Depression And The Medically Ill

An Integrated Approach

Gary Gary Rodin

• Publisher: Routledge
• Year: 2017
• ISBN:
  9781351569767
• Edition: 1
• Topic: Medizin
• Subtopic: Psychiatrie & geistige Gesundheit

Discusses the relationship between depression and medical illness and the diagnosis and management of depression in the medically ill. Covers methodological issues related to assessment and diagnosis of depression and analyzes psychological, social and biological factors associated with depression.

PART I

Clinical Presentation

1

Assessment and Diagnosis: I

The assessment of depression is fraught with difficulty because of the uncertain, and at times, arbitrary, boundaries among its clinical, subclinical, and nonpathological forms. Controversies about the conditions under which mood changes should be regarded as pathological (see Klerman, 1981) are heightened in the medically ill. In that context, clinicians are called upon to differentiate symptoms of major depression not only from those of less severe adjustment disorders and nonpathological reactions to illness, but also from those symptoms that are more direct manifestations of physical disease. These distinctions are problematic both because there is a realistic basis for feelings of sadness associated with a serious medical illness, and because vegetative symptoms such as anorexia or loss of energy may be the result of the physical illness.

It has been repeatedly demonstrated that the somatic symptoms that are used to diagnose depression are reported frequently by patients in general medical settings (Moffic & Paykel, 1975; Clark, Cavanaugh, & Gibbons, 1983) and with specific medical conditions including cancer (Bukberg, Penman, & Holland, 1984), endstage renal disease (Smith, Hong, & Robson, 1985; Craven et al., 1987), diabetes mellitus with metabolic dyscontrol (Lustman et al., 1986a), rheumatoid arthritis (Frank et al., 1988), Parkinson’s disease (Starkstein & Robinson, 1989) and multiple sclerosis (Krupp et al., 1988). Each of these illnesses is associated with a different constellation of symptoms that may confound the diagnosis of depression. For this reason, a substantial body of recent research has been directed toward identifying features that discriminate major depression from somatic symptoms that are produced directly by different physical illnesses. Some of this research is reviewed in this chapter and in the two which follow. The latter are devoted to the assessment and diagnosis of depression in the physically ill. This topic has been given extensive attention, not only because it is multifaceted, but also because diagnosing depression in this population remains a difficult task, even for experienced clinicians and researchers in the field.

Depressive Symptoms in the Medically Ill

Description of Measures

Due to their ease of administration and scoring, self-report measures of depressive symptoms are commonly used to study depression in the medically ill. In general, these instruments are composed of a standardized series of statements or questions based upon characteristic or typical symptoms of depression. The responses are scored either by the patient (self-report) or, less commonly, by the interviewer (observer-rated). These instruments have been termed “dimensional” measures because their scoring system usually allows a simple addition of items and the score reflects the overall severity of depressive symptoms on a continuous scale ranging from absent to severe. An assumption upon which these scales are founded is that depression is a continuous variable extending through their range (House, 1988). However, for many of the instruments, one or more cutoffs or threshold scores have also been defined to identify subgroups of patients (e.g., not depressed, mildly depressed).

Compared with unstructured clinical interviews, self-report inventories may be more reliable indicators of the presence and severity of depressive symptoms. The reliability of these instruments derives from the standardization of the questions or statements, their order of presentation, the wording and choices of answers, and the method of scoring. Unfortunately, these measures are of limited usefulness in the diagnosis of clinical depression (Boyle, 1985). Before discussing in more detail the general shortcomings and limitations of self-report instruments, we will describe the three instruments most frequently used to study depression in the medically ill—the Beck Depression Inventory (BDI), the Zung Self-Rating Depression Scale (SDS) and the Center for Epidemiologic Studies Depression Scale (CES-D).

Beck Depression Inventory (BDI)

The Beck Depression Inventory (Beck et al., 1961; Beck, Steer, & Garbin, 1988) is one of the most commonly used measures of depressive symptoms in medically ill samples. It is a 21-item, self-report questionnaire that includes 14 cognitive-affective symptoms and seven somatic ones. Each item (e.g., I feel like I am being punished) describes a symptom of depression with four accompanying descriptive statements ranging in intensity from absent, mild, moderate to severe. The respondent indicates which statement for each item best applies to him or her over the past seven days. Scoring the instrument involves the simple addition of the answers for the 21 items to give a total score ranging between 0 and 63. In addition to this summation score reflecting overall severity, Beck, Steer, and Garbin (1988) have provided cutoff scores for use in medically well samples. These cutoffs have been validated to define the following four groups: no depression (0-9); mild-moderate (10-18); moderate-severe (19-29); and severe (30-63) depressive symptoms.

The BDI has adequate reliability and validity (Beck, Steer, & Garbin, 1988) in medically well samples and has been used in several hundred studies since its inception (Steer, Beck, & Garrison, 1986). However, the evidence that the BDI can be used to quantify the construct of depressed mood with reasonable consistency should not be considered equivalent to its utility in identifying major depression. From an examination of the factor structure of the BDI, Louks, Hayne, and Smith (1989) found that whereas the instrument appears to measure the cognitive aspects of depression, its total score was not strongly related to the vegetative symptoms of depression that are an important clinical aspect of a major depressive episode.

