Evidence-Based Reviews

Autism spectrum disorder: Keys to early detection and accurate diagnosis

Author and Disclosure Information

Careful attention is required for early detection and to rule out other conditions


 

References

FIRST OF 2 PARTS

Autism spectrum disorder (ASD) is a complex, heterogenous neurodevelopmental disorder with genetic and environmental underpinnings, and an onset early in life.1-9 It affects social communication, cognition, and sensory-motor domains, and manifests as deficits in social reciprocity, repetitive behavior, restricted range of interests, and sensory sensitivities.6,10-14 In recent years, the prevalence of ASD has been increasing.3,6,10 A large percentage of individuals with ASD experience significant social deficits in adulthood,10 which often leads to isolation, depressive symptoms, and poor occupational and relationship functioning.15,16 Interventions in early childhood can result in significant and lasting changes in outcome and in functioning of individuals with ASD.

This article provides an update on various aspects of ASD diagnosis, with the goal of equipping clinicians with knowledge to help make an accurate ASD diagnosis at an early stage. Part 1 focuses on early detection and diagnosis, while Part 2 will describe treatment strategies.

Benefits of early detection

Substantial research has established that early intervention confers substantial benefits for outcomes among children with ASD.2,3,5,6,9,13,14,16-22 Earlier age of intervention correlates with greater developmental gain and symptom reduction.21,23 The atypical neural development responsible for ASD likely occurs much earlier than the behavioral manifestations of this disorder, which implies that there is a crucial period to intervene before behavioral features emerge.1 This necessitates early recognition of ASD,9,17 and the need for further research to find novel ways to detect ASD earlier.

In the United States, children with ASD are diagnosed with the disorder on average between age 3 and 4 years.6,24 However, evidence suggests there may be a prodromal phase for ASD during the first several months of life, wherein infants and toddlers exhibit developmentally inadequate communication and social skills and/or unusual behaviors.18 Behavioral signs suggestive of ASD may be evident as early as infancy, and commonly earlier than age 18 months.1,17,19 Problems with sleeping and eating may be evident in early childhood.19 Deficits in joint attention may be evident as early as age 6 months to 8 months. Research suggests that a diagnosis of ASD by trained, expert professionals is likely to be accurate at the age of 2, and even as early as 18 months.6,24

In a prospective study, Anderson et al25 found that 9% of children who were diagnosed with ASD at age 2 no longer met the diagnostic criteria for ASD by adulthood.6 Those who no longer met ASD criteria were more likely to have received early intervention, had a verbal IQ ≥70, and had experienced a larger decrease in repetitive behaviors between ages 2 and 3, compared with other youth in this study who had a verbal IQ ≥70. One of the limitations of this study was a small sample size (85 participants); larger, randomized studies are needed to replicate these findings.25

Continue to: Characteristics of ASD...

Pages

Next Article: