Parent-reported Early Atypical Development and Age of Diagnosis for Children with Co-occurring Autism and ADHD.

This study looked at 288 New Zealand families with children diagnosed with autism, ADHD, or both. When children have both conditions, they tend to get their ADHD diagnosis sooner but their autism diagnosis later. Parents noticed fewer early language and social concerns in children with both conditions, and these families waited longer and saw more specialists before getting an autism diagnosis.

This New Zealand survey of 288 parents examined diagnostic pathways for children with autism, ADHD, or both conditions. Children with co-occurring autism and ADHD showed distinct patterns: they received ADHD diagnoses earlier but autism diagnoses later compared to children with autism alone. Parents reported less pronounced early language and social difficulties in the co-occurring group, which may contribute to diagnostic delays. These children experienced longer wait times and required consultation with more specialist types before receiving their autism diagnosis, suggesting the presence of ADHD may complicate autism recognition and diagnosis.

Clinicians should maintain vigilance for autism in children already diagnosed with ADHD, especially when early developmental concerns were less pronounced. Diagnostic protocols may need refinement to reduce delays in identifying co-occurring conditions and minimize families' need to consult multiple specialists.

Single-country survey design limits generalizability. Parent-reported data may be subject to recall bias. No comparison of diagnostic accuracy or long-term outcomes. Sample characteristics and recruitment methods not fully described in abstract.

Autism and attention-deficit/hyperactivity disorder (ADHD) often co-occur. This survey of 288 New Zealand parents of children diagnosed with autism (n = 111), ADHD (n = 93), or both conditions (n = 84), examined the relations between age of diagnosis and early atypical development, the age specialist consultation was needed and types of specialists seen. Co-occurring autism and ADHD was associated with an earlier ADHD diagnosis and a later autism diagnosis. Parents of children with both diagnoses reported less atypical development in language and social behaviours compared to parents of children of autism, and this co-occurring group also experienced longer wait times to diagnosis, and saw more types of specialists prior to a diagnosis, than those with autism.