The BDI has been widely used in medical settings, but only a small number of studies have examined the validity of this measure in these patients. One study by Clark, Cavanaugh, and Gibbons (1983) demonstrated adequate internal consistency for the BDI in a sample of general medical inpatients. In order to determine its diagnostic validity in 153 general medical inpatients, Schwab et al. (1967a) compared the BDI scores with results from clinical interviews and from an observer-rated measure of depressive symptoms, the Hamilton Rating Scale for Depression (HAM-D). They concluded that the BDI cutoff (i.e., >9) used in the general population to indicate at least mild depressive symptoms was also useful in their sample. Subsequent investigators have most commonly suggested that the threshold for case definition of depression should be increased in the physically ill. The need for a higher threshold is suggested by the increased frequency of both somatic symptoms (e.g., loss of energy), and of nonpathological depressive symptoms associated with adjustment to illness in physically ill patients. Unfortunately, there has been little agreement about what is the most appropriate cutoff score to screen for severe or clinical depression. Thresholds of > 9 (e.g., Smith, Hong, & Robson, 1985), >13 (e.g., Moffic & Paykel, 1975), and >17 (e.g., Rodin & Voshart, 1987) have been used to identify significant depression. The use of a similar cutoff by different investigators would certainly improve the comparability of studies, but little evidence exists to support strongly the use of any particular cutoff. Some investigators have wisely reported the case rates found using several different BDI cutoffs (e.g., Nielsen & Williams, 1980).

Zung Self-Rating Depression Scale (SDS)

The Zung Self-Rating Depression Scale (Zung, 1965, 1986) was constructed from verbatim reports of depressed patients. Statements most representative of the depressive symptoms were included in the 20-item scale (e.g., I feel downhearted, blue, and sad). When administered, the patient is asked to rate each item according to how often this symptom was experienced during the week prior to completing the questionnaire. The possible answers include: none or little of the time; some of the time; a good part of the time; and most of the time. The maximum possible raw score is 80.

The SDS has been found to have adequate concurrent validity compared with several other dimensional scales of depression. Construct validity has been demonstrated in studies that have shown a reduction in scores as patients recover from major depression (Zung, 1986). The average score on the scale in nondepressed samples drawn from the general population is 39 (Zung, 1986). A series of studies, which together include more than 1500 patients with depressive disorders, showed that the mean score of these patients is most commonly between 55 and 70 (Zung, 1986). These and other data led to the establishment of a cutoff score of either >50 or >55 to indicate significant depression, although Okimoto et al. (1982) provided evidence to support a cutoff of >60 to detect depression in elderly medical patients. The psychometric properties of the SDS have not been clearly established in patients with physical illness.

Center for Epidemiologic Studies Depression Scale (CES-D)

The Center for Epidemiologic Studies Depression Scale (Comstock & Helsing, 1976; Craig & Van Natta, 1976) is a self-administered 20-item questionnaire that contains statements, as do the BDI and SDS, corresponding to characteristic symptoms of depression experienced over the week prior to completing the scale. Each item in the questionnaire has a range of four response options based on how often during the past week the respondent experienced a symptom (e.g., rarely or none of the time, some or little of the time, occasionally or a moderate amount of the time, and most or all of the time). The score, which may range from 0 to 60, indicates the severity of depressive symptoms.

The CES-D has been most commonly used to screen for depressive symptoms in the general population. From these studies, it has been determined that a cutoff of > 15 is suggestive of at least mild depression. For example, Radloff (1977) has shown that the mean score in a normal population is approximately 8, and that about 20 percent of a normal population and 70 percent of a psychiatric population score above 15. In both normal and psychiatric samples, the instrument has been demonstrated to have very high internal consistency and adequate test-retest reliability. The diagnostic validity of this scale has not been stringently tested in medical samples.

Nonspecific Measures of Psychologic Morbidity

Several other measures have also been used to measure emotional distress in medical patients. The General Health Questionnaire (GHQ) (Goldberg, 1972) has been widely applied in medical settings. However, the GHQ is a measure of overall emotional distress and does not selectively focus on depressive symptoms. Similarly, the Symptom Distress Checklist (SCL-90-R) (Derogatis, 1983) has been used in medical inpatients. Although this inventory includes a depression subscale, the total score is most frequently reported, and the findings of the depression subscale are seldom described in full. Some have argued that measures of generalized distress are the most appropriate for use in the medical setting (Mayou & Hawton, 1986). This may be true, depending upon the purpose for which they are used. Studies using these less specific measures of psychologic morbidity are occasionally referred to in this text, but for the most part, we discuss in detail only those studies and measures that selectively focus on depression and depressive symptoms in the physically ill.

Limitations of Self-Report Measures

The absence of adequate validation of self-report measures in medically ill patients is a major limitation to their use in medical settings. Most problematic, when these measures are used with physically ill patients, is that they include somatic symptoms of depression that are confounded by the physical illness. For example, the Minnesota Multiphasic Personality Inventory (MMPI), which includes a depression subscale, has been used frequently in studies of patients with rheumatoid arthritis. Pincus et al. (1986) found that 70 randomly selected rheumatoid arthritis patients attending an arthritis treatment center had elevated scores on depression, hypochondriasis, and hysteria, three subscales of the MMPI. However, these authors also reported that the elevations on these subscales were almost entirely accounted for by a small number of items (e.g., loss of energy) which two-thirds of 117 rheumatologists rated as highly consistent with active rheumatoid arthritis itself. The investigators concluded that depres...

Table of contents

• Cover Page
• title
• copy
• dedication
• ack
• fmchapter
• Part I Clinical Presentation
• 1 Assessment and Diagnosis: I
• 2 Assessment and Diagnosis: II
• 3 Ambiguous Presentations of Depression
• 4 Course and Complications
• Part II Etiology and Pathogenesis
• 5 The Nature of Affect
• 6 Psychological Factors
• 7 Social Factors
• 8 Biological Factors
• Part III Treatment
• 9 Psychological Treatments
• 10 Somatic Treatments
• Conclusions
• Name_Index
• Subject_Index
• About the Authors