Risk factors for spirit possession among school girls in southern Thailand

In September 1993, at a school in the south of Thailand, an outbreak of spirit possession suddenly afflicted 32 girls aged 9-14 years. A case-control study was done to investigate factors that predispose a child to spirit possession. Psychiatric evaluation was done on 32 cases and 34 matched controls. Parents were interviewed regarding the child's psychosocial history. Results of the study were as follows. Children with spirit possession were first-born and came from small families with 1-3 children. Compared with the controls their family life was characterized by more psychosocial stressors and there were significantly higher rates of psychiatric disorders, anxious and fearful character traits, histrionic character traits and history of recurrent trance states. The history of traumatic experiences and exposure to spirit possession ceremonies were more frequent in spirit-possessed children than in the control group but the difference was not significant. This study showed that being first-born from a small family, individual vulnerability especially psychiatric disorders, problematic character traits and dissociative tendency were significant risk factors in the development of possession states in children.