A series of papers from our longitudinal study of 3- to 6-year-old children have examined the predictive validity of early symptoms of ADHD, ODD, and CD. We have demonstrated that children with ADHD can be identified as early as age 3 with reasonable accuracy. We found that both diagnostic interviews as well as tests of neuropsychological functioning in 3- and 4-year-old children were predictive of later ADHD. Moreover, we have examined how different types of ADHD symptoms vary in their developmental trajectories across the preschool years, and have identified which symptoms may be more or less useful in distinguishing in children with and without ADHD. Our work has also demonstrated that other co-occurring disorders including conduct disorder and oppositional defiant disorder also exhibit substantial stability beginning at age 3. Moreover, we have shown that the preschool years are a critical time for the development of comorbid ODD among children with ADHD.
Rolon-Arroyo B, Arnold DH, Harvey EA. The predictive utility of conduct disorder symptoms in preschool children: a 3-year follow-up study. Child Psychiatry Hum Dev. 2014 Jun;45(3):329-37. PubMed PMID: 23979222; PubMed Central PMCID: PMC4707669.
Harvey EA, Youngwirth SD, Thakar DA, Errazuriz PA. Predicting attention-deficit/hyperactivity disorder and oppositional defiant disorder from preschool diagnostic assessments. J Consult Clin Psychol. 2009 Apr;77(2):349-54. PubMed PMID: 19309194; PubMed Central PMCID: PMC4655077.
Harvey EA, Friedman-Weieneth JL, Goldstein LH, Sherman AH. Examining subtypes of behavior problems among 3-year-old children, Part I: investigating validity of subtypes and biological risk-factors. J Abnorm Child Psychol. 2007 Feb;35(1):97-110. PubMed PMID: 17165141.
Harvey EA, Breaux RP, Lugo-Candelas CI. Early development of comorbidity between symptoms of attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD). J Abnorm Psychol. 2016 Feb;125(2):154-67. PubMed PMID: 26854502; PubMed Central PMCID: PMC4747057.
Harvey, E., Lugo-Candelas, C., & Breaux, R. (2015). Longitudinal changes in individual symptoms across the preschool years in children with ADHD. Journal of Clinical Child & Adolescent Psychology, 44, 580-594.