[Chaotic use of depression-related medical terms: how should it be settled?].

Along with the marked increase of depressive patients, psychiatric terms related to depression have come to be exposed to many lay people in recent years. As a result, various psychiatric terms formerly interpreted and used correctly by psychiatrists have been simplified too much into only a few words such as "utsu", which are often used in an inappropriate way. The new word "utsu" was originally a fragment of words such as "utsu-shoujou" (= depressive symptom),"utsu-joutai" (= depressive state), or "utsu-byou" (= depressive illness). Thus, the lack of postfixes indicating symptom, state, or illness appears to have caused the ambiguity of "utsu". The ambiguity (polysemy) of the word "utsu" is partly derived from that of the English word "depression", which indicates either depressive symptoms or depressive illness, or even within-normal depressed emotion, depending on the context. The use of "utsu-byou" (= depressive illness) is also confusing in terms of which disorders (illnesses) to include, because of the interchangeable use of "utsu" and "utsu-byou". The author contends that the chaotic use of the depression-related terms should be organized along the following "vertical" and "horizontal" axes: the vertical being the symptom-state-illness dimension, and the horizontal being the range of disorders. Specifically, the use of "utsu-byou" should be confined only to depressive illnesses which include definite ICD-10 and DSM-IV disorders, and another term, "yoku-utsu", is recommended for "depressive symptom" and "depressive state" with the postfix of "-shoujou" and "-joutai", respectively. The use of "utsu" in an ambigous way should be avoided. The author also contends that the traditional brief Japanese term "utsu-byou" maintains validity as a term indicating a certain clinical unit in a clinical situation, even though the Japanese translated disorder names of DSM-IV and ICD-10 may also be in use in a formal situation. There are three conditions for the authors' latter contention. First, the conceptual definition of the illness including its longitudinal course should be kept in mind. Secondly, symptom evaluation should be conducted through specialized techniques by psychiatrists. Thirdly, cautious observation looking for new findings should be maintained for a long time in parallel with treatment.