Increased incidence of stress-associated illnesses among elderly after Typhoon Morakot

Typhoon Morakot in August 2009 caused significant damages and health and socio-economic impacts in Taiwan. Therefore, we evaluated the mental health status of adult and patients who lived in the affected area after the disaster.

An observational, prospective population-based study was conducted. Adults living in the affected area were selected as the affected population in the National Health Insurance Database from January 2008 to December 2011. Prevalence and incidence of stress-associated illnesses, such as insomnia, anxiety, depressive, adjustment and mood disorders, post-traumatic stress disorder (PTSD) in the psychiatry department were analysed after the disaster.

A total of 897,689 adult patients were studied. Of the affected population without pre-existing chronic mental health illness, the monthly visits for stress-associated illnesses, such as insomnia, anxiety, depressive disorders and PTSD increased about twice after the disaster in elderly and non-elderly groups. Comparing to the non-elderly group, the elderly group has more increased in the incidence of insomnia (356% vs. 318% increase) and depressive disorders (308% vs. 245%) but was affected to a lesser extent increase in the anxiety (269% vs. 307%), PTSD, episodic mood disorders (82% vs. 158%), and adjustment reaction (160% vs. 202%).

The mental health statuses of patients who experienced a major natural disaster deteriorated in the elderly population after the disaster. However, we still need pay more attentions on the elderly of the affected population to decrease the risk for insomnia and depressive disorders after the disaster.