Children with borderline intellectual functioning and autism spectrum disorder: developmental trajectories from 4 to 11 years of age.

BACKGROUND: Studies on autism have tended to focus either on those with intellectual disability (ie, those with intellectual quotient [IQ] under 70) or on the group that is referred to as "high-functioning", that is, those with borderline, average or above average IQ. The literature on cognition and daily functioning in autism spectrum disorder combined specifically with borderline intellectual functioning (IQ 70-84) is limited. METHODS: From a representative group of 208 preschool children diagnosed with autism spectrum disorder, those 50 children in the group with borderline intellectual functioning at ages 4.5-6.5 years were targeted for follow-up at a median age of 10 years. A new cognitive test was carried out in 30 children. Parents were interviewed with a semi-structured interview together with the Vineland Adaptive Behavior Scales (n=41) and the Autism-Tics, attention-deficit/hyperactivity disorder (AD/HD) and other comorbidities inventory (A-TAC) (n=36). RESULTS: Most children of interviewed parents presented problems within several developmental areas. According to A-TAC and the clinical interview, there were high rates of attention deficits and difficulties with regulating activity level and impulsivity. Vineland Adaptive Behavior Scales composite scores showed that at school age, a majority of the children had declined since the previous assessment at ages between 4.5 and 6.5 years. Almost half the tested group had shifted in their IQ level, to below 70 or above 84. CONCLUSION: None of the children assessed was without developmental/neuropsychiatric problems at school-age follow-up. The results support the need for comprehensive follow-up of educational, medical and developmental/neuropsychiatric needs, including a retesting of cognitive functions. There is also a need for continuing parent/family follow-up and support.

Autism spectrum disorders before diagnosis: results from routine developmental surveillance at 18 months.

AIM: This study investigated the results from the national, routine 18-month developmental surveillance at Child Healthcare Centres (CHCs) on children later diagnosed with autism spectrum disorder (ASD). METHODS: Child Healthcare Centre records of 175 children, diagnosed with ASD before 4.5 years in Stockholm County, Sweden, were reviewed regarding the results of the eight-item neurodevelopmental surveillance. Results were contrasted with normative data from the general child population in Stockholm County. RESULTS: More than one-third of the total ASD group, including half of the group with ASD and intellectual disability (ID), did not pass the required number of items, compared to one in 50 in the general child population. Of those with ASD and ID who had passed, more than one-third experienced developmental regression after 18 months of age. If the CHC surveillance had considered reported regulatory problems - crying, feeding and sleeping - then another 10% of the children with ASD and ID could have been identified during this surveillance. CONCLUSION: The existing CHC surveillance traced half of the group of children who were later diagnosed with ASD combined with intellectual disability. Adding an item on regulatory problems to the 18-month surveillance would have increased this number by another 10%.

Preschoolers with Autism Spectrum Disorder Followed for 2 Years: Those Who Gained and Those Who Lost the Most in Terms of Adaptive Functioning Outcome.

Clinical predictors of 2-year outcome in preschoolers with ASD were studied in a population-based group of very young children with ASD (n = 208). Children who gained the most (n = 30) and lost the most (n = 23), i.e., increased or decreased their adaptive functioning outcome according to the Vineland Composite Score between study entry (T1) and follow-up (T2), 2 years later were compared. Individual factors that differed significantly between the two outcome groups were cognitive level, age at referral, not passing expected milestones at 18 months, autistic type behavior problems and regression. However, logistic regression analysis showed that only cognitive level at T1 (dichotomized into IQ < 70 and IQ ≥ 70) made a unique statistically significant contribution to outcome prediction (p = <.001) with an odds ratio of 18.01. The findings have significant clinical implications in terms of information at diagnosis regarding clinical prognosis in ASD.

Children with autism spectrum disorders who do not develop phrase speech in the preschool years.

There is uncertainty about the proportion of children with autism spectrum disorders who do not develop phrase speech during the preschool years. The main purpose of this study was to examine this ratio in a population-based community sample of children. The cohort consisted of 165 children (141 boys, 24 girls) with autism spectrum disorders aged 4-6 years followed longitudinally over 2 years during which time they had received intervention at a specialized autism center. In this study, data collected at the 2-year follow-up were used. Three categories of expressive language were defined: nonverbal, minimally verbal, and phrase speech. Data from the Vineland Adaptive Behavior Scales-II were used to classify expressive language. A secondary objective of the study was to analyze factors that might be linked to verbal ability, namely, child age, cognitive level, autism subtype and severity of core autism symptoms, developmental regression, epilepsy or other medical conditions, and intensity of intervention. The proportion of children who met the criteria for nonverbal, minimally verbal, and phrase speech were 15%, 10%, and 75%, respectively. The single most important factor linked to expressive language was the child's cognitive level, and all children classified as being nonverbal or minimally verbal had intellectual disability.

Autism and developmental profiles in preschoolers: stability and change over time.

