were prominent themes for both staff and patients. Interpretation: The hospital’s response required clear communication, sensitivity to individual responses to stress, collaboration between disciplines, authoritative leadership and provision of relevant support. The emotional and behavioural reactions of patients and staff are understood to be a normal, adaptive response to stress in the face of an overwhelming event. CMAJ 2003;168(10):1245-51:xxx-xx CMAJ • MAY 13, 2003; 168 (10) 1245 © 2003 Canadian Medical Association or its licensors Robert Maunder, Jonathan Hunter, Leslie Vincent, Jocelyn Bennett, Nathalie Peladeau, Molyn Leszcz, Joel Sadavoy, Lieve M. Verhaeghe, Rosalie Steinberg, Tony Mazzulli may benefit others who are developing a comprehensive psychosocial response to SARS. Furthermore, this experience may be useful in planning a response to other infectious outbreaks, such as pandemic influenza.10 Methods Descriptions of the experience of patients with SARS and those without, the experience of health care workers and the institutional response were collected through unstructured interviews by the 2 principal authors (R.M., J.H.) with core team members and mental health care providers at Mount Sinai Hospital, Toronto. The core team members included the Vice-President of Nursing (L.V.), the Program Director of Nursing (J.B.), the Chair of the Medical Advisory Council (J.S.), the Director of Community Health Programs (R.S.), mental health professionals attending patients with SARS and patients without SARS (2 consultation–liaison psychiatrists [J.H., R.M.], a psychiatric clinician nurse specialist [N.P.] and a social worker [L.M.V.]) and a psychiatrist (M.L.) who met with health care workers individually to provide support at their request. Our observations were made for the period from Mar. 13, 2003, to Apr. 10, 2003, based on clinical observations of 19 patients with SARS and those without SARS who were also receiving care from the same mental health professionals (N.P., L.M.V., J.H., R.M.), observations by leaders and managers (L.V., J.B., R.S.) of staff, observations by mental health professionals (N.P., L.M.V., J.H., R.M., J.S., M.L.) of staff members who sought psychological support formally and informally, and first-hand observations by leaders (L.V., J.B., J.S.) of the administrative response. A microbiologist (T.M.) provided information about the cases, the disease and its treatment. We met in small groups and communicated by email to review and analyze these observations in order to determine the face validity of our observations by consensus in an iterative process between Apr. 3 and Apr. 13, 2003. The unexpected onset and rapid expansion of the SARS outbreak over its first 4 weeks, and the clinical responsibilities of the team, precluded systematic data collection. Psychological responses are condensed into narrative descriptions rather than being quantified. Results Description of cases The first patient with a case of SARS at Mount Sinai Hospital, Toronto, was admitted on Mar. 13, 2003. By April 10, 19 patients with probable and suspected SARS had been treated (Fig. 1). Of these, 11 were health care workers (5 nurses, 4 physicians, 2 others). Of the 11 health care workers, 9 worked at our hospital. One case of SARS was diagnosed at autopsy about 1 week after that patient’s transfer from our intensive care unit (ICU) to another hospital. This patient had been in our ICU for about 36 hours (Mar. 22–23). After about 14 hours in the ICU, clinical suspicion of SARS resulted in the use of isolation precautions. Unprotected exposure before the isolation precautions were instituted was the likely source of infection for 6 cases. Likely sources of infection for other cases were exposure to infected patients or staff in other health care settings in 6 cases, domestic exposure to a probable SARS case in 6 and exposure during transport of an infected patient in 1 case. Episodes of unprotected exposure of health care workers are documented in Table 1. As of April 10, there were no cases of secondary transmission to health care workers who were following isolation precautions. Fourteen patients were treated in the SARS isolation unit that the hospital set up on March 28, 2 were