A Prospective Study of the Emergence of Early Behavioral Signs of Autism

Abstract

Objective-To examine prospectively the emergence of behavioral signs of autism in the first years of life in infants at low and high risk for autism.Method-A prospective longitudinal design was used to compare 25 infants later diagnosed with an autism spectrum disorder (ASD) with 25 gender-matched low-risk children later determined to have typical development. Participants were evaluated at 6, 12, 18, 24, and 36 months of age.Correspondence to: Dr. Ozonoff, M.I.N.D. Institute, University of California Davis Health System, 2825 50 th Street, Sacramento CA 95817; sally.ozonoff@ucdmc.ucdavis.edu. Disclosure: Drs. Ozonoff, Iosif, Cook, Hutman, Rogers, Rozga, Sigman, Steinfeld, and Young, and Mr. Baguio, Ms. Hill, and Ms. Sangha report no biomedical financial interests or potential conflicts of interest.Editorial support for the preparation of this article was provided by Diane Larzelere, UC Davis. NIH Public AccessAuthor Manuscript J Am Acad Child Adolesc Psychiatry. Author manuscript; available in PMC 2010 August 17. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptFrequencies of gaze to faces, social smiles, and directed vocalizations were coded from video and rated by examiners.Results-The frequency of gaze to faces, shared smiles, and vocalizations to others were highly comparable between groups at 6 months of age, but significantly declining trajectories over time were apparent in the group later diagnosed with ASD. Group differences were significant by 12 months of age on most variables. Although repeated evaluation documented loss of skills in most infants with ASD, most parents did not report a regression in their child's development.Conclusions-These results suggest that behavioral signs of autism are not present at birth, as once suggested by Kanner, but emerge over time through a process of diminishment of key social communication behaviors. More children may present with a regressive course than previously thought, but parent report methods do not capture this phenomenon well. Implications for onset classification systems and clinical screening are also discussed. KeywordsAutism; Onset; Infancy; Regression This study examined when and how behavioral signs of autism spectrum disorders (ASD) emerge in the first years of life. Most previous investigations of this topic have been retrospective, relying on parent report of earlier development or analysis of home videotape of infants later diagnosed with ASD. The existing literature suggests that behavioral signs of autism emerge in two different patterns, an early onset and a regressive course.Retrospective studies have demonstrated that children with early-onset ASD differ from agematched children with delayed and typical development in orienting to name, gaze to faces, joint attention, and affect sharing. [1][2][3][4][5][6] Differences are most evident in the second year of life 7 but some studies have detected signs of ASD before the first birthday. 1,5,8 This early onset pattern is thought to occur in the majority of indiv...

La pragmatique dans les troubles du spectre autistique

“…Certains y voient un manque de préférence inné pour les visages humains, qui entraînerait, dans un effet domino, un manque d'expertise dans la détection des expressions faciales [42]. D'autres études, pourtant, ne trouvent aucune différence entre bébés avec TSA et ceux au développement typique au niveau de la quantité d'attention visuelle accordée aux visages et aux yeux dans les tout premiers mois de vie ; cependant, autour de 12 mois, le temps passé à fixer les visages décroît sensiblement chez les bébés avec autisme [43,44]. On l'aura compris : même si des déficits socio-pragmatiques constituent indubitablement une caractéristique centrale de l'autisme, leur nature, leurs conséquences sur le développement et leurs corrélats neurocognitifs constituent un domaine de recherche crucial, qui exige un effort interdisciplinaire continu.…”

Identificação dos primeiros sintomas do autismo pelos pais

“…Entretanto, investigações baseadas em vídeos domésticos ou pesquisas prospectivas mostram que os comprometimentos sociais são os sinais que mais frequentemente aparecem, sendo anteriores ao desenvolvimento da linguagem oral (Saint-Goerges et al, 2010;Ozonoff et al, 2010). Os comprometimentos na área da linguagem, mais frequentemente identificados pelos pais, foram reconhecidos entre o primeiro e o segundo ano de vida da criança.…”

“…Tais achados são similares aos de outros estudos realizados com base na análise de vídeos domésticos (ver Saint-Georges et al, 2010, para uma revisão). Ozonoff et al (2010), através de um estudo prospectivo e longitudinal, que comparou o desenvolvimento de bebês posteriormente diagnosticados com TEA com o de bebês com desenvolvimento típico, encontraram que a frequência do olhar para faces, do sorriso social e das vocalizações só começou a declinar a partir dos seis meses de idade no grupo com TEA. Antes disso, os grupos eram altamente comparáveis, o que chama a atenção para o segundo semestre de vida como um período crítico na emergência de comprometimentos mais substanciais do espectro.…”

The complex genetics in autism spectrum disorders

“…Children with ASD usually experience a developmental regressive course during which behavioral signs of ASD occur over time [174]. For example, those with childhood disintegrative disorder, a rare form of low-functioning ASD, undergo the complete loss of certain language and social abilities that they had previously learned [175].…”