DETECTION AND DIAGNOSIS OF PSYCHIATRIC DISORDERS IN PRIMARY MEDICAL CARE SETTINGS

The 1990s saw significant advances in the diagnosis and management of psychiatric disorders, including a better understanding of the presentation and treatment of these illnesses in general medical care settings. This article assists general internists and family practitioners in increasing their index of suspicion for psychiatric disorders and presents simple, effective screening tools that can be incorporated into everyday practice along with methods of finalizing psychiatric diagnoses in an efficient manner. The impetus behind greater attention to psychiatric illnesses in primary medical settings is fourfold: (1) Most patients with psychiatric disorders are seen in primary care settings. (2) Patients with psychiatric illnesses use significantly more general medical resources and experience greater morbidity and functional impairment than their counterparts without psychiatric diagnoses. (3) Research has translated the seemingly arcane psychiatric nomenclature into practical tools designed specifically for general medical practice. (4) In the 1990s, numerous psychotropic medications were introduced that can be used safely and effectively in primary care. Data from a large, multicenter epidemiologic study of psychiatric disorders in the community (the Epidemiological Catchment Area studies) and subsequent work on service utilization by patients with psychiatric illnesses have shown repeatedly that primary care practitioners provide psychiatric treatment to more patients than any other group of health care professionals. 43,60 Patients with psychiatric illnesses may be seen more frequently than others with similar medical illnesses but no psychiatric diagnosis. In a study of more than 12,000 patients identified as high users of medical services in three health maintenance organizations (HMOs), 54 patients with active or partially remitted major depression used significantly more hospital days per 1000 and made significantly more medical office visits than patients without depression, even though the prevalence of well-characterized medical conditions was the same in both groups (41.5%). Another investigation found that individuals with panic disorder visited their primary care practitioner at three times the rate of other patients. 69 The economic burden of psychiatric illnesses in terms of lost productivity and functional impairment is at least as great as that caused by heart disease, diabetes, hypertension, and back problems. 21 Psychiatric disorders may complicate the course of coexisting medical illnesses. 23,35,74 Depression has been identified as an independent risk factor for sudden cardiac death in patients who have suffered a myocardial infarction and may increase the risk of a first ischemic event. 23,48 Anxiety disorders may complicate cardiac, 35 pulmonary, 64 and vestibular disorders, 67 possibly overshadowing the symptoms of the medical condition itself. Alcohol or other substance dependence may be the cause of unexplained dyspepsia, insomnia, impotence, and repeated orthopedic injuries as well as more severe illnesses, such as pancreatitis, gastrointestinal bleeding, peripheral neuropathies, liver disease, head trauma, and seizures. 71 Despite their prevalence, morbidity, and cost, psychiatric disorders continue to be underdiagnosed and treated incompletely in primary care settings. It is estimated that depressive disorders may not be recognized in one third to one half of patients with these conditions. 28,72 Several factors contribute to this situation. The strong stigma still associated with psychiatric disorders causes patients to be reluctant to share their emotional concerns with their physicians. Patients may focus instead on the physical aspects of their disorders and attribute their symptoms to medical problems. Another factor is the manner in which physicians perceive psychiatric symptoms. Anxiety and depression are a natural part of life, and most individuals experience these emotions more intensely during stressful life circumstances. It is not normal, however, to have functional impairments related to mood, anxiety, or cognitive symptoms or substance use. The physician needs to evaluate the duration, intensity, persistence, and disability caused by these psychologic symptoms and to examine their associated physical complaints to differentiate normal psychologic responses from psychiatric disorders. A final source of difficulty is the psychiatric classification system itself. There is evidence that primary care physicians do not use the standard diagnostic schema embodied in the three editions of the Diagnostic and Statistical Manual of Mental Disorders published by the American Psychiatric Association since 1980. 19 The main reason is that nonpsychiatric physicians find the schema cumbersome to use and instead rely on their own definitions of psychiatric illnesses or other diagnostic systems that they learned in their medical education. Since 1980, the psychiatric nomenclature has been refined through extensive fieldwork on the structure and classification of psychiatric illnesses, leading to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) in 1994. 4 Research in general medical care settings produced a primary care (DSM-IV-PC) version of this manual. 5 The DSM-IV-PC has diagnostic algorithms to evaluate eight categories of psychiatric disorders that are common in general medicine—depression, anxiety, cognitive abnormalities, substance use, unexplained physical symptoms, sleep and sexual disorders, weight and eating disorders, and psychosis. The Primary Care Evaluation of Mental Disorders (PRIME-MD), 66 a psychiatric screening instrument designed for primary care settings, also was published in 1994. It contains 26 yes/no questions about symptoms that patients may have experienced during the past month. In trials of the PRIME-MD, primary care physicians completed the instrument in an average of 8 minutes, 24 seconds. 66 This is a relatively short period of time but not short enough to permit the entire PRIME-MD to be used routinely. A more recent study introduced a streamlined patient self-report version of the PRIME-MD called the Patient Health Questionnaire (PHQ), which reduced physician time to less than 3 minutes. 65 The PHQ is 3 pages long and has questions covering the five most common groups of psychiatric illnesses in primary care—depressive, anxiety, alcohol, somatoform, and eating disorders. Its five sections can be used together or separately to target specific illnesses. Other investigations identified a few screening questions that can detect patients with depression rapidly in a busy clinical practice. 13,73 Several short, patient self-report measures now are available for specific problems, such as depression in the elderly 3 and alcohol and drug abuse. 24 This article describes the presentation of depressive, anxiety, cognitive, and substance use disorders in general medical care settings, highlighting the best available methods for detecting and diagnosing these conditions efficiently. Specific treatments are not discussed in any detail except to state that therapies now available give the primary care practitioner the tools to treat most common psychiatric disorders as readily as many other medical conditions.