Depressive Illness
Depressive illness is a sustained, pervasive lowering of mood accompanied by a cluster of associated features such as loss of interest and pleasure, reduced energy, disturbed sleep and appetite, poor concentration, feelings of worthlessness or guilt, and in more severe forms, slowing of movement and thought or preoccupation with death. It goes well beyond ordinary sadness in both its persistence and its pervasive effect on the person's whole functioning.
This has traditionally been distinguished by severity and pervasiveness from ordinary low mood or sadness, and at its most severe can present with a striking, almost bodily quality of heaviness sometimes termed vital depression, or, at the furthest extreme, with such profound slowing that the person becomes mute and immobile, a state termed depressive stupor.
Also known as
- Vital hypochondriacal depression
- A severe pattern in which low mood is experienced as a profound physical, bodily heaviness or wrongness (a 'vital' quality) alongside prominent, often exaggerated preoccupation with physical health.
Recognition features
- A sustained, pervasive lowering of mood, present for most of the day, most days, over a period of weeks or longer
- Loss of interest and pleasure in activities previously enjoyed
- Associated features: disturbed sleep (often early morning waking) and appetite, poor concentration, reduced energy, feelings of worthlessness or excessive guilt
- In severe forms, a profound bodily heaviness (vital depression), pronounced slowing of movement and thought, or, at the extreme, depressive stupor (see the dedicated entry) with near-complete mutism and immobility
Eliciting it at interview
- Ask systematically about mood, interest, sleep, appetite, energy, concentration, guilt, and thoughts of death or self-harm, covering the full range of associated features
- Establish duration and pervasiveness, since a diagnosis of depressive illness requires the disturbance to be sustained rather than a brief or situational dip
- In severe presentations, assess carefully for psychomotor retardation and, in the most extreme cases, stupor, which represent psychiatric emergencies requiring urgent physical and nutritional assessment
Distinguishing features
- Differs from demoralization in that low mood, loss of interest, and other associated features extend pervasively across areas of life rather than remaining tied closely to a specific struggle
- Differs from an abnormal emotional reaction in its greater severity, persistence, and the presence of a full cluster of associated features rather than an isolated, disproportionate reaction
- Depressive stupor must be distinguished from other causes of stupor, given its profound severity and the urgency of appropriate management
Common misconceptions
- That depressive illness is simply an intensified version of ordinary sadness; its defining features include a specific cluster of associated symptoms (sleep, appetite, concentration, guilt) not present in ordinary low mood
- That a person with depressive illness must appear visibly sad; presentations such as vital depression or smiling depression can look quite different from a stereotypical tearful presentation
Related phenomena
Morbid Disorder of Emotion · Anhedonia · Psychomotor Retardation · Somatisation · Smiling Depression · Demoralization · Depressive Stupor · Extended Suicide · Irritability · Loss of Emotional Resonance · Reactivity of Mood
Related syndromes
Diagnostically relevant to
Major Depressive Disorder (links open the DSM-5 Learning Lab)
Practice this
For several weeks, a patient has experienced low mood present for most of the day, most days, loss of interest and pleasure in activities he previously enjoyed, disturbed early-morning waking, poor concentration, reduced energy, and feelings of worthlessness, all extending pervasively across every area of his life. What is this? · A patient facing a stressful, unresolved workplace dispute describes feeling low and discouraged specifically about work, but continues to sleep normally, eat well, enjoy time with friends and family, and maintain her usual concentration and energy in every other area of life. Before revealing the answer: is this a depressive illness? · A patient describes persistent low mood related to difficult circumstances. Before revealing the answer, decide what distinguishes a depressive illness from demoralization. · A patient describes persistent low mood. Before revealing the answer, decide how you would assess whether this represents a depressive illness. · Explain why distinguishing a depressive illness from demoralization matters clinically, given that both involve persistent low mood.
Illustration
For the past six weeks, a 53-year-old woman has woken most mornings at 4am unable to get back to sleep, has lost her appetite along with several pounds in weight, finds she can no longer concentrate on the crossword she once did daily, and describes a crushing sense that she has let her whole family down, none of which lifts even on days when good things happen.
References
- Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 6, 'Disorders of Emotion'.