The Comorbidity of ADHD and Autism Spectrum Disorders (ASDs) in Community Preschoolers

Abstract

Symptoms of inattention and hyperactivity, features of attention-deficit/hyperactivity disorder (ADHD), have been frequently documented in children with autism spectrum disorders (ASDs) and often co-occur. Evidence indicates that 20-50% of children with ADHD meet criteria for ASD, and 30-80% of ASD children meet criteria for ADHD. According to the DSM-IV, the essential features of Autistic Disorder (AD) are "the presence of markedly abnormal or impaired development in social interaction and communication and a markedly restricted repertoire of activity and interests". Differential diagnosis of "Pervasive Developmental Disorder" (PDD: Autistic Disorder, Rett's Disorder, Childhood Disintegrative Disorder, Asperger's Disorder) and "Pervasive Developmental Disorder-Not Otherwise Specified"(PDD-NOS) is often difficult in the preschool child. This is particularly true when assessing verbal and nonverbal communication since both expressive and cognitive language are not yet established and there are many differences in their acquisition period among these children (before the age of three). As a result, many of these children are diagnosed with PDD-NOS not meeting the criteria for a specific type of PDD; this category includes "atypical autism" presentations that do not meet the criteria for AD. As a result, the concept of PDD-NOS has become a mixed bag. Often, diagnosis cannot be established before age three, delaying therapeutic interventions. Moreover, differential diagnosis between ADHD and PDD-NOS can be especially difficult, mainly in infant and young children. However, and following the recommendations of the DSM-IV, the ASDs diagnosis has been included among the exclusion criteria for the ADHD. Such exclusion has generated considerable controversy regarding the necessity and benefits of maintaining these separations. At present, a new edition of the DSM has been published: DSM-5® (Fifth Edition, 2013). Among the advantages that this new manual provides are: i) further categorization of the persons affected and ii) the possibility of diagnosis before the age of three. The DSM-5 takes into account that limitations in language are not specific to autism. The new diagnostic category "Social Communication Disorder" appears separate from ASD, which does not seek to create a new subcategory.

Delayed autism spectrum disorder recognition in children and adolescents previously diagnosed with attention-deficit/hyperactivity disorder

“…Previous research has also revealed that approximately half of children with a late diagnosis of autism initially receive additional developmental diagnoses (Jónsdóttir et al, 2011), in line with our current findings. On one hand, both conditions often encompass deficits in communication and attention, as well as varying degrees of impulsivity, restlessness, or hyperactivity (Carrascosa-Romero and De La Vega, 2015). Children with a diagnosis of ADHD have shown elevated ratings of core ASD traits that could not be accounted for by ADHD symptoms or additional behavioral problems, supporting the presence of social and communication deficits in children with ADHD (Cooper et al, 2014).…”

Social Visual Perception Under the Eye of Bayesian Theories in Autism Spectrum Disorder Using Advanced Modeling of Spatial and Temporal Parameters

“…Furthermore, in accordance with recent studies suggesting that social impairments are more pronounced in comorbid cases compared to individuals without this comorbidity ( 55 – 57 ), here only the ASD+ADHD comorbid group manifested reduced social perception both in transition and fixation variables. However, it is important to consider that until the release of the new diagnostic guidelines ( 1 ), few eye tracking studies in social cognition distinguished between these groups ( 19 , 58 ). Therefore, it is unclear if previous studies recruited participants with comorbid ASD+ADHD in their ASD groups and if the overall performance of the reported ASD group was influenced from the comorbid participants.…”

Longitudinal Study of High and Low Functioning Preschool Children with ASD and the Progress Made Following Therapeutic Intervention

“…More children with average intelligence had ADH problems (77.20%) as opposed to low functioning (26.33%). A number of authors stress the co-occurrence of ADHD in children with ASD and place the incidence between 30% and 80% (Carrascosa-Romero & De Cabo-De La Vega, 2015). Shared heritability (Rommelse, Frankle, & Geurts, 2010) and shared endophenotypes (Holtman, Bölte, & Pousta, 2007) could explain the high co-incidence.…”