Depression in rheumatological diseases

3 Depression in rheumatological diseases B R E N D A McEVOY DeVELLIS

The onset of symptoms and eventual diagnosis of chronic disease typically cause emotional distress. In most cases this distress subsides over time as psychological adaptation to the condition occurs (Rodin et al, 1991). A significant minority of people, however, will develop less transient and more severe psychological distress that can result in additional disability and suffering. Like the majority of people with other medical illnesses, most people with rheumatological conditions adjust satisfactorily to both the diagnosis and the accompanying physical symptomatology and disability. This chapter concerns those people with rheumatological diseases who do not fare as well. Depression is the primary focus of the present chapter because it is the most common psychological disturbance associated with medical illness. In addition, depression is the psychological disturbance that has received the most study in rheumatology. Finally, depression can significantly increase the disability associated with a medical condition (Wells et al, 1989b; Pope and Tarlov, 1991; Rodin et al, 1991). Depression in the medically ill frequently goes undetected and untreated despite the availability of effective psychological, social, and pharmacological interventions (Rodin et al, 1991). Left untreated, depression in the medically ill can become progressively debilitating and interfere with optimal treatment of the medical illness (Attkisson and Zich, 1990). The presence of depression in rheumatological disease is particularly problematic because depression is often associated with somatic symptoms that overlap with or resemble symptoms of arthritis. To complicate the picture further, depression can lead to the amplification of somatic symptoms of arthritis, causing both physicians and patients to mistakenly attribute worsening symptoms, symptom reports and disability to worsening medical illness. This misattribution, in turn, can result in unwarranted regimen changes and overmedication (Katon and Sullivan, 1990). Finally, depression is associated with decreased physical activity, poor treatment adherence, and misutilization of health care services, all of which can adversely affect optimal treatment of rheumatological problems (Murphy et al, 1988; Johnson et al, 1992; Morrow et al, in press). Although rheumatologists are well aware of the potentially debilitating effects of the rheumatological diseases, they may be less aware of the severe functional declines associated with depression, even in the absence of other Bailli~re's ClinicalRheumatology--

Vol. 7, No. 2, June 1993 ISBN0-7020-1710-8

241 Copyright9 1993,by BailliereTindall All rights of reproductionin any formreserved

242

B.M. DeVELLIS

health conditions (Klerman and Weissman, 1992). Depression is a debilitat-. ing and often life-threatening disorder. In one of the most comprehensive studies of the impact of depression on functioning, Wells et al (1989b) found that people with a depressive disorder or depressive symptoms, in the absence of comorbidity, had functioning comparable to or worse than people with one of eight other chronic medical conditions including arthritis. Patients with depressive symptoms reported more days in bed than did those with arthritis, hypertension, diabetes, angina, gastrointestinal problems, or back problems. Only patients with advanced coronary artery disease reported more days in bed than did patients with depressive symptoms. Finally, when depressive symptoms occurred in combination with one of the eight chronic conditions studied, declines in functioning were additive. Thus, to maximize patient functioning, rheumatologists must be alert for depressive comorbidity among their patients and be prepared to provide appropriate treatment or referral. The remainder of this chapter focuses in greater detail on a series of issues that are potential sources of confusion or ambiguity concerning depression and rheumatological disease. It first describes ways that depression has been defined and measured in the rheumatology literature. The aim is not to provide a detailed review of psychiatric nomenclature or psychometric principles but to sensitize readers to definitional distinctions so that they can more fully assess the strengths and weaknesses of this literature. Next, the discussion focuses on common conceptual, measurement and methodological problems that make interpretation of depression prevalence rates among those with rheumatological diseases difficult. A summary of prevalence studies relevant to depressive disorders and depressive symptoms among people with rheumatological diseases follows. Studies employing both community and clinic samples are included in the review. The chapter concludes with recommendations for the screening and treatment of depressive disorders in people with rheumatological diseases. DEFINING AND MEASURING DEPRESSION Depressive disorders

Three major systems are used for the classification of psychiatric morbidity: the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III; American Psychiatric Association, 1980); the International Classification of Diseases, ninth revision (ICD-9; World Health Organization, 1977); and the Research Diagnostic Criteria (RDC) (Spitzer et al, 1978). In practice, psychiatrists, clinical psychologists or other mental health clinicians arrive at diagnoses compatible with these classification systems through comprehensive clinical interviews (Rodin et al, 1991). Of the three systems, the DSM-III is the most widely used system in North America for classifying mood disorders. DSM-III was revised in 1987 (American Psychiatric Association, Committee on Nomenclature and Statistics, 1987) and this revision is referred to as DSM-III-R,

D E P R E S S I O N IN R H E U M A T O L O G I C A L D I S E A S E S

243

According to DSM-III-R, the two major types of mood disorders are bipolar disorders and depressive disorders. Bipolar disorders (also referred to as manic-depressive illness) are not addressed in this chapter because they are rare and there is relatively little research related to them in either the rheumatology or medical illness literatures. The depressive disorders consist of major depression, dysthymia and depressive disorder not otherwise specified. According to DSM-III-R, two other non-mood disorders have depression as a predominant feature: organic mood disorder and adjustment disorder with depressed mood (Rodin et al, 1991). Much of the research in arthritis has focused on major depression and dysthymia. These disorders are appropriate for study because of their high prevalence rates in the general population and in the practices of general medical physicians. In addition, both are associated with impaired functioning (Attkisson and Zich, 1990). A diagnosis of major depression, according to DSM-III-R criteria, requires the occurrence of one or more major depressive episodes. A major depressive episode requires the presence of at least five of the following symptoms for at least 2 weeks: depressed mood; markedly diminished interest and pleasure in activities; significant weight loss or gain; insomnia or hypersomnia; psychomotor agitation or retardation; fatigue or loss of energy; feelings of worthlessness or guilt; diminished ability to think or concentrate or indecisiveness; and recurrent thoughts of death or suicide. One of the first two symptoms--depressed mood o r diminished interest or pleasure--must be included among the minimal five symptoms to meet the diagnostic criteria for a major depressive episode. This means that a person can be diagnosed with a major depressive episode without reporting sadness if they report an inability to experience pleasure. Major depressive episodes may be classified as mild, moderate, or severe without psychotic features or severe with psychotic features. Symptoms clearly due to a physical condition do not satisfy the diagnostic criteria. Therefore, if a person with a rheumatological disease has a symptom that is dearly attributable to that disease, such as loss of energy, then this symptom would not be counted as one of the five symptoms necessary to meet diagnostic criteria for major depressive episode. If two or more major depressive episodes are separated by at least 2 months, during which time there is a return to usual functioning, the disorder is referred to as major depression, recurrent. If a major depressive episode has lasted for two consecutive years without an interruption of at least 2 months, then it is classified as major depression, chronic. The second type of depressive disorder, dysthymia, is a chronic but less severe disorder characterized by depressed mood for most of the day during the majority of days over at least a 2-year period. In addition to the symptom of depressed mood, at least two of the following symptoms must be present for a diagnosis of dysthymia: poor appetite or overeating; insomnia or hypersomnia; low energy or fatigue; low self-esteem, poor concentration or difficulty making decisions; feelings of hopelessness. If a person's symptoms meet the criteria for major depression, they are not classified as dysthymia. If individuals with pre-existing dysthymia develop a major depressive

244

B.M.

DeVELLIS

episode, they receive the diagnoses of both major depression and dysthymia, a condition sometimes referred to as 'double depression'. The 1987 DSM-III-R specifies two subtypes of dysthymia not included in the earlier classification system (DSM-III): primary dysthymia and secondary dysthymia. Of particular interest is that, in secondary dysthymia, the mood disturbance appears related to a pre-existing chronic physical disorder whereas in primary dysthymia the mood disturbance is not related to a pre-existing, physical disorder. The diagnosis of depressive disorder not otherwise specified is assigned to people who have depressive episodes that do not reach threshold for a diagnosis of major depression or dysthymia. Disorders assigned to this category also have been referred to as subclinical depression. Although this diagnosis would seem relatively benign, as will become evident later in this chapter, it, too, is associated with morbidity and functional limitations among people with arthritis. The diagnosis of adjustment disorder with depressed mood is considered an incomplete depressive reaction to an identifiable psychosocial stressor (e.g. job loss; onset of medical illness). To meet diagnostic criteria for adjustment disorder with depressed mood, this depressive reaction must occur within 3 months of the stressor and persist for no more than 6 months. If the reaction meets the criteria for one of the depressive disorder diagnoses, however, then it is assigned to that diagnosis. If the reaction persists for more than 6 months, then the diagnosis is changed to another mental disorder (e.g. depressive disorder not otherwise specified). DSM-III-R requires that physicians confronted with a depressed patient rule out organic mood syndrome. Organic mood syndrome can resemble a major depressive episode but is due to a specific organic aetiological factor (Andreasen and Black, 1991). Some rheumatological diseases such as systemic lupus erythematosus and temporal arteritis may present with prominent depressive symptoms that are organically based. In addition, medications used to treat rheumatological diseases, such as corticosteroids or methotrexate, can induce organic mood syndrome. Structured and semi-structured diagnostic interviews corresponding to one or more of the three major classification systems have been developed. These interviews have standardized criteria for the diagnosis of depressive disorders as well as for other types of psychiatric illness. Use of diagnostic interviews by properly trained personnel provides the best approach for identifying cases of major depression and dysthymia for research purposes. Four of the diagnostic interviews, the Standardized Psychiatric Interview (SPI; Goldberg et al, 1970), Present State Examination (PSE; Wing et al, 1974), Schedule of Affective Disorders and Schizophrenia (SADS; Endicott and Spitzer, 1978) and Structured Clinical Interview (SCID; Spitzer et al, 1992) are administered by trained clinicians. The Diagnostic Interview Schedule (DIS) (Robins et al, 1981) was developed specifically for largescale epidemiological studies in the USA. Advantages of this highly structured interview are that it can be administered by trained lay interviewers. It takes 60-90 minutes to administer, however (Burnam and Wells, 1990).

DEPRESSION IN RHEUMATOLOGICAL DISEASES

245

Depressive symptoms Depressive symptoms can be assessed through self-administered questionnaires, clinician-administered rating scales and diagnostic interviews. Depressive symptom self-report scales contain multiple items that represent common symptoms of depression. Respondents indicate the extent to which they have experienced each symptom over a specified period of time (e.g. the last week) and a total depressive symptom score is computed by simple addition. This sum reflects the overall severity of depressive symptoms on a continuum from absent to severe (Rodin et al, 1991). A great deal of research and effort has gone into the development of efficient and reliable standardized symptom report measures. Administration of these types of scales to literate people in community and clinical settings is quick and inexpensive compared to the time and cost associated with conducting diagnostic interviews. The Center for Epidemiological Studies--Depression measure (CES-D; Radloff, 1977), the Beck Depression Inventory (BDI; Beck et al, 1988), and the depressive symptoms subscale of the Arthritis Impact Measurement Scales (AIMS; Meenan et al, 1980) are depressive symptom scales that have been used frequently in studies of people with rheumatological diseases. The CES-D was originally developed for use in large, population-based epidemiological studies. It has demonstrated excellent psychometric properties in these applications (Radloff and Locke, 1986). It consists of 20 items, each describing a specific symptom of depression. The respondent is asked to indicate the frequency with which each symptom has been experienced in the past week. The BDI is a 21-item measure that assesses the intensity and severity of depressive symptoms. The AIMS depression scale consists of six items that ask about how often the respondent experiences a number of negative mood states. The validity of the CES-D and the BDI have been assessed in medically well populations using structured diagnostic interviews as validators. The AIMS depression measure has not been validated in relation to diagnostic interviews. Strong correlations between AIMS depression and CES-D scores, however, have been reported (DeVellis and Blalock, 1992; Hawley and Wolfe, 1992). These depressive symptom scales are helpful in identifying the prevalence of symptomatology and distress among different populations and for identifying and studying factors that influence levels of symptomatology. Self-report depressive symptom scales also are useful for identifying people who might be at risk for having a depressive disorder. Depressive symptoms, however, frequently occur with psychiatric conditions other than depressive disorders (e.g. adjustment disorders, schizophrenia, organic mood disorders). Because depressive symptom scales do not have questions that exclude people with other psychiatric disorders, they have lower specificity than diagnostic interviews (Murphy, 1990). A related problem is that scores may be elevated among people who are experiencing very transient distress but who are generally well adjusted. Severity of depressive symptoms and changes in depressive symptoms are sometimes quantified by mental health clinicians using standard observer

246

B.M. DeVELLIS

rating scales. These types of scales are used frequently to assess responses of patients to treatment interventions. The Hamilton Rating Scale for Depression ( H R S D ; Hamilton, 1960), one of the oldest and most widely used, has been criticized and revised by a n u m b e r of researchers (Miller et al, 1985; Ferguson and Tyrer, 1989).

Table 1. Common methods for diagnosing depressive disorders or identifying depressive symptoms. Relevant citations

Type of method

DSM III WorldHealth Nosologies, criteria, DSM III-R Organisation,1977; and/or diagnostic ICD-9 Spitzer et al, 1 9 7 8 ; algorithms for RDC American Psychiatric psychiatric Association, 1 9 8 0 , classification 1987 SPE Goldberg et al, 1970; Structuredor semiPSE Wing et al, 1974; structured interviews SADS Endicott and Spitzer, for arriving at clinical SCID 1978; Robins et al, diagnoses DIS 1981; Spitzer et al, 1992 ~CES-D Radloff, 1977; Meenan Self-report of frequency BDI et al, 1980; Beck et and/or intensity of AIMS-D al, 1988 depressive symptoms HRSD

Hamilton, 1960; Miller et al, 1985; Ferguson and Tyrer, 1989

Interview-based clinician rating of depressive symptoms

Purpose Diagnosis of depressive disorders

Clinical diagnosis, primarily for research

Research, including outcome evaluations, surveys and population-based studies Clinical research or treatment evaluation

A final way that investigators derive depressive s y m p t o m measures is from data obtained through diagnostic interviews (Johnson et al, 1992). This results when participants report some but not enough depressive s y m p t o m s to reach criteria for a diagnosis of m a j o r depression or dysthymia. Although D S M - I I I - R allows for classifying these people as having depressive disorder not otherwise specified, m a n y investigators prefer to refer to this group of people as having depressive symptoms or subclinical depression or minor depression.

P R E V A L E N C E OF DEPRESSION IN R H E U M A T O L O G I C A L DISEASES There are conceptual, definitional, m e a s u r e m e n t , and methodological problems that m a k e it difficult to interpret the literature on the prevalence of depression in rheumatoiogical diseases. These problems are briefly reviewed before examining specific prevalence findings.

D E P R E S S I O N IN R H E U M A T O L O G I C A L D I S E A S E S

247

Confusion between depressive disorders and depressive symptoms Depressive symptom scales were never intended as diagnostic instruments and are not adequate for diagnosing depressive disorders (Rodin et al, 1991). Despite significant differences between the diagnosis of a depressive disorder as determined by diagnostic interview and an enumeration of the frequency or severity of depressive symptoms as determined by self-report symptom scales, the rheumatology literature sometimes fails to acknowledge their non-equivalence. The confusion may stem, in part, from the common practice of assigning 'cut points' to self-report symptom scores, resulting in respondents being classified as above or below some criterion level of depressive symptomatology. Regrettably, those above the criterion score may be referred to by authors as 'depressed' without further elaboration. The practice of using cut-off points is helpful in presenting and interpreting depressive symptom data, particularly if one wants to describe numbers of people who have many depressive symptoms versus those who have few. Furthermore, some of these cut points have been evaluated against confirmed cases of depressive disorder for members of the general population and sensitivity and specificity levels identified. This type of validation work has not been done for populations of people with medical illness, however. As shown in the next section, the confounding of some measures of depressive symptoms with symptoms of rheumatological diseases may render cutoff points developed from studies of depressive symptoms in the general population inapplicable to people with rheumatological disease.

Confounding of depressive and rheumatological symptoms Some of the somatic manifestations of depression, such as fatigue and sleep difficulties, are also typical manifestations of certain rheumatological disease processes. A number of researchers have studied the extent to which the rheumatological disease process may influence responses to somatic items on the CES-D and BDI scales (Pincus et al, 1986; Blalock et al, 1989; Peck et al, 1989; Callahan et al, 1991). They conclude that inclusion of these types of items cn self-report questionnaires may inflate estimates of the prevalence and severity of depressive symptoms among people with rheumatological diseases. The one study, however, that assessed the level of inflation among people with rheumatoid arthritis (Blalock et al, 1989) found that it was modest. Suggested remedies to this problem include (1) eliminating the somatically related items and (2) increasing the threshold (cut-off points) for labelling symptoms as suggestive of significant problems. Elimination of somatic items could lead to some underestimation of depressive symptoms among those patients whose increasing psychological distress manifests itself in increased somatic complaints. Raising the cut-off scores, however, addresses the issue of somatic item ambiguity less directly than eliminating tl~e items. Researchers most often think of the symptom confounding problem in the context of self-administered scales but it also poses potentia! problems for

248

B.M.

DeVELLIS

structured diagnostic interviews. Although the Present State Examination instructs the interviewer to exclude symptoms that are apparently caused by a physical illness, it does not provide criteria for making this decision (Rodin et al, 1991). Thus, the interviewer may be left with the dilemma of deciding whether a certain level of fatigue or sleep disturbance is attributable solely to medical illness or to a depressive overlay that is amplifying the arthritis symptom. The Diagnostic Interview Schedule (DIS) includes a decision tree for the interviewer. This decision process, however, relies heavily on patient reports about whether or not their physician attributed specific somatic symptoms to a medical illness or medication. This assumes that the patient has been given information about each symptom by the physician and that the patient's interpretation and recall of that information are correct (Rodin et al, 1991). Time frames for different prevalence measures

Incidence is an enumeration of those people who experience a first-ever episode of a given disease or condition within a defined period of time. Prevalence is an enumeration of all people who have a given disease or condition in a given population at a designated time (Murphy, 1990). Annual prevalence refers to the number of people with the condition at any time during the year in question, regardless of whether the onset of the condition occurred prior to that year, as long as it extends into the year in question. Lifetime prevalence refers to the total number of persons who have had the condition for at least part of their life (Last, 1983). There are many different ways of framing prevalence rates and the way that those rates are framed will affect the rates reported. Depressive symptom measures tend to ask respondents about symptoms they have experienced during the last week and are thus focused on identifying 'current clinical state'. This makes sense for studies designed to monitor symptoms over time, either to understand their natural course or to assess the effect of intervention. This means, however, that a description of the prevalence of depressive symptoms reported in a study may be for a 1-week period, which is clearly not comparable to an annual or lifetime prevalence rate. The DIS, on the other hand, assesses both lifetime and current prevalence by first asking if the person has ever experienced certain combinations of symptoms and then enquiring about the presence of current symptoms (Murphy, 1990). A diagnosis of major depressive disorder, however, requires that the respondent has had a major depressive episode of no shorter than 2 weeks and the diagnosis of dysthymia requires the presence of symptoms for at least 2 years. Thus, there can be wide discrepancies in the timeframes for symptoms and disorders reported in the literature. Community vs clinic samples

Most studies of depression in rheumatology have been carried out with convenience samples of patients treated in clinical settings. These studies

DEPRESSION IN RHEUMATOLOGICAL DISEASES

249

can be helpful in understanding the prevalence of depression in specific clinical settings and in identifying factors that are associated with depression among these patients. They do not, however, provide much of a sense of the true prevalence of depression among people with rheumatological diseases. There are a number of reasons for this. Depression is associated with more frequent utilization of non-psychiatric medical services (Attkisson and Zich, 1990). Therefore, people with depression may have a greater chance of being over-represented in samples of people identified through clinics. Clinic samples may also exclude people who have poorer access to medical care and over-represent those more severely affected with rheumatological conditions. Finally, samples drawn from the clinic frequently lack adequate comparison groups of people both with and without other medical disorders (Wells et al, 1989a). Prevalence: clinical samples

Most research on depressive disorders and depressive symptoms in rheumatological diseases has been done using samples of patients identified through clinics or physician practices that specialize in the diagnosis and treatment of rheumatological diseases. Although there are over 100 conditions which can be classified as rheumatic diseases, larger-scale research efforts have focused on psychological sequelae in primarily five of these conditions: rheumatoid arthritis (RA), juvenile rheumatoid arthritis (JRA), systemic lupus erythematosus (SLE), fibromyalgia, and osteoarthritis (OA). Excellent reviews and critiques of this research can be found in 11 major papers published during the past decade (Achterberg-Lawlis, 1982; Baum, 1982; Anderson et al, 1985; Bradley, 1985; Lerman, 1987; Creed, 1990; Creed et al, 1990; Hnatiuk and Duncan-Jones, 1990; Wolfe, 1990; Quirk and Young, 1992; Young, 1992). Taken together, these reviews provide a comprehensive examination of the relevant literature. Although there are some exceptions (e.g. Cassileth et al, 1984), the majority of studies suggest that there is a greater prevalence of depressive symptoms and depressive disorders among clinical samples of people with rheumatological diseases than in the general population. The level of psychological disturbance, however, is comparable to that found among clinical samples of people with other chronic medical conditions. Another notable conclusion is that rheumatological disease severity and status have, at most, a very weak direct relation to the presence of depressive disorders and level of depressive symptoms. As discussed in other chapters of this book, depressive disorders and symptoms among people with rheumatological diseases are influenced more by pain, socioeconomic factors, and social and other psychological resources, such as social support, a sense of control, illness intrusiveness and coping, than by disease severity itself. A final conclusion is that more well designed studies with adequate comparison groups and representative samples of people with rheumatological diseases are needed. A lack of such studies impedes a clear understanding of the prevalence of psychological disturbance among people with rheumatological diseases.

250

B.M. DeVELLIS

Three studies using clinical samples are reviewed below in more detail. These are large-scale recently completed or published studies and were not addressed by the previously discussed reviews. Hawley and Wolfe (1992) report the results of multiple administrations of the AIMS depression scale to 6608 rheumatic disease patients seen at an arthritis clinic in the midwestern part of the USA. They found that patients with fibromyalgia had significantly greater levels of depressive symptoms than patients with RA and that R A patients, in turn, had more depressive symptoms than patients with OA of the hand. Katz and Yelin (in press) recently assessed the prevalence of depressive symptoms in people with R A over a period of 3 years using the Rheumatoid Arthritis Panel Study data. This panel of people with R A was originally constructed in 1982 by randomly selecting 50 rheumatologists practising in Northern California. The 40 rheumatologists who participated listed all of their patients with R A who presented at their offices during a specified 1-month period. A total of 822 (97%) of the patients so identified agreed to participate. Depressive symptoms were assessed in 1986, 1988, 1989, and 1990 by telephone interview using the short form of the Geriatric Depression Scale (GDS; Alden et al, 1989). The 15-item short form, which assesses symptoms over the past week, has a simple 'yes/no' response format, minimizes questions related to somatic aspects of depression, and has been used successfully with younger as well as older populations. A cut-off point of 7 or greater was used to define the presence of depressive symptoms. Katz and Yelin found that in any one year, 15-17% of people with R A reported depressive symptoms that equalled or exceeded the cut-off point of 7. Furthermore, almost 4% equalled or exceeded the cut-off point every year and over 29% equalled or exceeded the cut-off point in at least one year. Additionally, the presence of depressive symptoms in one year greatly increased the probability of depressive symptoms in future years. To put these findings in perspective Katz (personal communication, 1992) has provided data on a comparison group panel of people without R A who were given the GDS between 1989 and 1991. The proportion of these people who exceeded the cut-off point of 7 between 1989 and 1991 ranged from 3% to 5%. Finally, respondents with RA and depressive symptoms reported 5.8-7.3 more days spent in bed during the previous month than did those respondents with RA who did not equal or exceed the cut-off point of 7. These findings are consistent with those of Well's et al (1989b), reported at the outset of this chapter: that is, the effects of depressive symptoms and chronic medical conditions are additive. The Medical Outcomes Study is a large recently completed study of patients' outcomes in competing systems of medical care (Stewart et al, 1989). A total of 362 medical providers were included in the sample. To study the mental health of people with chronic conditions, including selfreported arthritis, 9385 patients who visited one of the 362 physicians during a 9-day period in 1986 completed questionnaires. Depressive symptoms during the past month were included in the questionnaire but am reported as part of a larger measure of mental health that also assessed anxiety and feelings of positive well-being during the previous month. People with

D E P R E S S I O N IN R H E U M A T O L O G I C A L D I S E A S E S

251

arthritis had poorer mental health than did people in either of two comparison groups. The first comparison group consisted of patients with none of the chronic conditions studied. The most common reasons for physician visits in the comparison group were self-limiting acute medical problems and general examinations. Four per cent of the patients in this comparison group were seeing their physicians for depression or family problems. The second comparison group was made up of 2008 adults sampled to represent the US population in general. This is an important comparison group because of findings from other studies that more people with depressive symptoms are found in clinical samples. The mental health of people with arthritis was poorer than that of people in either comparison group even after controlling for sociodemographic characteristics and medical comorbidity and despite the fact that those patients who were seeing their physicians for depression were left in the patient comparison group. The mental health scores of patients with arthritis in this study were comparable to patients with congestive heart failure, chronic lung problems, gastrointestinal disorders and angina. Prevalence: community studies Data from the National Institute of Mental Health Epidemiologic Catchment Area (ECA) study provide the best estimates of the prevalence of depression in the United States (Weissman et al, 1988). Because of the scope of this study and the care with which it was conducted, it warrants description in some detail. In addition, this study addresses the relation between depression and self-reported arthritis in a general population. A probability sample of over 18 000 adults aged 18 years or older living in one of five communities (New Haven, CT; St Louis, MO; Baltimore, MD; Durham, NC; and Los Angeles, CA) was studied. The Diagnostic Interview Schedule (DIS) was administered to assess depressive disorders and depressive symptoms as well as other psychiatric diagnoses. Depressive episodes in response to bereavement were excluded unless they lasted a year or more. The mean 1-year prevalence for major depressive disorder across the five sites was 2.6% and the lifetime prevalence was 4.4%. The mean lifetime prevalence rate for dysthymic disorder across the five sites was 3.1%. Both major depression and dysthymia were more prevalent among women than men. Lifetime prevalence for major depression and~or dysthymia was 6% (Johnson et al, 1992). Participants who met at least two of the symptom group criteria from DSM-III but who did not meet diagnostic criteria for a depressive disorder were referred to as having depressive symptoms indicative of subclinical depression. Lifetime prevalence for this 'depressive symptoms' group was 23.1%. Johnson et al (1992) compared the percentage of adverse outcomes among the three groups: (1) major depression and/or dysthymia, (2) depressive symptoms, and (3) no depression. The last group consisted of people who met none or only one of the DSM-III symptom criteria for major depressive episode in their lifetime. The adverse outcomes compared included: service utilization (emergency room use or consultation with a

252

B.M.

