Those with score of 5 or less were classified as good sleepers [18, 29]. The researcher had obtained permission to use the PSQI by translating the menuscript from English to Thai language. To ensure the PSQI’s validity, the backtranslation was also executed. The internal consistency reliability of the PSQI in this study yielding a Cronbach’s α = .0.77, was conducted in high school students, rather than samples from 10 selected schools, in Bangkok, under the supervision