For more than 2000 years in the West, neurology and psychiatry were considered part of one unified branch of medicine, often called neuropsychiatry. Charcot, Freud, Jackson, Bleuler, among many others, thought in terms of a unified study of the brain and mind, regardless of specific clinical and research interests. However, during the 20th century, a schism emerged as each of these fields went their own way. Neurologists focused on brain disorders with cognitive and behavioral abnormalities that were also accompanied by somatic signs - stroke, multiple sclerosis, Parkinson's, and so on - while psychiatrists focused on mood and thought disorders that were not accompanied by physical signs found on neurological examination of the motor and sensory systems - schizophrenia, depression, anxiety disorders, and so on.
Most people affected by mental and neurological disorders do not have access to a wide range of evidence-based interventions that can prevent and treat these disorders, resulting in a huge treatment gap. This problem is not just limited to mental and neurological disorders as cost-effective interventions in other health sectors are inadequately available and underutilized. De Savigny and Adams have mentioned, "evidence-based interventions often fail to achieve their goals, not because of inherent deficiencies in the intervention itself, but because of the unpredictable behavior of the system around it".
Because of the enormous increase in neurobiological knowledge in recent years, and the growing number of disorders (including those mentioned above) that were once thought to be psychopathological but are now known to be neuropathological, some neurologists may cling to the view that their specialty has now emerged alone as the queen of medical science. Neurologists and psychiatrists must have a fairly broad perspective, as the domains of intentional behavior and intentionality (final causation) are brain/mind functions that are no less important than sensory perception and movement. Clearly, the education of future generations of neurologists and psychiatrists should be grounded in neuroscience, but should also be focused on those dimensions of professional activity that essentially define the work of medical doctors from the neck to the head.