DeVELLIS

physician other than a psychiatrist for emotional problems), psychotropic medication use, time lost from work, and suicide attempts. People with major depression and/or dysthymia had significantly greater adverse outcomes than did those with depressive symptoms. Those with depressive symptoms, in turn, had significantly greater adverse outcomes than did the non-depressed group. This suggests that depressive symptoms, even in the absence of depressive disorders, put people at risk for adverse outcomes. Wells et al (1989a) used data collected at the Los Angeles site of the ECA study to estimate the sex- and age-adjusted prevalence of mood disorders (major depression, dysthymia, or bipolar disorder) in a general population sample of people who identified themselves as ever having arthritis (18.6%). These people had an increased adjusted prevalence of lifetime (14.3%) and current (11.3%) mood disorders relative to people with no chronic conditions who had a lifetime and current prevalence of 6.9% and 4.4%, respectively. (These mood disorder prevalence figures include bipolar as well as depressive disorders but bipolar cases are rare and probably do not affect the figures significantly or differentially.) People with arthritis also had an increased prevalence of lifetime and current anxiety disorders and lifetime substance abuse disorders relative to the no-chronic-conditions group. These findings were generally comparable to data for groups with the other chronic conditions studied: diabetes, heart disease, high blood pressure and chronic lung disease. In another series of analyses of the Los Angeles ECA data, Wells et al (1988) compared the presence of any psychiatric disorder (both for 6-month and lifetime prevalence) among nine groups of people: those with one of eight chronic conditions including arthritis and people with no medical conditions. The presence of a chronic medical condition was significantly associated with lifetime and recent psychiatric disorder even after controlling for age, sex, ethnicity, education, marital status and job status. Arthritis (as well as cancer, chronic lung disease, neurological disorder, and heart disease) was strongly associated with psychiatric disorder. Furthermore, people who reported that they were currently under treatment for arthritis had a much higher prevalence of psychiatric disorder than did people who reported that they currently had arthritis but were not currently under medical treatment for it. Strengths of the Epidemiologic Catchment Area studies include (1) its carefully selected community sample and (2) use of the Diagnostic Interview Schedule to assess the presence of depressive disorders and depressive symptoms. A weakness of these studies is that they categorized people as having arthritis through self-report. A recently completed study used confirmed diagnoses of rheumatological disorders in a community sample (Cook et al, submitted). This study, however, focused on the prevalence depressive symptoms rather than depressive disorders. Cook et al (submitted) identified a sample of low-income residents of a rural county in the southern area of the United States with household incomes of no more than 187.5% of the poverty level. Study participants were recruited primarily through community sources and the use of a quota sampling strategy yielded equal numbers of men and women, and blacks and

253

DEPRESSION IN RHEUMATOLOGICAL DISEASES

whites. Participants were people who initially identified themselves as having arthritis. Confirmation of arthritis was achieved by one of these methods: (1) identification of a prior diagnosis from a physician experienced in diagnosing and treating rheumatological diseases, (2) a diagnosis from a primary care physician accompanied by a rheumatologist's review of appropriate records in support of that diagnosis, or (3) a physical examination and diagnosis by a rheumatologist, specifically for the study. Of the initial group, all of whom self-reported arthritis, in only 1.4% was the diagnosis proven incorrect. Table 2. Percentages of study participants meeting or

exceeding progressively more stringent CES-D cut-off scores for depressive symptoms. CES-D cut-off score

Osteoarthritis (n = 128) Rheumatoid arthritis ( n = 44)

16

17

23

47.7 34.1

43.7 31,8

23.4 15.9

Participants were administered the CES-D in their homes. Table 2 shows the percentage of participants whose CES-D scores equalled or exceeded cut-off scores of 16, 17 or 23. In the general US population, a cut-off score of greater than 15 is considered indicative of at least mild depression. Therefore, these results suggest a greater prevalence of depressive symptoms among a community population of people with known rheumatological disease. Another important conclusion that can be drawn from this study is the relative accuracy with which people were able to report that they had a rheumatological disease even when it had never been previously diagnosed by a physician.

Prevalence: summary The preponderance of the findings suggest that depressive disorder and depressive symptoms are more prevalent among people with some of the more common rheumatological diseases than among people without serious, chronic diseases. This increased prevalence is, in general, similar to that found for other serious, chronic diseases. The presence of depressive symptoms even in the absence of a diagnosable depressive disorder places people at risk of adverse outcomes in terms of functioning. Finally, despite the conclusion that a significant minority of people with rheumatological diseases suffer from depressive disorders and symptoms, the majority of such patients do not.

Detection of depression in rheumatological practice No studies of the accuracy with which rheumatologists detect depressive disorders or symptoms in their patients were identified. The ability of

254

B.M. DeVELLIS

primary care physicians to detect depression in primary care settings, however, has been the subject of a great deal of study (e.g. see Attkisson and Zich, 1990). Many of these studies have used the DIS or other rigorous diagnostic criterion measures to assess accuracy of primary care physicians' detection of depression. The results of this research have shown that physicians frequently fail to detect depressive disorders and significant depressive symptoms in their patients (Attkisson and Zich, 1990). Rodin et al (1991) report that depressed medical patients frequently do not report emotional symptoms to their physicians unless the physician inquires about them specifically. Rodin further suggests that some physicians of patients with serious illnesses mistakenly assume that depressive symptoms are expected and understandable reactions and therefore do not warrant treatment. In addition, some physicians are unaware of the important advances that have been made in treating depressive disorders and symptoms. Finally, many physicians and patients are unaware of the disabling consequences of depressive disorders and symptoms even in the absence of medical comorbidity and mistakenly attribute functional declines to the rheumatological disease. None of these conclusions and suggested explanations for the underdetection and treatment of depression, however, is based on studies of rheumatologists and their patients. Additional research is needed to determine the specificity and sensitivity with which rheumatologists' clinical judgements identify depressive disorders and symptoms in their patients, relative to established diagnostic criteria. If this research indicates that clinical judgement is inaccurate, then brief screening instruments with acceptable accuracy among this population must be identified.

