Psychosomatic Medicine, Psychiatry, Neurology Differences

Today, we live in a “stress society”. Chronic diseases and stress-related diseases are increasing along with the related disorders of the mind and body. The causes are not only organic (biological) factors such as viruses and tumors, but also “psychological and social factors,” which are becoming increasingly complex.

On the other hand, medical care has become increasingly specialized and segmented, and the reality is that “it is difficult to reach the appropriate department”. In medicine, which deals with increasingly complex diseases, it may be helpful to know the difference among Psychsomatic medicine, Psychiatry, and Neurology.

Psychosomatic Medicine

Psychosomatic Medicine is mainly focuses on “psychosomatic disorders”. (The terms ‘psychosomatic disorders’ in the broadest sense and ‘psychosomatic diseases’ or ‘psychosomatic illness’ in the sense of specific illnesses are used.)
Psychosomatic disorders are physical diseases that involve pathologies of psychosomatic correlations (mind-body correlations).

While “mental illnesses” are diseases with psychopathology, physical illnesses are diseases of the body, such as cardiovascular diseases like heart failure, respiratory diseases like asthma, and digestive diseases like stomach ulcers. In all of these areas, it is estimated that about 1/3 of them involve significant psychosocial factors.
Simply put, physical symptoms related to stress and other psychosocial factors. If such a condition is suspected, psychosomatic medicine is appropriate.


Psychiatry specializes in the above “mental illnesses” and is a specialty that deals with symptoms of the mind (psychiatric symptoms) and mental illnesses. Mental symptoms include anxiety, depression, insomnia, irritability, hallucinations, auditory hallucinations, and delusions. While physical illnesses have a physical pathology, many mental illnesses have a brain pathology, but there are cases in which there is no clear brain abnormality or in which a physical abnormality is the basis of the disease.
As a rule, psychiatry is appropriate for mental symptoms, even if they are minor. Psychosomatic medicine is not the same as “mini-psychiatry” or “mild psychiatry”.


Neurology deals with diseases of the cranial nervous system. It is “internal medicine that looks at diseases of the brain, spinal cord, nerves, and muscles,” and is a department that deals with neurological diseases such as cerebrovascular disorders, Parkinson’s disease, and neuropathies. In this case, “nerves” are not “thick” or “nervous”, but actual “nerves” with substance that actually connect to muscles and other tissues and transmit signals. Neurological symptoms are different from the above-mentioned symptoms of the mind (psychiatric symptoms), and are symptoms due to motor disorders such as trembling hands, inability to move (paralysis), inability to walk or talk, and sensory disorders such as inability to see or hear.

コラム 心療内科・精神科・神経内科の違いアイキャッチ

How to distinguish

There seems to be some confusion between psychosomatic medicine and psychiatry
Roughly speaking, if physical symptoms are the main symptoms, then internal medicine, if neurological symptoms are the main symptoms, then neurology. If these physical symptoms are related to psychosocial factors such as stress, or symptoms that span the mind and body, then psychosomatic medicine. If the symptoms are mainly mental symptoms, psychiatry is appropriate.

For example, if the main symptom is a stomachache, then internal medicine (gastroenterology) is the first choice. However, if an examination reveals no medical abnormalities and the problem is caused by stress at work, or if the physical symptoms are accompanied by mental symptoms such as depression, then psychosomatic medicine is the appropriate medical specialty. On the other hand, if depression or anxiety is the main concern, then psychiatry is the right choice.

Guidelines for which department to consult

  • Mainly physical symptoms, but no abnormality is found after examination, or the course of the disease seems to be related to stress, etc. ⇒ Psychosomatic Medicine
  • The main symptoms are mental symptoms such as insomnia, anxiety, irritability, depression, and hallucinations. ⇒ Psychiatry
  • Abnormalities of nerves are suspected, such as strange body movements, shaking, leaning, lack of strength, etc. ⇒ Neurology
  • Physical and mental symptoms are equally present, and it is difficult to distinguish which is the main symptom. ⇒ Visit a psychosomatic medicine or internal medicine to rule out organic diseases.
  • I have recently experienced a strong feeling of stress and my physical condition has deteriorated since then, but this was not the case before. ⇒ Psychosomatic Medicine

There are many other cases and it depends on the circumstances of the facility. There are many times when you may be unsure of your choice. In such cases, we recommend that you call the medical institution first before making a wasted trip.

Note: The above guidelines are mainly based on the actual medical situation in Japan. The actual situation may differ from country to country or region to region.

Basic Concepts of Psychosomatic Medicine

The more essential aspect of psychosomatic medicine is how to view and approach disease.

“Psychosomatic medicine is a medicine that takes into consideration the relationship between the mind and body and the environment surrounding the person, without separating each element. It is Medical science that tries to look at the relationship between mind and body (mind-body correlation) in an integrated manner”.

The separate viewpoint of the elements is a very important view emphasized in Western medicine and is the basis for the development of today’s medicine. However, as mentioned at the beginning of this article, the number of chronic and complicated diseases has increased, and it is no longer possible to treat them successfully using only this viewpoint, and we are beginning to see its limitations. In contrast to Western medicine, Oriental medicine emphasizes “a holistic and integrated viewpoint” rather than separating elements. Japanese psychosomatic medicine is based on the Oriental viewpoint, but fuses the Eastern and Western views and approaches by “dividing the elements and then looking at their relationship as a whole”.

This approach can be applied not only to internal medicine but also to other departments such as otolaryngology and orthopedics. In such cases, the department would be called “psychosomatic otolaryngology” or “psychosomatic orthopedics,” but currently only “psychosomatic medicine” is recognized as a medical specialty by the Japanese insurance system. The Department of Psychosomatic Medicine also treats psychosomatic disorders in other departments in cooperation with specialized departments.

(Kanbara K, Psychosomatic Labo/ LABs Psychosomatic Medicine,, July 2021)

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