At least five reports suggest that primary care practitioners underdiagnose and/or undertreat depressive conditions (Gullick and King, 1979; Johnson, 1974; Ketai, 1976; Magruder-Habib, Zung, Feussner, et al., 1989; Popkin and Callies, 1987). In fact, only one-third to one-half of patients with major depressive disorder are properly recognized by primary care and other practitioners. Only about one-third of patients with bipolar disorder are in treatment. The problem of underrecognition is important enough to warrant special attention.
Other psychiatric disorders are often accompanied by mood symptoms or formal mood syndromes. That is, patients may suffer concurrently from two psychiatric syndromes. In addition, substance abuse or withdrawal may cause mood symptoms/syndromes—so-called substance-induced mood disorders.
Depressive symptoms or full syndromes commonly accompany a variety of other general medical disorders. For example, diabetes, cancer, heart attacks, and stroke are often accompanied by depressive symptoms of sufficient duration and intensity to meet the criteria for specific mood syndromes. Recognized general medical conditions, such as necrologic, metabolic, oncologic, and other illnesses, can biologically cause mood symptoms or formal mood syndromes (i.e., organic or secondary mood disorders). In other cases, mood syndromes may be psychological reactions to the disability or prognosis associated with nonpsychiatric medical conditions. Some prescription medicines used to treat general medical conditions, such as antihypertensive drugs, may also precipitate or maintain depressive symptoms or syndromes, especially in persons with a personal or family history of mood disorders.
For these reasons, the Depression Guideline Panel has provided Clinical Practice Guideline: Depression in Primary Care to introduce practitioners to the key features of depressive conditions and, thus, to improve early diagnosis. This guideline, an abbreviated version of a far larger document, is divided into two volumes: this one, Volume 1. Detection and Diagnosis, and its companion, Volume 2. Treatment of Major Depression. The nearly 40 literature reviews conducted for these guidelines identified more than 3,500 relevant references, which are cited in the Guideline Report (roughly 1,200 pages). Only recent reviews and highly salient references are cited here.
The panel defined depression according to the current U.S. standard diagnostic system in the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised (DSM-III-R) (American Psychiatric Association, 1987). Given the need to complete this report in a timely fashion, the panel focused on major depressive disorder with some consideration of DNOS. The DSM-III-R system is closely aligned with and easily translated to the International Classification of Diseases, Ninth Edition (ICD-9) system of the World Health Organization (WHO). Both the DSM-III-R and the ICD-9 are undergoing revisions, which are to be completed by the end of 1993. In choosing to use the DSM-III-R, the panel acknowledges the availability of other clinical taxonomies pertinent to the diagnosis of depression in primary care practice and recognizes that the selection of a particular taxonomy can add bias to the guideline. The panel recognizes this limitation, but believes the DSM-III-R to be the best taxonomy available at this time.
The panel also recognizes that a variety of clinical conditions may be viewed as mood disorder “equivalents.” These include masked depression, chronic pain, chronic fatigue syndrome, somatization disorder, fibromyalgia, and others. The panel commissioned reviews of the literature on these conditions to provide a scientific basis for recognizing and differentiating these conditions from mood disorders.
Practitioners often confront clinical situations for which direct research data are limited, but for which indirectly relevant data are available. The translation of what is scientifically confirmed or suspected into what is clinically required or recommended requires training, professional judgment, and experience.
