In the Japanese edition of DSM-5 published in 2014, the translation of major depressive disorder (MDD) was changed from "Dai-utsubyo-sei-shogai" to "Utsubyo" . However, in Japanese psychiatric clinics, a unique traditional concept of " Utsubyo " that is not related to the DSM was still alive until around 2000. I will refer to this as Nippon depressive disease (NDD), which is the source of the maxim, "Don't encourage people with depressive disease." Many people come to the outpatient clinic with complaints of depression, anxiety, physical discomfort, fatigue, and insomnia related to stress in daily life. Horwitz refers to these as the stress traditions. However, there is a group of people who appear to be in this stress tradition, but have their own medical condition, course, and response to treatment. This group shares characteristics with severe manic-depressive disease that requires admission to a psychiatric hospital. This clinical unit is worthy of differential diagnosis as NDD. The characteristics of NDD are as follows. Conscientious and tidy office workers and housewives are affected by changes in their living environment, such as moving to a new house or getting a promotion. The main symptoms are a feeling of gloom and worthlessness, loss of feelings of pleasure and sadness, retardation and inhibition of thoughts (i. e., inability to think clearly and make decisions, fatigue, exhaustion), and a vague feeling of ill health, as well as insomnia and loss of appetite. These are accompanied by diurnal fluctuations. These symptoms appear to be the stress-reactive depression that we all experience in our daily lives. However, although they appear to be empathic, in reality, emotional interactions are rejected. It is an uncanny experience beyond our imagination. It also takes the course of autonomy. It does not get better even when the person is relieved of stress. However, as a rule, it is mild and can be treated on an outpatient basis, as long as one pays attention to the risk of suicide. Patients get better with rest and antidepressants. Thus, the maxim that people with this condition should not be encouraged. Although it is named NDD, this type of disease itself has been reported overseas since the late 19th century. Later, in post-World War II West Germany, it became clear that there was a non-negligible number of cases of endogenous depression after the persistent stressful conditions of wartime destruction and postwar confusion. In Switzerland, Kielholz reported a number of exhaustive depressions with an endogenous course beginning with a stress reaction due to occupational exhaustion. He noted that antidepressants are effective for this condition and cautioned that encouragement of the patient is useless and often harmful. The psychopathological research results were first introduced to Japan in 1959. Thereafter, mild endogenous depression was released from its connection with the scars of war defeat and linked to the exhaustion of working businesspeople. Finally, it was termed "Utsubyo" without qualifiers, i. e., NDD. In the same year, antidepressants became available on the market. NDD was highlighted and treatment with antidepressants was promoted, and by 1975 it was established as "depression with melancholic personality type" . Small psychotherapy and the maxim "Don't encourage people with depressive disease" were included as treatments in textbooks from 1983 onward. However, when serotonin reuptake inhibitors (SSRIs) became available in 1999, the concept of "Utsubyo" was updated. SSRIs were indicated for MDD, not NDD. The stress tradition was incorporated into "Utsubyo" . In 2014, the Japanese term "Utsubyo" was changed to be equivalent to MDD. Here, the Japanese traditional concept of NDD was considered to be out-of-date. However, we should note that the diagnostic criteria for MDD are not expected to be valid as a biomedical model. It would be more fruitful for future biomedical or therapeutic research on depression-related conditions to use NDD as a starting point instead of MDD.
 Author's abstract