AIM: Increasing numbers of young children are now being diagnosed with autism spectrum disorder (ASD). This study aimed to analyse developmental trajectories in a representative group of preschool children with ASD. METHOD: In a naturalistic study, 208 preschool children with different subtypes of ASD were followed over a 2-year period. Their trajectories, as regards persistence of ASD diagnoses, developmental/intellectual levels, adaptive functioning and expressive speech, were monitored. RESULTS: Developmental profiles showed considerable change over time, especially in children with atypical autism and in those with developmental delay/borderline intellectual functioning at their first assessment. Approximately 50% of the children were found to have intellectual disability (ID) at follow-up and, of these, the majority had severe ID. This was in contrast to the first assessment by the referral team when ID had rarely been mentioned or discussed. CONCLUSION: Changes in developmental profiles during preschool years are common in children with ASD. This implies that reassessments, covering different developmental areas, are needed. Such follow-up assessments prior to the start of school will yield a more valid estimation of the child's general cognitive level and a more accurate ASD diagnosis and thus form a better basis for realistic educational planning and intervention.

Autism, processing speed, and adaptive functioning in preschool children.

OBJECTIVES: To study cognitive test profiles with a focus on processing speed in a representative group of preschool children with autism spectrum disorder (ASD) and relate processing speed to adaptive functioning. METHODS: Cognitive assessments were performed in 190 3.6-6.6-year-old children (164 boys and 26 girls) with ASD, using either Griffiths' developmental scales (n = 77) or the Wechsler Preschool and Primary Scale of Intelligence-Third Edition (WPPSI-III) (n = 113). Cognitive data were related to adaptive functioning as measured by Vineland Adaptive Behavior Scales (VABS). RESULTS: Cognitive profiles were characterized by low verbal skills. Low processing speed quotients (PSQs) were found in 66 (78%) of the 85 children who were able to participate in the processing speed subtests. Except for Socialization, all VABS domains (Communication, Motor Skills, Daily Living Skills, and Adaptive Behavior Composite scores) correlated significantly with PSQ. Multiple regression analysis showed that PSQ predicted 38%, 35%, 34%, and 37% of the variance for Communication, Daily Living Skills, Motor Skills, and total Adaptive Composite scores, respectively. CONCLUSION: Preschool children with ASD had uneven cognitive profiles with low verbal skills, and, relatively, even lower PSQs. Except for Socialization, adaptive functioning was predicted to a considerable degree by PSQ.

Medical conditions affect the outcome of early intervention in preschool children with autism spectrum disorders.

The aim was to explore the frequency of genetic and other medical conditions, including epilepsy, in a population-based group of 208 preschool children with early diagnosis of Autism spectrum disorders (ASD) and to relate outcome at a 2-year follow-up to the co-existing medical findings. They had all received early intervention. The Vineland Adaptive Behaviour Scales (VABS-II) composite score served as the primary outcome measure. In the total group, 38/208 children (18 %) had a significant medical or genetic condition. Epilepsy was present in 6.3 % at the first assessment and in 8.6 % at follow-up and was associated with more severe intellectual impairment. A history of regression was reported in 22 %. Children with any medical/genetic condition, including epilepsy, as well as children with a history of regression had significantly lower VABS-II scores at the 2-year follow-up. Children with a medical/genetic condition, including epilepsy, had been diagnosed with ASD at an earlier age than those without such conditions, and early age at diagnosis also correlated negatively with adaptive functioning outcome. The results underscore the importance of considering medical/genetic aspects in all young children with ASD and the requirement to individualize and tailor interventions according to their specific needs.

Gaze performance in children with autism spectrum disorder when observing communicative actions.

The main purpose of this eye tracking study was to map the correlates of gaze performance in a brief test of spontaneous gaze and point-gesture following in young children with autistic disorder (AD), Pervasive developmental disorder-not otherwise specified (PDD-NOS), or typical development (TD). Gaze measures included the children's spontaneous tendency to look at the correct (attended) toy, and the latency of their correct responses. In addition to group differences (AD vs. TD), we found that in AD, accuracy of performance was specifically related to adaptive communication skills. The study also indicated that the latency of correct gaze shifts is related to verbal intelligence. These results have direct implications for our understanding of (responsive) joint attention impairments in AD.

Language and communication skills in preschool children with autism spectrum disorders: contribution of cognition, severity of autism symptoms, and adaptive functioning to the variability.

