Time to end the distinction between mental and neurological illnesses

We are witnessing a revolution in the clinical science of the mind, as the techniques of basic neuroscience are successfully applied in mental health. It has become clear that disorders of the mind are rooted in dysfunction of the brain, while neurological disorders interact strongly with psychological and social factors and often cause psychological symptoms. Yet the dominant classifications of mental disorder—the International Classification of Diseases (ICD) and the Diagnostic and Statistical Manual (DSM)1 2—continue to draw a sharp distinction between disorders of the mind, the province of psychiatry, and disorders of the brain, the province of neurology. As these classifications are currently under revision, it is timely to consider a radical rethinking.3 4 The current line of demarcation between disorders of mind and of brain is counterproductive for clinicians and patients on both sides of the line. We propose, therefore, that psychiatric disorders should be reclassified as disorders of the (central) nervous system. This will update our classificatory system in the light of contemporary neuroscience and foster the integration of psychiatry into the mainstream of medicine, where it belongs.

Biological research into mental disorders has been transformed by advances in structural and functional brain imaging, neuropharmacology, and genetics.5 Meta-analyses have shown that structural brain abnormalities are present in schizophrenia,6 7 bipolar affective disorder,7 8 recurrent depressive disorder,9 post-traumatic stress disorder,10 and obsessive compulsive disorder.11 Functional brain imaging has shown that both normal and abnormal emotions have neural representations.12 Meta-analyses show altered …