CONCLUSION In the absence of any medical comorbidity, depressive disorders and even depressive symptoms have devastating effects on social, family and vocational functioning. When depressive disorders or symptoms co-occur with serious, chronic medical illnesses, functional declines are additive. Compared to the general population, the prevalence of depressive disorders and symptoms appears to be higher among people with rheumatological diseases. Rheumatologists, therefore, should be alert for depressive comorbidity among their patients and must guard against mistakenly attributing the additive effects of these comorbid conditions to worsening primary medical illness. Study after study has reported that the direct effects of rheumatological disease status and severity contribute minimally to the presence or absence of depressive disorders or to the level of depressive symptoms. In addition, studies have repeatedly shown that many people with rheumatological disease do not experience depressive disorders or symptoms. This means that factors other than disease severity and status influence depression; many of these factors are discussed in other chapters of this volume.

DEPRESSION IN RHEUMATOLOGICAL DISEASES

255

Acknowledgements Preparation of this chapter was supported in part by Multipurpose Arthritis Center Grant AM 30701 from the National Institutes of Health. I thank Susan Blalock, PhD, Robert F. DeVellis, PhD, Mary Ann Dooley, MD, Jo Anne Earp, ScD, Leila Gupta, MSW, MPH, Godfrey M. Hochbaum PhD, Lisa Amaya Jackson, MD, Sarah Kobrin, BA and Rosa Walker, MD, MSPH, for their comments on earlier drafts of this manuscript.

REFERENCES Achterberg-Lawlis J (1982) The psychological dimensions of arthritis. Journal of Consulting and Clinical Psychology 50: 984-992. Alden D, Austin C & Sturgeon R (1989) A correlation between the Geriatric Depression Scale Long and Short Forms. Journal of Gerontology 44: 124-125. American Psychiatric Association (1980) Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III). Washington, DC: American Psychiatric Association. American Psychiatric Association, Committee on Nomenclature and Statistics (1987) Diagnostic and Statistical Manual of Mental D&orders, Revised Third Edition (DSM-III-R), pp 111-112, 213-233,329-331. Washington, DC: American Psychiatric Association. Anderson KO, Bradley LA, Young LD et al (1985) Rheumatoid arthritis: review of psychological factors related to etiology, effects, and treatment. Psychological Bulletin 98: 354-387. Andreasen NC & Black DW (1991) Introductory Textbook of Psychiatry, pp 189-225. Washington DC: American Psychiatric Press. Attkisson CC & Zich JM (eds) (1990) Depression in Primary Care: Screening and Detection, pp 1-11. London: Routledge. Baum J (1982) A review of the psychological aspects of rheumatic diseases. Seminars in Arthritis and Rheumatism 11: 352-361. Beck AT, Steer RA & Gabin MG (1988) Psychometric properties of the Beck Depression Inventory: twenty-five years of evaluation. Clinical Psychology Review 8: 77-100. Blalock SJ, DeVellis RF, Brown GK & Wallston KA (1989) Validity of the Center for Epidemiological Studies Depression Scale in arthritis populations. Arthritis and Rheumatism 32: 991-997. Bradley LA (1985) Psychosocial aspects of arthritis. Bulletin of the Rheumatic Diseases 35: 1-12. Bradley LA (1989) Psychosocial factors and disease outcomes in rheumatoid arthritis: old problems, new solutions, and a future agenda. Arthritis and Rheumatism 32: 1611-1614. Burnam MA & Wells KB (1990) Use of a two-stage procedure to identify depression: the medical outcomes study. In Attkisson CC & Zich JM (eds) Depression in Primary Care: Screening and Detection, pp 98-116. London: Routledge. Callahan L, Kaplan MR & Pincus T (1991) The Beck Depression Inventory, Center for Epidemiological Studies Depression Scale (CES-D), and General Well-Being Schedule Depression Subscale in rheumatoid arthritis: criterion contamination of responses. Arthritis Care and Research 4: 3-11. Cassileth BR, Lusk EJ, Strouse TB et al (1984) Psychosocial status in chronic illness: a comparative analysis of six diagnostic groups. New England Journal of Medicine 311: 506-511. Creed F (1990) Psychological disorders in rheumatoid arthritis: a growing consensus? Annals of the Rheumatic Diseases 49: 808-812. Creed F, Murphy S & Jayson MV (1990) Measurement of psychiatric disorder in rheumatoid arthritis. Journal of Psychosomatic Research 34: 79-87. DeVellis BM & Blalock SJ (1992) Illness attributions and hopelessness depression: the role of hopelessness expectancy. Journal of Abnormal Psychology 101: 257-264. Endicott J & Spitzer RL (1978) A diagnostic interview: the schedule of Affective Disorders and Schizophrenia. Archives of General Psychiatry 35: 837-844.

