Neurodevelopmental disorders among Spanish school-age children: prevalence and sociodemographic correlates.

BACKGROUND: Prevalence estimates of neurodevelopmental disorders (ND) are essential for treatment planning. However, epidemiological research has yielded highly variable rates across countries, including Spain. This study examined the prevalence and sociodemographic correlates of ND in a school sample of Spanish children and adolescents. METHODS: The Child Behaviour Checklist/Teacher's Report Form/Youth Self-Report and the Conners' Rating Scales were administered for screening purposes. Additionally, teachers provided information on reading and writing difficulties. Subjects who screened positive were interviewed for diagnostic confirmation according to the Diagnostic and Statistical Manual of Mental Disorders criteria. The final population comprised 6834 students aged 5-17. Multivariate analyses were performed to determine the influence of gender, age, educational stage, school type, socioeconomic status (SES), and ethnicity on the prevalence estimates. RESULTS: A total of 1249 (18.3%) subjects met criteria for at least one ND, although only 423 had already received a diagnosis. Specifically, the following prevalence rates were found: intellectual disabilities (ID), 0.63%; communication disorders, 1.05%; autism spectrum disorder (ASD), 0.70%; attention-deficit/hyperactivity disorder (ADHD), 9.92%; specific learning disorder (SLD), 10.0%; and motor disorders, 0.76%. Students of foreign origin and from low SES evidenced higher odds of having ID. Boys were more likely to display ASD or a motor disorder. Age, SES, and ethnicity were significant predictors for SLD, while communication disorders and ADHD were also associated with gender. CONCLUSIONS: The prevalence of ND among Spanish students is consistent with international studies. However, a substantial proportion had never been previously diagnosed, which emphasise the need for early detection and intervention programmes.

Strengths and Difficulties Questionnaire: Psychometric Properties and Normative Data for Spanish 5- to 17-Year-Olds.

The Strengths and Difficulties Questionnaire (SDQ) has been extensively used to measure common forms of psychopathology among children and adolescents. However, its psychometric properties vary across countries and several controversial issues warrant further investigation. This study aimed to evaluate whether the Spanish version of the SDQ is a reliable and valid tool for assessing emotional and behavioral problems in a sample of 6,775 students aged 5 to 17 years, as rated by parents, teachers, and youth. We examined the internal consistency of the questionnaire, its factor structure, and measurement invariance across child's gender and age. Criterion validity was tested against the Child Behavior Checklist (CBCL), Teacher's Report Form (TRF), and Youth Self-Report (YSR), and we measured the ability of the SDQ to identify children with specific psychiatric disorders. Finally, we provide, for the first time, Spanish normative data for children aged 5 to 10 and 11 to 17 years, according to gender and each informant. Our results revealed acceptable reliability estimates for all SDQ subscales. Confirmatory factor analysis supported the original five-factor model and full measurement invariance was found. Furthermore, SDQ scores showed a moderate to strong correlation with those on the equivalent CBCL/TRF/YSR scales, and were effective in discriminating individuals with and without clinical diagnoses.