Psychiatric Comorbidity: Occurrence and Treatment
Miller, Norman S., Alcohol Health & Research World
Alcoholics with psychiatric disorders often fail to receive adequate treatment. Integrated treatment programs show promise for helping these patients.
Comorbidity is the occurrence of two or more illnesses in the same person. The term "psychiatric comorbidity," as used in this article, refers to the occurrence in the same person of at least one mental disorder and one addictive disorder. For example, a person suffering from schizophrenia may be addicted to alcohol and perhaps to other drugs as well.(1)
Psychiatric comorbidity presents problems for clinicians and patients alike. Comorbid disorders are poorly understood and frequently misdiagnosed, and their treatment is problematic. Alcoholics with psychiatric disorders often fall through the cracks in the health care system, failing to receive treatment for one or the other of their disorders (Minkoff 1989; Ries 1993). Nevertheless, prospects for effective treatment are improving with the increasing integration of psychiatric and addiction treatment perspectives. This article explores some problems in recognizing comorbidity and evaluates current treatment models.
EVALUATING PSYCHIATRIC COMORBIDITY
Epidemiologic studies attempting to measure prevalence rates for psychiatric comorbidity have produced widely varying results, as discussed below. To evaluate and interpret these results, the following factors must be considered: population selection, the perspective of the researcher or clinician, definitions and diagnostic criteria, and followup.
Study subjects may be drawn from the general population or from patients in treatment (Lyons and McGovern 1989; Pepper et al. 1981; Miller and Fine 1993). Higher rates of comorbidity generally are found in patient populations than among the general population. This probably is because persons with multiple disorders are among the most likely to seek treatment (Pepper et al. 1981). Estimates of the type and prevalence of comorbidity in a patient population may reflect the primary type of treatment those patients are receiving. For example, a general psychiatric hospital would contain more chronically mentally ill (CMI) patients (e.g., schizophrenics and manic-depressives) than would be found ordinarily at an alcoholism treatment center. Moreover, prevalence rates for comorbidity (i.e., chronic mental illness together with alcohol and other drug [AOD] disorders) are higher for inpatient than for outpatient treatment settings and greater for public (i.e., community) than for private settings.
Perspective of the Researcher or Clinician
The clinician's or researcher's perspective is a key factor in assessing prevalence rates. Psychiatrists tend to emphasize psychiatric explanations for alcoholism, whereas alcoholism treatment professionals emphasize alcoholism as an independent disorder (Schuckit 1985). These biases affect the way populations are selected and defined and how disorders are diagnosed.
Definitions and Diagnostic Criteria
Overestimates of psychiatric comorbidity may result from failure to distinguish between symptoms and disorders. For example, alcoholics undergoing prolonged periods of alternating intoxication and withdrawal frequently manifest symptoms such as hallucinations, paranoid delusions, and thought disturbances. These symptoms occur in disorders such as schizophrenia and mania but also can be induced by alcohol consumption in the absence of any psychiatric disorder. Similarly, alcohol consumption can produce symptoms of anxiety and depression in patients who do not have independent anxiety or depressive disorders. Thus, the frequency of psychiatric symptoms in alcoholics is much higher than the occurrence of true psychiatric disorders.
Confusion of symptoms and disorders can be avoided by the careful use of appropriate diagnostic criteria. The Diagnostic and Statistical Manual of Mental Disorders. Fourth Edition (DSM-IV) is a standard guide to defining and diagnosing mental and addictive disorders. …