Severity of pre-existing psychiatric illness and response to the Great East Japan Earthquake.

Reports have described how psychiatric patients respond to disasters. However, previous reports on the response depending on diagnostic categories have provided no clear consensus. Here we analyzed response to the Great East Japan Earthquake of March 11, 2011, among psychiatric patients in light of severity of pre-existing psychiatric illness. We studied psychiatric change among a population of psychiatric outpatients in Tochigi prefecture, located ~160 km (~100 miles) southeast of the Fukushima nuclear power plant, in an area that suffered moderate damage from the earthquake and radiation. A total of 294 psychiatric outpatients was assessed using the Global Assessment of Functioning (GAF-F). A change of ≥10 points in the GAF-F score was counted as a change in symptoms. The data were stratified by disease category, gender, and GAF-F score and analyzed using the Fisher's exact test. In the 2 months after the earthquake, 5.4% of patients showed evidence of a change in symptoms, with 4.1% worsening and 1.4% improving. Compared with patients having a GAF-F score ≤50, significantly more patients with a score >50 showed evidence of worsening symptoms. No significant difference was found with respect to gender or diagnostic category for patients with worsened or improved symptoms. Our findings reveal that a relatively small percent of patients with pre-existing psychiatric diseases showed evidence of a change in symptoms and that patients with mild-to-moderate psychiatric illness are potentially vulnerable to the impacts of a natural disaster.