Background: Disasters of the magnitude of September 11, 2001 have a serious public health impact. By dominating media broadcasts, this effect is not limited to the site of the disaster. We tested the hypothesis whether such extraordinary burden results in an increase of psychiatric inpatient treatment. As such we analysed all psychiatric inpatient admissions in the Canton of Zurich/Switzerland. To test the influence of proximity to a disaster, we additionally analysed the impact of a local amok run on September 27, 2001.
Methods: Psychiatric inpatient admissions in the Canton of Zurich from September 2000 to September 2002 were analysed based on the data of the psychiatric case register. ARIMA modelling was employed to describe time-series of admissions per week over the 2-year period and to identify the impact of the incidents of 9/11 and 9/27, 2001.
Results: Mean numbers of weekly admissions were comparable in a time span of one month before and one month after the two incidents, thus, no significant changes were detected by the ARIMA modelling.
Conclusion: Against widespread beliefs, for patients with severe mental disorders requiring hospitalisation illness factors seem to play a more relevant role for decompensation than external psychosocial factors such as the described incidents.