These guidelines are based on systematic literature reviews conducted by experts in diverse substantive areas relevant to depression, with special attention to the clinical issues most pertinent to the diagnosis and treatment of depression in primary care. To develop principles for diagnosis and treatment of mood syndromes in association with other illnesses, the panel also commissioned reviews of the literature on depression and selected general medical conditions. Where evidence is either lacking or incomplete, this is noted; in these cases, either no guideline has been derived or options are provided, based on logical inference, available data, and panel consensus. When the evidence is reasonably clear, though modest in amount, these findings are noted, and a tentative recommendation is offered. Thus, the guidelines that follow are coded according to the strength of the available evidence as interpreted by the panel:
This synopsis of diagnostic issues is not based on reviews of the evidence for or against the validity of specific diagnostic entities. (For such reviews, see DSM-IV Sourcebook [Frances and Widiger, in press].) Rather, the panel reviewed the epidemiology of major depressive disorder in community samples and primary care settings and the course, cooccurrence, and co-morbidity of depressive and other medical conditions. The panel also reviewed literature on the role of self-reports and clinician ratings as tools for detecting or differentially diagnosing depression. The role of laboratory tests in differential diagnosis of the medical causes of depression was illustrated by using the example of thyroid function testing.
This synopsis describes the various forms of depression; their course, epidemiology, and common clinical expression in different age groups; the co-occurrence of depressive symptoms or formal syndromes with other psychiatric or nonpsychiatric medical conditions; the role of medications in causing depression; and the role of clinical and laboratory procedures in the detection and differential diagnosis of depression.
The depression guidelines were drafted in four different formats: (1) the full Depression Guideline Report; (2) the Clinical Practice Guideline, which condenses pertinent information from the report into two volumes for easy use by practitioners; (3) the summary Quick Reference Guide for Clinicians; and (4) A Patient’s Guide. The literature reviews, drafts of the full Depression Guideline Report, and all four shorter versions were sent to 14 scientific reviewers, who critiqued them. The guidelines were revised and sent to the original 14 reviewers, plus 14 new scientific reviewers for further critique and subsequent revision.
Peer review was requested for both the diagnosis and treatment volumes, as well as for A Patient’s Guide and the Quick Reference Guide for Clinicians, from 73 professional organizations and 3 patient advocacy groups. In addition, independent family, general medical, and nurse practitioners reviewed these guidelines for ease of use, feasibility, and utility. These reviews provided the basis for final guideline revisions (Figure 1). Figure 1. Guideline development process
Additional revisions to these guidelines are anticipated, based on further comments from practitioners, new scientific evidence, studies of the impact of these guidelines on primary care practice, and new reviews to address areas not yet discussed. For example, the panel has not reviewed treatment of certain conditions, such as bipolar disorder; certain treatments, such as use of lithium alone; or certain patient groups, such as children and adolescents. These topics were deferred to subsequent years either because they are less common in primary care or because logistic constraints made deferral necessary. The panel invites correspondence front users to help in these future revisions.
Several limitations to the available scientific literature made the development of guidelines for primary care providers difficult:
Although several authors have questioned the generalizability of research findings from psychiatric to primary care settings, many difficulties encountered in primary care are also found in psychiatric settings. These include distinguishing depressions from underlying medical disorders, identifying medical disorders that present with depressive symptoms, treating mood disorders in patients with other general medical illnesses, and identifying and treating depressive psychological reactions to nonpsychiatric medical disorders.
The panel believes it essential to highlight the impact of current social and cultural forces, as well as current reimbursement policies, on timely diagnosis and treatment of depressive and other psychiatric conditions.
Social stigma contributes to:
Because of the current discrimination against persons with depressive and other psychiatric conditions, appropriate diagnosis and treatment may carry a far greater personal cost for patients with depression than for those with other medical conditions. In some cases, acknowledgment of diagnosis and treatment of depression can actually worsen an individual’s social, occupational, and economic status. The ultimate long-term consequences of this stigma must be addressed to ensure accurate, early diagnosis and effective, early treatment.
The implementation of these guidelines may require one or more of the following:
On the other hand, use of these guidelines may reduce overall medical costs, since patients with clinical depression may be identified and treated earlier in the course of the illness, thus reducing the need for multiple physician visits for various somatic symptoms of depression (e.g., tension headaches, abdominal pain, joint pain, insomnia) and the need for eventual, more complex and expensive treatments for more chronic depressions. Indirect cost savings, such as fewer days lost from work, less disability, and less pain and suffering, are additional benefits of effective treatment.