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Time to end the distinction between mental and neurological illnesses

BMJ 2012; 344 doi: https://doi.org/10.1136/bmj.e3454 (Published 24 May 2012) Cite this as: BMJ 2012;344:e3454

Rapid Response:

Re: Time to end the distinction between mental and neurological illnesses

The authors of this article suggest that mental and neurological disorders should be grouped together into disorders of the nervous system. This contention seems extraordinary given that the authors have previously strongly argued that many neurological disorders could be explained in social and psychological terms, under the banner of biopsychosocial medicine (1).

One such disorder is that of chronic fatigue syndrome, previously known as myalgic encephalomyelitis. In the case of ME/CFS, psychiatrists such as White have long argued that ME/CFS is a social and psychological condition rather than a neurological condition. ME has been formally classified as a neurological disorder by the World Health Organisation since 1969. ME as a neuro-immune-muscle disease had been established by Ramsay in the 1950s. In the 1970s UK psychiatrists McEvedy and Beard reclassified the disease as a psychiatric disorder of mass hysteria (2). In the 1980s psychiatrists such as Wessely looked again at this condition and asserted affective disorder, and then somatisation disorder, as explanatory models for the disease (3). In 1991 UK psychiatrists redefined ME as chronic fatigue syndrome, under the Oxford Criteria, a somatoform psychiatric mental health disorder (4). It is doubtful that White et al are advocating a return to Ramsay’s model or reasserting the WHO’s definition of ME; instead this article may well be viewed as an attempt to widen the scope of psychiatry into the neuroscience domain.

Historically, psychiatry as a medical discipline has been prone to medical misdiagnoses, whereby neurological conditions have often been wrongly classified as mental health disorders: epilepsy as a form of hysteria, multiple sclerosis as a form of hysteria, and ME as a form of hysteria. We now know via advancements in neuroscience that epilepsy is a brain disorder, and MS is a serious neurological disease. Such examples warrant note as they highlight the risks of homogenising psychiatric and neurological disorders into a unitary category. Neuroscience is a rapidly developing medical discipline. White et al are right to point out that new imaging and investigative techniques may well lead us to discover the underlying pathology for many mental health disorders, however this may well shine a light on the deficiencies of modern psychiatry, rather than evoke a need to integrate mental health and neurology. In the case of ME/CFS, White and other psychiatrists have called into question the possibility that the disorder may be caused by an underlying neurological disease. Specifically, White and colleagues have questioned the existence of neurological inflammation or infection, yet in the above article White et al cite basal ganglia disorders as cause of cognitive dysfunction. Cognitive dysfunction is a prominent symptom of ME/CFS (5). It is widely speculated that ME/CFS may well be linked to some undiscovered pathogen that causes insult to the brain/nervous system with resulting brain and/or basal ganglia inflammation.

Since the 1970s, some 40 years, psychiatrists have dominated ME/CFS research. White has been one of the prominent psychosomatic researchers of ME/CFS, yet the underlying cause of ME/CFS remains unknown. Only very recently, following the XMRV controversy have neuroscientists, immunologists and others, started to look again at this once defined mental health disorder. Fresh studies have revealed some of the underlying biological abnormalities (6,7). It is likely that advances in neuroscience will reveal the pathogenesis and pathophysiology of ME/CFS, rather than a continuance of psychiatric approaches, which have up until now resisted a neurological model of the disorder.

Given the historical perspective, that many neurological conditions are often misdiagnosed as mental health disorders, it is perhaps a wiser course of action to continue to demarcate the boundaries between psychological disorders and neurological disorders; if for no other reason than to minimise the potential for bias and illness misdiagnosis.

References:
1. White, P. (2005) Biopsychosocial Medicine: An Integrated Approach to Understanding Illness, Oxford University Press.
2. McEvedy, C.P. and Beard, A.W. (1970a) Royal Free epidemic of 1955: a reconsideration, BMJ, 1, 7-11.
3. Hotopf, M., Wessely, S., and Sharpe, M. (1998) Chronic Fatigue and Its Syndromes, Oxford University Press: Oxford.
4. Sharpe, M.C., Archard, L.C., Banatvala JE, et al. (1991) A report - chronic fatigue syndrome: guidelines for research, J R Soc Med, 84, 2: 118-121.
5. Carruthers, B., van de Sande, M., de Meirleir, K., et al. (2011) Myalgic Encephalomyelitis: International Consensus Criteria, J Intern Med, 270, 1365-2796.
6. Kennedy G, Khan F, Hill A, Christine C, Belch JJF. (2010) Biochemical and vascular aspects of pediatric chronic fatigue syndrome, Arch Pediatr Adolesc Med, 164, 9: 817-823.
7. Maes, M., Twisk, F.N. (2010) Chronic fatigue syndrome: Harvey and Wessely's (bio)psychosocial model versus a bio(psychosocial) model based on inflammatory and oxidative and nitrosative stress pathways, BMC Medicine, 8: 35.

Competing interests: No competing interests

27 May 2012
Keith Geraghty
Public Health Research
Manchester University
School of Community Based Medicine, University of Manchester, Manchester, M13, 9PL