Pilot study for the Quebec Child Mental Health survey: Part I. Measurement of prevalence estimates among six to 14 year olds.

A pilot study for a Quebec Child Mental Health Survey was completed in 1990 with 139 children aged six to 14 years from the general population. Six month prevalence estimates for seven disorders were established using DSM-III-R criteria alone and in combination with an impairment index related to the diagnoses. Prevalence estimates were studied separately for parents and children. Each age group (six to 11, 12 to 14) was also studied separately. The impairment index, working as a severity scale, lowered prevalence estimates and allowed identification of impairing and non impairing diagnoses. Little overlap was found between informants.