Often the terms “neurological disease” and “psychiatric disease” are used interchangeably , and there are even many experts who consider that there are no real differences between the two types of disorder.

In this article we will describe the differences and similarities between neurological and psychiatric diseases.

What are neurological diseases?

Neurology is the branch of medicine that deals with the study of the anatomy, functions and organic alterations of the nervous system . This discipline is largely based on the contributions of neuroscience, which is defined as the study of the nervous system as a whole and is nourished by methods such as cell analysis and neuroimaging.

When we talk about neurological diseases, we are referring in a general way to any type of disorder involving the nervous system, regardless of its causes or symptoms. It is therefore a very broad term that can be used for phenomena as different as insomnia and Korsakoff’s syndrome.

There are many different types of neurological diseases. These can be classified according to different criteria; if we are guided by the location of the alterations, one of the most common, we find neurological disorders that affect the brain, the spinal cord, the cranial nerves, the peripherals or the autonomic nervous system.

Some illustrative examples of disorders that are often categorized as neurological diseases are dementias and other neurodegenerative disorders, neuropathies, epilepsy, or behavioral disorders caused by brain injury, such as aphasia (affecting language) and apraxia (associated with movement planning).

The causes of neurological diseases are as varied as their manifestations . Among the most common are genetic alterations, nerve damage from external causes, infections, vascular disorders and lifestyle factors such as malnutrition or excessive consumption of certain compounds.

Psychiatric diseases or mental disorders

The concept “psychiatric illness” can be considered equivalent to that of “mental disorder” , which predominates in the field of psychology, with which psychiatry overlaps in a very significant (and often problematic) way. It is used to talk about disorders related to external behaviour or to what we know as “mind”.

Psychiatry is the specialty of medicine that deals with the diagnosis, prevention and treatment of mental disorders or illnesses. Unlike psychology, it specializes specifically in pathology; in this sense it is very close to clinical psychology, although psychiatrists can prescribe pharmacological treatments.

This discipline has been even more questioned than psychology in its conception and handling of mental problems. Critical perspectives on psychiatry deny the social labelling that derives from medical diagnoses, the rigidity of this type of procedure and the medicalisation of non-pathological interindividual differences.

Psychiatric illnesses can be due to both organic and environmental causes ; for example, traits such as neuroticism, which predispose to the development of anxiety disorders, are largely determined by genetic factors, although stress and other psychosocial variables (for example, substance abuse) are also fundamental.

Among the so-called mental disorders we can highlight disorders such as schizophrenia, attention deficit hyperactivity disorder or ADHD, anorexia and bulimia nervosa, post-traumatic stress disorder, dementia and bipolar disorder. As we see, some of them can also be categorized as neurological diseases.

Differences and similarities between these types of alteration

In general, psychiatry and neurology tend to be understood as complementary sciences. Thus, both would share an interest in many disorders, although each would deal specifically with some of them and place a different emphasis on the analysis of the manifestations of the disorders and their neurophysiological correlates.

However, there are those who consider that the syndromes we refer to as “psychiatric diseases” are simply neurological disorders whose anatomical and physiological features have not yet been fully identified. From this perspective, psychiatry would not be necessary but an example of the atavistic mind-body dualism.

David and Nicholson (2015) deny this idea and propose that the basic difference between neurology and psychiatry is that the latter focuses on behaviours and mental contents such as thoughts, perceptions and emotions, whereas neurology is concerned preferentially with the organic basis of disorders.

In the same line, Baker et al. (2002) warned that neurology should be cautious, although they stated that psychiatry would also benefit from the knowledge obtained by the neurosciences. According to the authors , mental health cannot be reduced to its neuroanatomical correlates ; each of these sciences would therefore have its own area of specialisation.

Bibliographic references:

  • Baker, M. G., Kale, R. & Menken, M. (2002). The wall between neurology and psychiatry: Advances in neuroscience indicate it’s time to tear it down. BMJ, 324(7352): 1468-9.
  • David, A. S. & Nicholson, T. (2015). Are neurological and psychiatric disorders different? British Journal of Psychiatry, 207(5): 373-4.