To reflect is to disturb one's thoughts.

John William Waterhouse, Gather ye rosebuds while ye may, 1909.

Pathological mood is expressed as pervasive and unremitting apprehension and gloom that colors all cognitive processes, resulting in a loss of interest, decreased concentration, poor memory, slowed thinking, feelings of failure and low self-worth, and thoughts of suicide. Regardless of antecedent events, whether a personal loss or a general medical illness, a persistent and unrelieved feeling of gloom is essential to the diagnosis.

Psychomotor disturbance, either as retardation or agitation, is the second characteristic. Retardation varies from a reluctance and hesitation to participate in daily activities, to prolonged inactivity that is so severe as to be labeled a stupor simulating death.

Agitation appears as restlessness, hand-wringing, and inability to remain still. It may be expressed as pacing and continuous movement progressing to purposeless activity so severe that it has been described as furor or frenzy. Vegetative functions are severely aVected.

Sleep is disrupted, appetite and weight lost, sex no longer arouses interest, and the response to stress and chronobiologic functioning are disturbed. Patients describe these changes as beyond their understanding or control, or the signs of illness are obvious in a loss of weight, unkempt appearance, body odor, and haggard look. Neuroendocrine dysfunctions are identified in laboratory studies.

Psychosis is recognized when the disorder is severe and occurs in over 30% of melancholic patients. Like psychomotor dysfunction, it is an integral part of melancholia. Melancholic patients are preoccupied with thoughts of guilt, worthlessness, and helplessness, often so severely distorted and exaggerated as to dominate daily living.

Melancholia is a well-defined clinical picture that can be honed by laboratory tests, course of illness, and treatment response. Understanding the many putative mood disorders in the present classification as they relate to melancholia oVers an opportunity to define a common biology and to simplify and improve therapeutics.

A revival of the concept of a single manic-depressive illness with the depressed phase recognized as ‘‘melancholia’’ is also parsimonious and best fits the evidence. From this perspective, many of the disorders of mood that are described in psychiatric classifications can be considered melancholic illness.

Descriptions of individual patients with a depressive mood disorder offer rich imagery of the patients who meet the criteria for melancholia. The vignettes from Hopewell-Ash’s Melancholia in Everyday Practice (1934) oVer pictures before the present psychiatric classifications and modern therapies evolved.