Observations on some diurnal rhythms in depressive illness

There are now a large number of potent physical treatments available for the depressed patient. Some of these carry an appreciable morbidity, and it is no longer appropriate that the physician should choose between them either at random or according to personal preference. The concept of the endogenous depressive process as a physiological state, aetiologically distinct from depressive changes which are dependent on psychological mechanisms, is widely accepted on the Continent, but is viewed with suspicion by many workers in America and in this country. Though it is often alleged that psychiatric diagnosis is a barren exercise, patients and the relatives of patients who suffer from manic-depressive disease can sometimes distin guish with clarity. between depressive attacks which are physiological in type and depressive spells which are reactive in origin and symptomatically different. These physiological depressions may arise, proceed, and remit without regard to psychological events. The concept of manic-depressive disease as a specific illness stems from the clinical observations of Falret (1854) and Baillarger (1854). In addition to manic-depressive disease, the term " endogenous depression " is now applied to single episodes of depression which are thought to be aetiologically distinct from manic-depressive disease. Further, many authors distinguish a subgroup of single depressions which are said to occur characteristically at the involutional period (involutional depression). These variants of endogenous depression are thought to be illnesses throughout which the patient retains the potentiality of complete remission. These illnesses occur typically in individuals with certain constitutional characteristics and are probably genetically dis tinct. Thus we are dealing with two sets of physiological and psychological phenomena : those which characterize the illnesses or attack states and differentiate patients from well people, and those which distinguish the constitutional make-up of indi viduals who are prone to these types of illness. The former phenomena should disappear with spontaneous remission or with successful treatment ; the latter are likely to persist unless the treatment produces a change in the constitution which may provide protection against future attacks. In any attempt, therefore, to seek diagnostic criteria it is important to distinguish between these two sets of physiological and psychological phenomena. One of the classic symptoms of endogenous depression is a diurnal variation in mood and symptomatology, which was, we believe, first described by Schneider (1920). In physio logical depression the depressive process is typically at its maximum in the early hours of the morning, and tends to improve during the day. In psychogenic or reactive depression it is said that each new day starts more hopefully than it finishes.