School teachers were among those most affected by post-traumatic stress disorder following the Christchurch earthquakes, University of Otago research has found.
The study published in Disaster Prevention and Management, An International Journal, involved a survey of 226 people - including 140 from Christchurch and 86 from Hamilton - affected by the 2010 and 2011 quakes.
It found most people suffering PTSD were those not considered traditional "first responders" to an emergency, lead researcher associate professor David McBride says.
Instead, they were more likely to be female, a teacher or someone who had experienced more than 11 so-called critical incidents, such as being injured or watching buildings collapse, during the earthquake.
Their distress typically lasted 12 months following the quakes.
Mr McBride said the finding of how common PTSD symptoms were among teachers suggested they needed support or training ahead of natural disasters.
The research findings now also had been passed on to the teachers unions, NZEI Te Riu Roa and the New Zealand Post Primary Teachers' Association.
"We are working with them to help their understanding, so we can apply the findings to future circumstances," he said.
Undertaken to identify what factors may have caused PTSD symptoms among frontline workers, the study also sought to identify vulnerable groups of people and how they could be helped ahead of time.
Among those included in the study's survey were utility, construction and demolition workers, Maori wardens, Red Cross workers, school teachers and non-government organisation staff.
These "non-traditional responders have leadership and management roles in crisis, both during the event and in the much longer recovery phase", the researchers said.
Mr McBride said past research had shown that school principals and teachers, in particular, played important roles in supporting the emotional recovery of students and families after disasters.
He said the University of Otago study backed this up with "teachers consistently (having) high scores for emotional exhaustion, anxiety and social dysfunction" after the Christchurch quakes.