The Inflamed Mind - Book review by Terry Smith

The Inflamed Mind' was an eagerly anticipated read having been recommended by some prominent influencers in the persistent pain world. The book is the work of Professor Edward Bullmore, who comes with an impressive CV. Since 1999, Bullmore has been the Professor of Psychiatry at the University of Cambridge and is the Director of the Wolfson Brain Imaging Centre in the Department of Clinical Neuroscience. He is also an honorary Consultant Psychiatrist and Director of Research and Development for Cambridgeshire and Peterborough NHS Foundation Trust.

Essentially, Bullmore's 'The Inflamed Mind' lays the foundation for the argument that some depression is caused by bodily inflammation that can penetrate the blood brain barrier to inflame brain cells and networks and thus cause the mood and behavioural changes seen in depression. This bodily inflammation can be caused by social and physical stress as well as obesity and inflammatory conditions such as rheumatoid arthritis.

'The Inflamed Mind' avoids excessive medical jargon and the neuro-immunology explanations are superficial enough to explain his theories without losing the reader (more accurately without losing this reader). To this end, the book is easy to read and I think will be accessible to those outside of the medical and academic communities.

Bullmore begins his argument by introducing the underlying theory of the book incorporating the workings of the immune system. He states that this relatively simple and in-plain-view cause of depression may have been missed over the years due to the 350 year old views of Descartes that still influence medicine today. I supported this repeated theme of the book with silent nods as Bullmore acknowledges the 'Cartesian divide' that still exists within medicine that attempts to understand pathology by splitting the brain and body into separate units. He urges the medical community and reader to do away with this unhelpful compartmentalising of the human. I think many in the world of persistent pain will applaud the push to see the person as a whole integrated organism rather than the unhelpful psycho-somatic split that still persists.

When attempting to answer the question of why inflammation might cause depression I was particularly pleased to see a section on Darwin. I find it difficult to understand any human phenotype, whether physical or behavioural, without seeing it through the lens of evolution. Bullmore admits 'ultimately, the answer must always be Darwin’. That said, I found his evolutionary explanations of depression unconvincing and heavily biased towards the immune system, I suspect as a way to add credence to the underlying theory of the book. Bullmore postulates that depression may have been selected for, to protect ill ancestors from social obligations and competition when they need to rest or as a form of quarantine for infected individuals so as to prevent infection wiping out an entire tribe. Essentially socially isolating oneself for the greater good of the community. I wonder what Dawkins’ Selfish gene theory would make of this group selection explanation? Personally,  I prefer John Cacioppo’s work on loneliness and Randolph Nesse's evolutionary theories of depression that suggest depression may have been selected for as protection from, or deterrent to any decline in social status or interpersonal loss (death of a loved one, decline in skills with ageing). These theories make more adaptive sense to me in social animals such as humans.

Bullmore’s discussion on treatment for this potential sub group of patients with inflamed depression is heavily biased towards medication citing possible anti-inflammatory drugs as the future treatment. I couldn't help letting out a little sigh at this point. Bullmore has previously worked for GlaxoSmithKline and is currently leading an academic-industrial consortium for the development of new anti-inflammatory drugs for depression. With this knowledge in mind I couldn't help wondering if I was really reading a 'big-pharma' propaganda script. There were a few throw away lines on meditation, mindfulness and talking therapies but not a substantial amount despite him acknowledging that social stress as well as physical stress can cause bodily inflammation, something I often find difficult to put across to my medical colleagues despite the many articles in publication pointing this out.

Bullmore does offer up some evidence to support his claims but after an initial excitement the book leaves me underwhelmed. Some interesting theories that if proved correct may help a sub group of depressed people. It's certainly not going to be a panacea for depression and the big itch I currently have is 'if it's proved correct'. Bullmore does provide some correlation data to support the underlying theory of the book and I think there is enough evidence to warrant further research but currently the evidence is severely lacking to fully support his claims. Bullmore states 'it is now clear beyond reasonable doubt that they (inflammation and depression) are linked, and they can be causally linked' which seems a bombastic claim based on the evidence provided in this book. This, of course, doesn't mean that he's wrong, just a long way off from proving the theory. I think the recent interest in the understanding of the immune system and its link to a variety of conditions, not least persistent pain, is a positive step in the right direction. For now I’ll put this book to one side whilst I keep a sceptical eye on whether the research catches up with the claims.