The standardization of Achenbach's Youth Self-Report in Greece in a national sample of high school students.

Achenbach's Youth Self Report (YSR) questionnaire is accepted worldwide for the assessment of adolescent competencies and behaviour problems. As with any similar instrument, it is liable to cultural influences, hence requires standardization for the culture in which it is to be used. This study reports on the standardization of the YSR in Greece, in a national school-based sample of 1456 high school students, 11-18 years of age. Responses at the item level seem to follow the culturally expected gender behaviour. Behaviour problem scale scores were not affected by degree of urbanization, reflecting a high degree of cultural homogeneity between urban and rural areas in Greece. Sex effects were important, with girls showing a greater tendency towards Internalizing and boys towards Externalizing Problems. Age effects were also statistically significant (older adolescents showing more problems, especially of the delinquent type), but numerically small. There was considerable correlation between Internalizing and Externalizing problems, with an odds ratio of 6.9 (95% confidence interval, 4.6-10.4) for exceeding both cut-offs. The analysis showed that Greek adolescents obtained significantly higher mean scores than their American counterparts on all scales. Cut-off points based on the 90th and 98th percentile developed from this sample are presented for the competencies and the problem scales.