256

B . M . DeVELLIS

Ferguson B & Tyrer P (1989) Rating instruments in psychiatric research. In Freeman C & Tyrer P (eds) Research Methods in Psychiatry, pp 148-175. UK: Royal College of Psychiatry. Goldberg DP, Cooper B, Eastwood MR, Kedward HB & Shepherd M (1970) A standardized psychiatric interview for use in community surveys. British Journal of Preventative and Social Medicine 24: 18-23. Hamilton M (1960) A rating scale for depression. Journal of Neurology, Neurosurgery and Psychiatry 23" 56-62. Hawley DJ & Wolfe F (1992) Depression is not more common in rheumatoid arthritis: a 10 year longitudinal study of 6,608 rheumatic disease patients. Arthritis Care and Research 5: $9. Hnatiuk SH & Duncan-Jones P (1990) Methodological issues in the study of personality and psychiatric state in rheumatoid arthritis. International Journal of Psychiatry in Medicine 20: 293-306. Johnson J, Weissman MM & Klerman GL (1992) Service utilization and social morbidity associated with depressive symptoms in the community. Journal of the American Medical Association 267: 1478-1483. Katon W & Sullivan MD (1990) Depression and chronic medical illness. Journal of Clinical Psychiatry 51(supplement): 3-14. Katz P & Yelin E (in press) Prevalence and correlates of depressive symptoms among persons with rheumatoid arthritis. Journal of Rheumatology. Klerman GL & Weissman MW (1992) The course, morbidity, and costs of depression. Archives of General Psychiatry 49: 831-834. Last JM (1983) A Dictionary ofEpidemiology, pp 49, 83. New York: Oxford University Press. Lerman CE (1987) Rheumatoid arthritis: psychological factors in the etiology, course, and treatment. Clinical Psychology Review 7: 413-425. Meenan RF, Gertman PM & Mason JH (1980) Measuring health status in arthritis: the Arthritis Impact Measurement Scales. Arthritis and Rheumatism 23: 146-152. Miller I, Bishop S, Norman W e t al (1985) The modified Hamilton Rating Scale for Depression: reliability and validity. Psychiatry Research 14: 131-142. Morrow KA, Parker JC & Russell JL (in press) Clinical issues in the management of depression in rheumatoid arthritis. Journal ofRheumatology. Murphy JM (1990) Depression screening instruments: history and issues. In Atkinson & Zich JM (eds) Depression in Primary Care: Screening and Detection, pp 65-83. London: Routledge. Murphy S, Creed F & Jayson MIV (1988) Psychiatric disorder and illness behaviour in rheumatoid arthritis. British Journal of Rheumatology 27: 357-363. Peck JR, Smith TW, Ward JR & Milano R (1989) Disability and depression in rheumatoid arthritis. Arthritis and Rheumatism 32: 1100-1106. Pincus T, Callahan LF, Bradley LA, Vaughn WK & Wolfe F (1986) Elevated MMPI scores for hypochondriasis, depression, and hysteria in patients with rheumatoid arthritis reflect disease rather than psychological status. Arthritis and Rheumatism 29: 1456-1466. Pope AM & Tarlov A R (eds) (1991) Disability in America: Toward a National Agenda for Prevention, p 40. Washington, DC: National Academy Press. Quirk ME & Young MH (1990) The impact of J R A on children, adolescents, and their families: current research and implications for future studies. Arthritis Care and Research 3: 36-43. Radloff LS (1977) The CES-D scale: a self-report depression scale for research in the general population. Applied Psychological Measurement 1: 385-401. Radloff LS & Locke BZ (1986) The community mental health assessment survey and the CES-D Scale. In Weissman M, Myers J & Ross C (eds) Community Surveys of Psychiatric Disorders. New Brunswick, N J: Rutgers University Press. Robins LN, Helzer JE, Croughan J & Ratcliff KS (1981) National Institute of Mental Health Diagnostic Interview Schedule: its history, characteristics, and validity. Archives of General Psychiatry 38: 381-389. Rodin G, Craven J & Littlefield C (1991) Depression in the Medically Ill: an Integrated Approach, pp 1-91. New York: Brunner/Mazel. Spitzer RL, Endicot J & Robins E (1978) Research diagnostic criteria: rationale and reliability. Archives of General Psychiatry 35: 773-782. Spitzer RL, Williams JBW, Gibbon M & First MB (1992) The Structured Clinical Interview for DSM-III-R (SCID) 1: History, rationale, and description. Archives of General Psychiatry 49: 624-629.

DEPRESSION IN RHEUMATOLOGICAL DISEASES

257

Stewart AL, Greenfield S, Hays RD et al (1989) Functional status and well-being of patients with chronic conditions: results from the Medical Outcomes Study. Journal of the American Medical Association 262: 907-913. Weissman MM, Leaf PJ & Tischler GL et al (1988) Affective disorders in five communities. Psychological Medicine 18: 141-153. Wells KB, Golding JM & Burnam MA (1988) Psychiatric disorder in a sample of the general population with and without chronic medical conditions. American Journal of Psychiatry 145: 976-981. Wells KB, Golding JM & Burnam MA (1989a) Affective, substance abuse, and anxiety disorders in persons with arthritis, diabetes, heart disease, high blood pressure, or chronic lung conditions. General Hospital Psychiatry 11: 320-327. Wells KB, Stewart A, Hays RD et al (1989b) The functioning and well-being of depressed patients: results from the Medical Outcomes Study. Journal of the American Medical Association 262: 914-919. Wing JK, Cooper JE & Satorius N (1974) The Measurement and Classification of Psychiatric Disorder. London: Cambridge University Press. Wolfe F (1990) Fibromyalgia. Rheumatic Disease Clinics of North America 16: 681-698. World Health Organisation (1977) Manual of the International Statistical Classification of Diseases, Injuries, and Causes of Death, 9th Revision. Geneva: WHO. Young LD (1992) Psychosocial factors in rheumatoid arthritis. Journal of Consulting and Clinical Psychology 60: 619-627.