Young children who screen positive for autism: Stability, change and "comorbidity" over two years.
BACKGROUND
Autism spectrum disorder (ASD) is a developmental disorder with a wide variety of clinical phenotypes and co-occurrences with other neurodevelopmental conditions. Symptoms may change over time.


OBJECTIVE
The aim of the present study was to prospectively follow 96 children, initially assessed for suspected ASD at an average age of 2.9 years.


METHODS
All children had been identified with autistic symptoms in a general population child health screening program, and had been referred to the Child Neuropsychiatry Clinic in Gothenburg, Sweden for further assessment by a multi-professional team at Time 1 (T1). This assessment included a broad neurodevelopmental examination, structured interviews, a cognitive test and evaluations of the child́s adaptive and global functioning. Two years later, at Time 2 (T2), the children and their parents were invited for a follow-up assessment by the same team using the same methods.


RESULTS
Of the 96 children, 76 had met and 20 had not met full criteria for ASD at T1. Of the same 96 children, 79 met full ASD criteria at T2. The vast majority of children with ASD also had other neurodevelopmental symptoms or diagnoses. Hyperactivity was observed in 42% of children with ASD at T2, and Intellectual Developmental Disorder in 30%. Borderline Intellectual Functioning was found in 25%, and severe speech and language disorder in 20%. The children who did not meet criteria for ASD at T2 had symptoms of or met criteria for other neurodevelopmental/neuropsychiatric disorders in combination with marked autistic traits. Changes in developmental profiles between T1 and T2 were common in this group of young children with ASD. The main effect of Cognitive level at T1 explained more than twice as much of the variance in Vineland scores as did the ASD subtype; children with IDD had significantly lower scores than children in the BIF and AIF group. Co-existence with other conditions was the rule.


CONCLUSIONS
Reassessments covering the whole range of these conditions are necessary for an optimized intervention-adapted to the individual child's needs.
Gillberg Neuropsychiatry Centre, Sahlgrenska Academy, University of Gothenburg, Sweden; Department of Child and Adolescent Psychiatry, NU Hospital Organization, Uddevalla, Sweden. Electronic address: anne-katrin.kantzer@vgregion.se.
Anne-Katrin
AK
Kantzer
Gillberg Neuropsychiatry Centre, Sahlgrenska Academy, University of Gothenburg, Sweden.
Elisabeth
E
Fernell
Gillberg Neuropsychiatry Centre, Sahlgrenska Academy, University of Gothenburg, Sweden; Institute of Psychology, Stockholm University, Stockholm, Sweden.
Joakim
J
Westerlund
Gillberg Neuropsychiatry Centre, Sahlgrenska Academy, University of Gothenburg, Sweden; Child Neuropsychiatry Clinic, University of Gothenburg, Gothenburg, Sweden.
Bibbi
B
Hagberg
Gillberg Neuropsychiatry Centre, Sahlgrenska Academy, University of Gothenburg, Sweden.
Christopher
C
Gillberg
Gillberg Neuropsychiatry Centre, Sahlgrenska Academy, University of Gothenburg, Sweden; Division of Speech and Language Pathology, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
Carmela
C
Miniscalco
D001321:Autistic Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D002675:Child, Preschool; D003071:Cognition; D015897:Comorbidity; D018479:Early Intervention, Educational / Q000379:methods / Q000458:organization & administration; D005260:Female; D006801:Humans; D007805:Language Development Disorders / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D020380:Needs Assessment; D065886:Neurodevelopmental Disorders / Q000175:diagnosis / Q000453:epidemiology; D009483:Neuropsychological Tests; D013548:Sweden / Q000453:epidemiology; D063189:Symptom Assessment / Q000379:methods / Q000706:statistics & numerical data
Autism spectrum disorder; Comorbidity; Diagnostic stability; ESSENCE; Follow-up; Preschool community study