{"doi":"10.1111/jcpp.14050","title":"Behavioral characteristics of toddlers later identified with an autism diagnosis, ADHD symptoms, or combined autism and ADHD symptoms","abstract":"BACKGROUND: Autism commonly co-occurs with attention-deficit/hyperactivity disorder (ADHD), but less is known regarding how ADHD symptoms impact the early presentation of autism. This study examined early behavioral characteristics of a community sample of toddlers later identified with autism diagnosis, ADHD symptoms, combined autism and ADHD symptoms, or neither condition. METHODS: Participants were 506 toddlers who were part of a longitudinal study of children's behavioral development. Parents completed questionnaires about their children's behavior at two time points. Four groups were identified based on study measures or medical record: autism diagnosis (n = 45), elevated ADHD symptoms (n = 70), autism and ADHD symptoms (n = 30), or neurotypical development (n = 361). Relationships between early parent report of autism- and ADHD-related behaviors, social-emotional and behavioral functioning, and caregiver experience and subsequent group designation were evaluated with adjusted linear regression models controlling for sex. RESULTS: Significant group differences were found in measures of autism-related behaviors, ADHD-related behaviors, externalizing and internalizing behaviors, and parent support needs (p < .0001). Pairwise comparisons indicated toddlers later identified with combined autism diagnosis and ADHD symptoms had higher levels of autism-related behaviors, externalizing and internalizing behaviors, and autism-related parent support needs compared to the other groups. Toddlers with subsequent elevated ADHD symptoms or combined autism diagnosis and ADHD symptoms exhibited similar levels of ADHD-related behaviors, while both groups displayed more ADHD-related behaviors than toddlers subsequently identified with autism or those with neither condition. CONCLUSIONS: In this community sample, toddlers for whom combined autism diagnosis and ADHD symptoms were subsequently identified showed a distinct presentation characterized by higher early autism-related behaviors, broader behavioral concerns, and higher parent support needs. Presence of ADHD symptoms (alone or in combination with autism) was associated with higher parent-reported ADHD-related behaviors during toddlerhood. Results indicate that ADHD-related behaviors are manifest by toddlerhood, supporting screening for both autism and ADHD during early childhood.","journal":"Journal of Child Psychology and Psychiatry","year":2024,"id":458302,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":5,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.897,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":379019,"name":"Reginald Lerebours","orcid":"0000-0003-2884-3168","position":1,"is_corresponding":false},{"id":1073645,"name":"Rachel Aiello","orcid":"0000-0002-5739-6304","position":2,"is_corresponding":false},{"id":366001,"name":"Kimberly L. H. Carpenter","orcid":"0000-0002-3838-798X","position":3,"is_corresponding":false},{"id":331683,"name":"Scott N. Compton","orcid":"0000-0003-2887-9582","position":4,"is_corresponding":false},{"id":594682,"name":"Lauren Franz","orcid":"0000-0003-4434-7500","position":5,"is_corresponding":false},{"id":363875,"name":"Scott H. Kollins","orcid":"0000-0001-6847-6935","position":6,"is_corresponding":false},{"id":263478,"name":"Maura Sabatos‐DeVito","orcid":"0000-0001-9882-4865","position":7,"is_corresponding":false},{"id":285120,"name":"Marina Spanos","orcid":"0000-0002-4601-8498","position":8,"is_corresponding":false},{"id":40233,"name":"Géraldine Dawson","orcid":"0000-0003-1410-2764","position":9,"is_corresponding":false},{"id":1019506,"name":"Naomi Davis","orcid":"0000-0003-0858-7152","position":0,"is_corresponding":true}],"reference_count":52,"raw_metadata":null,"created_at":"2026-07-19T02:03:46.117860Z","pmid":"39227035","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}