Screening laboratory evaluation in psychiatric patients: a review.

Routine laboratory screening of psychiatric patients is a common clinical practice. Several studies have demonstrated the limited utility and higher cost of ambulatory and preadmission screening in the evaluation of general medical patients. The data concerning the use of such screening profiles in psychiatric patients are reviewed. Widespread use of extensive screening batteries, consisting of complete blood cell count (CBC), complete blood chemistry analysis, erythrocyte sedimentation rate (ESR), urinalysis, B12, folate, electroencephalogram (EEG), electrocardiogram (EKG), and chest x-ray film, is not indicated in the majority of psychiatric patients. Such investigations result in many abnormal findings, most of which are clinically insignificant and do not affect patient management and outcome. Most abnormal results can be predicted by information obtained from a careful history, review of systems, and physical examination. Certain populations appear to benefit from more extensive evaluation, including those older than 65 years of age or of low socioeconomic status, state hospital patients, patients with drug and alcohol histories, and patients with evidence of disorientation, self neglect, or organic mental disorders. The few tests that have merit as broader screening tests in asymptomatic patients include serum glucose, blood urea nitrogen (BUN), creatinine, and urinalysis. Patients on psychotropic medications should be monitored for side effects of that particular therapy. Further prospective data are needed to develop cost-efficient, population-specific diagnostic strategies.