Psychological epidemic in Hong Kong. II. Psychological and physiological characteristics of children who were affected.

A double blind retrospective study was carried out on a sample of children who were affected in a mysterious gas poisoning epidemic together with controls drawn from the same school. The dependent measures employed were the Junior Eysenck Personality Questionnaire (JEPQ), a Hypnotic Susceptibility Scale (HSC), Heart Rate (HR) and Skin Potential Response (SPR). A vigilance task was administered during assessment of the latter two variables. The affected children had significantly higher HR together with a marginal increase in SPR. It is proposed that constitutional factors play an important role in determining whether an individual is affected in such an epidemic.