Individual child factors affecting the diagnosis of attention deficit hyperactivity disorder (ADHD) in children and adolescents: a systematic review.

Attention deficit hyperactivity disorder (ADHD) is a prevalent condition characterised by patterns of inattention, hyperactivity, and impulsivity. This systematic literature review aims to identify the child clinical and sociodemographic factors related to the detection and diagnosis of ADHD in children and adolescents, given concerns about delays or failures in identifying ADHD as well as over-diagnosis, hindering appropriate and timely support for children and families. Through electronic and manual searches of peer-reviewed and grey literature, 5852 articles were identified and subjected to two stages of screening by independent reviewers. Due to the heterogeneity in study methods, a narrative approach was used to summarise study findings. Forty-one studies meeting eligibility criteria revealed sixteen child-related factors influencing the ADHD diagnostic process. These factors include ADHD subtype, ADHD symptom severity, comorbid mental disorders, behavior problems, internalizing symptoms, functional impairment, social and cognitive functioning, physical health, gender, age, relative age, race/ethnicity, socio-economic status, insurance coverage, residence urbanicity, and family structure. While the impact of many of these factors on ADHD diagnosis was inconsistent due to the substantial diversity in study designs and context, certain patterns emerged. Meeting the criteria for the inattentive subtype, lower functional impairment, female gender, Black or Latinx ethnicity, and being relatively young for their grade were consistently found to be associated with a delayed or absent ADHD diagnosis. Further research is needed to explore the intricate relationships between these child-level variables and their implications for ADHD recognition, referral, and evaluation, especially outside the USA.