This study examined the contribution of cognitive function, severity of autism, and adaptive functioning to the variability in language and communication skills in 129 preschool children (aged 24-63 months) with autism spectrum disorder (ASD). Participants were selected from a representative research cohort of 208 preschool children on the basis of caregiver completion of the MacArthur-Bates Communicative Development Inventories (CDI). The children were classified into three cognitive groups: (a) Normal intelligence; (b) Developmental delay; and (c) Intellectual disability. Autism symptom severity was measured by the Autistic Behavior Checklist (ABC), and adaptive functioning by the Daily Living Skills (DLS) and Socialization (Soc) subscales from the Vineland Adaptive Behavior Scales. For each of five CDI variables (Phrases understood, Words understood, Words produced, Gestures and actions, and Language use), the contribution of cognition, severity of autism symptoms, and adaptive functioning to the variability was examined. Cognition and age explained about half or more of the variance in the four verbal language CDI variables, but only about one fourth of the variance in the non-verbal communication variable Gestures and actions. Severity of autism symptoms and the two adaptive measures (DLS and Soc) each only accounted for a few percent more of the variance in the four CDI language variables; however, for Gestures and actions, an additional 11-21% of the variance was accounted for. In conclusion, for children with ASD, receptive and expressive language is mainly related to cognitive level, whereas non-verbal communication skills seem to also be related to severity of autism symptoms and adaptive functioning.

Early intervention in 208 Swedish preschoolers with autism spectrum disorder. A prospective naturalistic study.

Early intervention has been reported to improve outcome in children with autism spectrum disorders (ASDs). Several studies in the field have been randomized controlled trials (RCTs). The aim of this study was to assess ASD outcome in a large naturalistic study. Two hundred and eight children, aged 20-54 months, with a clinical diagnosis of ASD were given intervention and monitored prospectively in a naturalistic fashion over a period of 2 years. The toddlers were considered representative of all but the most severely multiple disabled preschool children with ASD in Stockholm county. They fell into three cognitive subgroups: one with learning disability, one with developmental delay, and one with normal intellectual functioning. Data on intervention type and intensity were gathered prospectively in a systematic fashion. Intervention was classified into intensive applied behaviour analysis (ABA) and non-intensive, targeted interventions, also based on ABA principles. Children were comprehensively assessed by a research team before the onset of intervention, and then, again, 2 years later. Change in Vineland adaptive behaviour scales composite scores from intake (T1) to leaving the study (T2) was set as the primary outcome variable. The research team remained blind to the type and intensity of interventions provided. One hundred and ninety-eight (95%) of the original samples stayed in the study throughout the whole 2-year period and 192 children had a complete Vineland composite score results both at T1 and T2. Vineland composite scores increased over the 2-year period. This increase was accounted for by the subgroup with normal cognitive functioning. There was no significant difference between the intensive and non-intensive groups. Individual variation was considerable, but no child in the study was "problem-free" at follow-up. Our data do not support that children with ASD generally benefit more from the most intensive ABA intervention programs than from less intensive interventions or targeted interventions based on ABA.

Sensory abnormalities in autism. A brief report.

Sensory abnormalities were assessed in a population-based group of 208 20-54-month-old children, diagnosed with autism spectrum disorder (ASD) and referred to a specialized habilitation centre for early intervention. The children were subgrouped based upon degree of autistic symptoms and cognitive level by a research team at the centre. Parents were interviewed systematically about any abnormal sensory reactions in the child. In the whole group, pain and hearing were the most commonly affected modalities. Children in the most typical autism subgroup (nuclear autism with no learning disability) had the highest number of affected modalities. The children who were classified in an "autistic features" subgroup had the lowest number of affected modalities. There were no group differences in number of affected sensory modalities between groups of different cognitive levels or level of expressive speech. The findings provide support for the notion that sensory abnormality is very common in young children with autism. This symptom has been proposed for inclusion among the diagnostic criteria for ASD in the upcoming DSM-V.

Developmental profiles in preschool children with autism spectrum disorders referred for intervention.

The aim was to characterize the panorama of developmental disorders in 208 preschool children with a clinical diagnosis of autism spectrum disorder (ASD), referred to a specialized centre, the Autism Centre for Young Children (ACYC), for intervention. At the centre, a research team examined all children according to structured protocols and interviews. All available test data from their assessments prior to referral were scrutinized. The boy:girl ratio was 5.5:1. In 22% of the total group a period of regression, including speech and language, had occurred. Epilepsy had been diagnosed in 6% of the children. In 38% of the children there was a definite or highly suspected learning disability/mental retardation according to cognitive test results. About the same proportion had a developmental delay that at the time of assessment could not be definitely classified and in 23% there were clear indications of a normal intellectual function. About 40% of the group exhibited hyperactivity. Differences in expressive vocabulary and adaptive functioning were strongly related to cognitive level. About 20% of the group had AD as the dominating developmental disorder, i.e., they represented a clinical picture of "classic" autism. The majority in this group also had learning disability. Another 20%, had ASD combined with a normal intellectual level, some of these conformed to the clinical picture of Asperger syndrome. In a relatively large group (more than half) learning disability or a general developmental delay was as evident as the ASD. In a smaller group (8%) ASD criteria were questionably met. In this group attention deficits in connection with speech and language problems were prominent. The highly individual developmental profiles seen in children with ASDs have to be taken into account when planning intervention and follow-up. The children's medical characteristics also vary considerably and will be detailed in a further report.