CHAPTER 6 Depressive disorders
We all know what it means to feel sad and unhappy, and in English we often use the term ‘depression’ to describe that experience. We use this term to describe many states in which there are features which include unhappy mood but which also involve disruption of other functions such as thinking, self-esteem, sleep, perception of energy, sexual interest, appetite, the experience of pleasure generally and the ability to interact with other people. Depressive disorders are more common in women (lifetime prevalence about 11%) than men (lifetime prevalence about 6%). A summary of the diagnostic criteria for depressive disorders for DSM–IVTR and ICD–10 is presented in Table 6.1.
TABLE 6.1 Features of a depressive episode in adults according to DSM–IVTR and ICD–10
| DSM–IVTR (synopsis) Major depressive episode | ICD–10 (synopsis) Depressive episode |
|---|---|
| Five (or more) of the following symptoms (must include either (1) or (2)) on most days, for most of the day, over at least 2 weeks, associated with distress and impairment of functioning:
(9) recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation, or suicidal plan
Exclusions: |
Classification into mild, moderate or severe depression is determined by the number of items below which can be identified:
(1) depressed mood to a degree that is definitely abnormal for the individual, present for most of the day and almost every day, largely uninfluenced by circumstances, and sustained for at least 2 weeks
An additional symptom or symptoms from the following list should be present to give a total of at least four: |
Clinical features of depressive disorders
Changes in mood
These are predominantly an experience of emptiness rather than sadness (see Box 6.1). There is little or no capacity for the experience of pleasure (‘anhedonia’), a core feature of depressive disorders. The unpleasant mood tends to be present almost constantly, often with an exacerbation in the mornings and improvement in the evenings (‘diurnal mood variation’) and is associated with the ‘melancholic’ or ‘somatic’ subtype of depressive disorder (see Box 6.2). (Diurnal mood variation may also be evident during times of high emotional stress and is not a pathognomonic feature of depressive disorder.) Mood in depressive disorders tends to exhibit poor response to events or circumstances (loss of ‘reactivity’ of mood). Unpleasant arousal (anxiety) and anger are sometimes prominent.
Changes in thinking
Depressive disorders have an effect upon thought content and are often provoked by persistently negative and self-defeating patterns of thought about the self, the past and/or the future. Poor self-esteem is often prominent among these. Excessive guilt about actual or even imagined wrongdoings may develop and suicidal thoughts are common. The capacity to think may be significantly impaired (e.g. concentration, memory and comprehension) and executive cognitive functions (e.g. decision making, abstract thinking, changing set and problem solving) may also be affected. Severe impairment of thought function and physical spontaneity is called ‘psychomotor retardation’.
Psychotic depression
Hallucinations may occur and are often auditory in form. For example, the person may hear a voice making critical and disparaging remarks about them, in either the second or third person. Sometimes, the sufferer may experience olfactory hallucinations of their body emitting a foul odour (perhaps as it is perceived to decay). Psychotic depression is a particularly severe and destructive form of depressive illness and carries a high mortality rate from suicide.
Less ‘typical’ presentations
Not all people who suffer depressive disorders present initially with the features outlined above. This less typical presentation is called atypical depression (see Box 6.3) and may have implications for choice of treatment. Some notes regarding groups of patients with special elements in their depressive disorders are listed in Box 6.4.
BOX 6.4 Special groups and settings
