The study proposal was submitted, reviewed, and officially authorized by the ethic committee of Department of Mental Health, Ministry of Public Health before conducting the survey (Reference number 21/2551). Data collection consisted of face-to-face interviews carried out in a temporary housing structure, a home, or a school. The children were interviewed by mental health professionals from DMH. Children in need of mental health support were referred to mental health services available both in temporary shelters and in community areas. First assessment was conducted from February 15th to February 22nd, 2005 in Phang Nga, Phuket and Krabi provinces. According to high prevalence rate of mental health problems among affected people in Phang Nga in the first assessment, the second assessment was conducted in the same population only in Phang Nga province from September 7th to 12th, 2005 (9 months after tsunami). The third assessment was conducted from February 11th and 18th, 2008 (3 years after tsunami) by DMH. All parents or guardians and children in this study were asked for verbal informed consent. Children who lost their homes or home damaged and lived in the temporary shelters were defined as displaced children.