Neuropsychiatry and Behavioral Neuroscience by Michael S Mega & Jeffrey L Cummings

Author:Michael S Mega & Jeffrey L Cummings
Language: eng
Format: epub
Publisher: Oxford University Press
Published: 2003-03-05T16:00:00+00:00

Depression

Clinical Manifestations of Depression

Depression is a broad term that encompasses changes in mood as well as a complex clinical syndrome (major P.201

depressive episode). Depression as a mood change typically includes sadness and anhedonia or an impaired ability to experience pleasure. In severe cases there are frequent thoughts of suicide or death; depression is frequently accompanied by feelings of guilt, helplessness, hopelessness, and worthlessness.

A major depressive episode is multidimensional (Table 14.1) and includes disturbances of mood, abnormalities of verbal expression, affective changes, motoric manifestations, cognitive alterations, motivational changes, neurovegetative disturbances (sleep, appetite, and sexual behavior), and neuroendrocrinologic changes. The mood alterations of a major depressive episode include sadness and anhedonia. Abnormalities of verbal expression include a delay in responding verbally, short verbal responses, a trailing off in verbal volume in the course of a sentence, slowness of speech, and a reduced initiation of conversation. In addition there is frequently a lack of emotional inflection of the voice (dysprosody). The patient frequently returns to themes of guilt, hopelessness, and worthlessness in the course of the conversation.

Affective alterations of depression include reduced facial mobility; eyebrows tend to be furrowed and drawn together, deepening the vertical furrow between them. Eye contact with the examiner is avoided and the patient may weep. Motoric manifestations of depression include retardation (or periods of agitation), catatonia, postural slumping, body immobility, and slowed movements, including walking.

Cognitive impairment is also present in depression (described in more detail below) and includes a poverty of associations, a tendency toward depressive thoughts, executive dysfunction, and disproportionate impairment of visuospatial skills. Motivational disturbances include reduced interest and difficulty in initiating new activities.

Neurovegetative abnormalities present in depression include alterations in appetite (usually reduced although occasionally increased) and sleep abnormalities; the latter include difficulty falling asleep, multiple awakenings, early morning awakening, and diminished rapid eye movement (REM) latency. Occasionally, patients sleep excessively. Patients often evidence diurnal variability in mood manifested by more severe sadness in the morning that remits partially by the afternoon and evening. Loss of libido is characteristic of depression.

Neuroendocrine disturbances notable in depression include failure to suppress endogenous cortisol secretion with administration of exogenous dexamethasone in the dexamethasone suppression test (DST) and abnormalities on the thyrotropin-releasing hormone (TRH) test.

Neuroimaging changes associated with depression include increased periventricular white matter abnormalities on computerized tomography (CT) or magnetic resonance imaging (MRI) and decreased cerebral blood flow or cerebral metabolism involving primarily the frontal regions (discussed in greater detail below) observed on single photon emission computerized tomography (SPECT) or positron emission tomography (PET).1,2,3

The presence of CNS disease may make the recognition of a depression syndrome more difficult and frequently modifies the manifestations of the disorder. Aphasic patients, for example, cannot voice the usual propositional expression of their internal emotional state; patients with right hemisphere injury or basal ganglia disease have dysprosodia and frequently lack the ability to inflect their voice. They lack the emotional vocal changes that allow the clinician to gauge the severity of the patient's mood changes. Patients with parkinsonism may have slowed movements, vocal changes, and facial hypomimia similar to depression without any corresponding mood abnormality.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.