Emergency Psychiatry in the General Hospital The emergency room is the interface between community and health care institution. Whether through outreach or in-hospital service, the psychiatrist in the general hospital must have specialized skill and knowledge to attend the increased numbers of mentally ill, substance abusers, homeless individuals, and those with greater acuity and comorbidity than previously known. This Special Section will address those overlapping aspects of psychiatric, medicine, neurology, psychopharmacology, and psychology of essential interest to the psychiatrist who provides emergency consultation and treatment to the general hospital population. Substance misuse among older patients in psychiatric emergency service Benjamin K.P. Woo, M.D. a,b, ⁎ , Weilu Chen a a Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA 90095, USA b Olive View-UCLA Medical Center, Sylmar, CA 91342, USA Received 27 May 2009; accepted 3 August 2009 Abstract Objective: To determine the prevalence of substance misuse among older patients presented to a psychiatric emergency service (PES) on involuntary bases. Method: At the time of initial presentation to the PES, all patients received a comprehensive assessment that included a urine toxicology screening. The screening consisted of six substances: barbiturate, benzodiazepine, cocaine, opiate, phencyclidine and amphetamine. Charts of elderly patients (aged 65 and above) with positive urine toxicology were reviewed to ensure that the results were not due to (1) home medications and (2) medications given in the PES. Results: During the 2-year study period (2006–2007), there were 5914 patients under the age of 65 and 104 patients aged 65 and above. Our findings indicated that 471 (8.0%) and 14 (13.4%) urine toxicology screens were not collected during the PES visits in younger and older patients, respectively (P=.04). The positive urine toxicology rate was 31.5% (1716/5443) and 26.7% (24/90) for younger and older patients, respectively (P=.33). Conclusions: Substance misuse in the older population presenting with psychiatric emergency is prevalent in the PES. Urine toxicology screens, as well as patient or collateral report of substance usages, should be obtained from this group of patients to ensure quality of care delivered at the PES. Published by Elsevier Inc. Keywords: Psychiatric emergency service; Substance; Geriatric 1. Introduction The number of elderly persons with psychiatric disorders is expected to reach 15 million by the year 2030 [1]. While substance abuse among older adults is on the rise, little is known about the epidemiology of substance use practices in the elderly [2,3]. In particular, there is a paucity of information on substance use disorders of geriatric patients in the psychiatric emergency service (PES). The PES serves as the gateway for elderly patients to receive mental health services [4]. Reasons for PES visits by elderly patients include psychiatric emergencies in the form of aggression, confusion, depression, homicidality, suicid- ality and substance abuse. The function of the PES is to conduct an evaluation, establish an initial diagnosis and provide emergency treatment and appropriate disposition [5]. Unrecognized substance use may lead to inaccurate psychi- atric diagnoses in the PES [6]. Thus, screening for substance use in elderly patients may allow for appropriate treatment and prognosis. Estimates based on the 2007 National Survey on Drug Use and Health indicate that the past year and lifetime history of illicit drug use for the elderly were 1.0% and 10.7%, respectively [7]. Holroyd and Duryee [2] found the prevalence of substance use disorder in a specialized geriatric psychiatry outpatient clinic to be 20%. Schlaerth et al. [8] studied 3417 patients over 50 years of age that presented to an emergency room in California and found that 107 patients had positive urine toxicology screens. Available online at www.sciencedirect.com General Hospital Psychiatry 32 (2010) 99 – 101 ⁎ Corresponding author. Tel.: +1 818 364 1555. E-mail address: bkpwoo@gmail.com (B.K.P. Woo). 0163-8343/$ – see front matter. Published by Elsevier Inc. doi:10.1016/j.genhosppsych.2009.08.002