Psychometric properties of the Conners-3 and Conners Early Childhood Indexes in a Spanish school population

Ba#ckground/Obje#ctive: To examine the psychometric properties of the Conners 3 ADHD Index (Conners 3 AI) and the Conners Early Children Global Index (Conners ECGI) parents’ form (PF) and teachers’ form (TF) in Spanish schoolers. Method: Two-phase cross-sectional study. In the first phase, information was gathered from teachers (n = 1,796) and parents (n = 882) of 4-5 and 10-11 year-old children. In the second phase (n = 196), children at risk of ADHD and controls were individually assessed. Results: The results confirmed the two-factor structure of the Conners 3 ADHD Index, which contains hyperactive-impulsive and inattentive symptoms, and the two-factor structure of the Conners ECGI PF, consisting of emotional lability and restless-impulsive symptoms. In contrast with the original version, the Conners ECGI TF presented an additional inattentive factor. Moderate-to-high rates of evidence of convergent validity with Child Behavior Checklist and Kiddie-Schedule for Affective Disorders & Schizophrenia, and evidence of external validity (academic achievement) were found. Scores were significantly higher in boys than in girls, for both indexes. Raw scores corresponding to clinical T-scores were higher than the original version. Conclusions: The Conners indexes may be considered reliable and valid instruments for detecting ADHD symptoms in Spanish populations.