment will be given to you, and you will, in all probability, get better.
Let us contrast this with the situation in psychiatry. If you go to a doctor with a symptom like depression, a doctor will also talk to you and take a detailed history of your condition. However, it is very unlikely that any specific tests that are informative can be conducted and at the end of the process the doctor will tell you that you have a diagnosis of depression which is, after all, the symptom that you came in with. You may be offered a treatment, either psychological therapy or drug treatment, but the doctor cannot be certain that it will treat your particular depression mainly because he or she doesn’t know the exact causes of the illness in you. And this is the key point. Psychiatry is the last branch of medicine to move from describing things to understanding their causes and until we understand the causes of these conditions we won’t be able to treat people better.
The good news, however, is that this change is happening now. We are beginning to understand much more about the causes of mental health problems and we can start to think about how we may treat them better. I believe that neuroscience has a major role to play in making this transition. However, before moving on to think about what neuroscience can do in the future, it is perhaps worth thinking about what neuroscience has already done for psychiatry.
What has neuroscience done for psychiatry?
Perhaps one of the most important things that attracted me into psychiatry is the fact that we do have some treatments for the major conditions that we see, such as depression or psychosis or anxiety. Many of these treatments were discovered by chance, sometimes in strange and mysterious ways, however neuroscience has enabled us to understand the ways that these different treatments work. This has, in turn, told us something about the possible causes of conditions such as depression and schizophrenia. For example, we know that most of the major antidepressant medications that we use work by affecting a chemical system in the brain involving neurotransmitter serotonin.
Similarly, drugs treating schizophrenia and psychotic symptoms tend to act on the dopaminergic system in the brain. Understanding the chemical systems on which these medications act has enabled us to design some better tolerated versions of the drugs and importantly to predict and monitor better side-effects. However, disappointingly, neuroscience has yet to identify many new treatments for the major conditions that we see in patients.
Neuroscience has also shown us, to my mind irrefutably, that psychiatric conditions have their basis in the brain. Whilst in most psychiatric disorders a pathology cannot be seen down a microscope, with the exception of conditions such as Alzheimer’s Disease, brain scanning has enabled us to see that there are subtle differences in the brains of those who suffer from conditions such as schizophrenia compared to those who don’t. Whilst this is often taken for granted now, when such advances were first made 40 or so years’ ago, they changed perceptions from thinking that schizophrenia was caused by bad parenting to realising that it was a real condition of the brain. Since that time, there have been huge advances in brain scanning but unfortunately they have yet to have major impact on our clinical practice.
Perhaps the other single biggest advance, if I had to select just one more, would be in the area of psychiatric genetics. We have long known that many psychiatric conditions have a tendency to run in families. However, despite decades of research it proved very difficult to identify specific genes involved in confirming this for conditions such as Alzheimer ’s disease or schizophrenia. However, recently, in a heartening example of scientists working together and collaborating around the globe, big studies have been put together which have had sufficient power, combined with new technology, to begin to reveal the genetic risk factors that contribute to the risk of these conditions. This is doubly important as genetics is a bounded way in which to gain some insight into the biological systems in which changes may lead to vulnerability for mental health problems.
What might neuroscience yet do for psychiatry?
Perhaps the greatest excitement is what neuroscience may yet bring to psychiatry. Technology has advanced hugely over recent years and studies are now possible that we never thought we would be able to do. Combined with our understanding of genetic risk and, of course, of the risk mediated through various environmental factors such as stress, we now have the tools to much better understand what happens in the brain, to the cause of symptoms of mental disorder. Whilst there are too many different advances in neuroscience for me to list them all, one perhaps will serve as an example.
A major difficulty when studying brain disorders such as schizophrenia, depression or Alzheimer’s disease has been that we don’t have access to brain tissue from living people with the condition. This contrasts with the situation of something like a skin cancer or a liver disorder where a biopsy can be taken. Through amazing advances in stem cell technology, however, we can now take simple samples of skin or hair from patients with a psychiatric condition and can grow these in a dish in a way that allows the cells to turn into neurons or brain cells.
This means that we can, for the first time, study the living brain cells from patients with psychiatric conditions. Whilst this technology has only recently become available, it already seems likely that as it is developed it will make a major contribution to our ability to understand these conditions. Combined with other areas of technological advance such as huge developments in our ability to scan the living brain in humans to understand the way the different brain regions interact in both health and disease, I have real optimism that we will see a new wave of both understanding and treatment for psychiatric conditions in the decades to come.
What can neuroscience do for training in psychiatry?
These exciting developments in neuroscience also offer a way to attract young scientifically interested people into psychiatry and related disciplines. In America, neuroscience is now one of the most popular areas for research among the brightest medical graduates and certainly here in Cardiff our own neuroscience PhD programmes are hugely popular and massively over-subscribed. This means that we can bring some of the brightest and best people into the field of neuroscience and some of them also into the field of psychiatry and mental health.
For what has been, in the past, seen as a ‘Cinderella’ speciality in medicine, these are exciting times indeed as we become, as Tom Insel, recently retired Director of NIMH in America has said, the ‘go to speciality’ for the best trainees. Whilst this transition has happened in America, we need to communicate urgently the excitement of neuroscience and the possibilities for understanding and treating brain disorders better to trainees in the UK as well so as to contribute to the re-energisation of psychiatric training in the UK.
One very positive development has been recent support from the Wellcome Trust and Gatsby Foundation to look at how neuroscience can be brought into training for medical and allied specialities.
What will the future of psychiatry look like?
In these exciting times it’s worth pausing for a moment to think what we might want future psychiatric practice to look like. I have no doubt that the cornerstone of our practice will remain interaction between doctors and other health service professionals and their patients based around a caring and empathic approach. It is this that makes psychiatry such a rewarding speciality and can generate such special relationships between the carers and their patients.
I also have no doubt that we will continue to need to consider people who suffer from mental health problems in a truly holistic way, thinking not only of their physical situation but also the social and environmental settings in which they find themselves. However, I hope that in the future we will also be able to use neuroscience methods to understand better the causes of vulnerability and risk of illness in individuals through brain scanning or molecular testing to enable us to us to much better target our existing treatments and develop new treatments, both psychological and pharmacological.
When our treatments are based on, and targeted against, the true causes of psychiatric symptoms we will have begun to solve the problems of psychiatry.
Professor Jeremy Hall receives funding from Wellcome Trust, MRC, EU, NRN, Astra Zeneca, Jane Hodge Foundation and The Waterloo Foundation