Patterns of development in young children with autism
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《美国医学杂志》
Department of Pediatrics, Post Graduate Institute of Medical Education and Research, Sector 12, Chandigarh-160 012, India
Abstract
OBJECTIVE: To determine the extent to which the developmental profile of children less than 4 years can help in distinguishing children with autism from children with developmental delay. METHODS: Subjects were 32 children with autism as per the DSM IV criteria and 32 children with developmental delay matched on chronological and academic age. The Developmental Profile II was used to assess the developmental functioning in five domains including physical, social, self help, academic, and communication. RESULTS: The two groups showed significantly different developmental profiles and these differences were accounted for mainly by significantly lower social skills and superior motor skills in the autistic group as compared to the developmentally delayed group. CONCLUSION: Developmental Profile II may help in distinguishing young children with autistic disorder from non-autistic children with comparable developmental delays.
Keywords: Autistic disorder; Developmental profile; Young children
Autistic spectrum disorders consist of a group of developmental behavioral disorders which are characterized by abnormal social interaction, qualitatively impaired communication skills, and restricted repertoire of activities and interests.[1] It is now known that autistic spectrum disorders (ASD) are heterogeneous disorders, with milder forms being more common than the classic form. Recent studies have estimated the prevalence of approximately 1 in 1000 for autistic disorder and 2 or more in 1000 children for ASD. [2],[3],[4]
Several studies have emphasized the importance of early recognition of children with autism as evidence indicates reduction in abnormal behavior and increased acquisition of skills resulting from participation in intensive, specialized early intervention programs.[5]-[6] Despite the importance of early recognition, studies have demonstrated considerable delay between parents recognition that something is wrong with their child and the diagnosis of autism. For example, Howlin and Moore[7] in a study of 1295 families in UK found that 50% of parents report recognizing problems by 2 years and 93% by 3 years, yet fewer than 10% of the children were diagnosed at initial presentation and only 50% received a diagnosis by age 5. The diagnosis of autism is often not made until 2 to 3 years after symptoms are recognized, mainly because of incorrectly diagnosing the children and the difficulty in distinguishing children with autistic disorder from children with developmental delay.[8]
Some of the early indicators of autism have been investigated in the literature from retrospective parental reports and videotapes of the children taken before the diagnosis.[9] In a study, Gillberg et al[10] studied 28 children prospectively aged 3 years or less and found that isolation from surroundings, failure to play like other children, apparent deafness were some of the items that discriminated autism from developmental delay. In another study, Ohta et al[11] found that early parental concerns that discriminated autism from general developmental delay included a poor response to others, poor peer relationships, and ignoring others. Baranak [12] showed that abnormalities in orientation to visual stimuli, aversion to touch and delayed response to name characterized autism but not developmental delay or typically developing infants as early as 9 months of age.
Dahlgren and Gillberg[13] used an 130 items questionnaire to obtain retrospective information from parents of 26 autistic children, 17 developmentally matched children with mental retardation, and 22 population-matched typically developing children. The authors found that 18 items discriminated the children with autism from the other two groups. These items included social behaviors such as appearing isolated from surroundings, not smiling when expected, empty gaze, difficulty in imitating movements; sensory behaviors such as strange reactions to sounds, overexcited when tickled, not playing like other children, and showing attachment to unusual objects.
It is thus evident that young autistic children can be differentiated from those with developmental delay on the basis of many behavioral and diagnostic features. However, the question: Can young children with autistic disorder be reliably distinguished from developmentally delayed children on the basis of their developmental profile has not received empirical attention in the literature. It is plausible that young children with autism may exhibit unique developmental profile that can facilitate early identification and diagnosis.
Keeping this in view, the primary goal of the present study was to determine the extent to which the developmental profile of the children with autistic disorder can help in distinguishing children with autism from developmentally delayed children.
Materials and Methods
Subjects : The subjects in the study included 64 children who were evaluated in the outpatient psychology services at the Department of Pediatrics, Post Graduate Institute of Medical Education and Research, a tertiary care hospital in North India. All children had been referred for evaluations by pediatricians for concerns about development. Inclusion criteria were (i) chronological age less than 4 years, (ii) primary diagnosis of autistic disorder or developmental delay, and (iii) absence of significant sensory or motor impairments.
The autistic group consisted of 32 children (29 boys, 3 girls) ranging in age from 21 to 47 months (mean age = 34.2. S.D = 7.74). In all cases, the diagnosis of autism had been assigned on the basis of information obtained during a multidisciplinary assessment. All children in this group met the diagnosis of autistic disorder as per the DSM IV criteria.[1] In addition, the Childhood Autism Rating Scale (CARS)[14] was completed for all subjects. All subjects obtained CARS scores within the autistic range. None of the subjects had received a formal diagnosis of autistic disorder prior to his or her evaluation at the hospital.
The second group, the developmentally delayed group, also consisted of 32 children (Mean age=33.7 months, S.D.= 9.9) who received a primary diagnosis of developmental delay. These children were individually matched to the autistic group on chronological age and academic age (on the Developmental Profile II) both within 4 months. No child in this group met the criteria for autistic disorder.
Procedure
Developmental Assessment: A detailed developmental assessment was done using the Developmental Profile II (DP II).[15] The DP II is an 186 items inventory which assesses the child's developmental status from birth to 9 years. The DP II assesses child's developmental age in five domains namely physical, social, self-help, academic, and communication. Each sub-scale produces a developmental age that is subtracted from the chronological age. The resulting "months differential" is compared with a cut off that reveals whether children are advanced, normal, borderline or delayed in their development. One of the most important features of the DP II is that its academic scale can be converted into an IQ score. The academic scale assesses a range of skills necessary for success in school including language, cognition and scholastic accomplishments. The IQ calculated from the academic scale has been found to have moderate to high correlation with conventional measures of intelligence. In the present study the IQ of the subjects was calculated form the academic sub scale of DP II.
Results
The description of the two samples is presented in table1. The t test revealed no significant differences in chronological age, academic age and IQ between the autistic and developmentally delayed group. However, there were significant differences between the two groups on maternal education and socio-economic status. The mothers of children with autism had completed on an average significantly more years of schooling as compared to the control group (t=2.43, p<.01 ). Moreover, the mean socio economic status index was also significantly higher (t= 4.61 p<.000) for the autistic group than the control group. Chi-square analyses for sex and residence were found to be significant. There were significantly (c2=22.6; p<0.000) more males in the autistic group than the control group. There were also significantly higher number of autistic children belonging to urban areas as compared to the developmentally delayed group.
Discussion
The main question addressed in the paper was to determine whether young children with autism would show different patterns of developmental profile as compared to developmentally matched non-autistic children. The present study results indicate that the two groups of children showed different patterns of profiles and these differences were accounted for mainly by significantly lower social skills and superior physical skills in the autistic group as compared with the developmentally delayed group. The differences between the two groups on social and physical skills cannot be attributed to differences in cognitive level, as both the groups were matched on chronological and academic age.
It appears that impaired development of social skills and superior physical skills may reflect an inherent difference between the children with and without autism. Although these results are not surprising, given that social deficits are well - documented in children with autism and are central to the diagnosis.[1],[16]-[17] The present study adds to the literature in its finding that this pattern was obtained from an instrument which is based on parental report and is designed to provide information about child's developmental functioning rather than diagnosis.
Previous studies which have examined adaptive behavior functioning of children with autism have also found a pattern of lower adaptive behavior relative to cognitive skills in autistic individuals. [18],[19],[20] In a recent study, Stone et al[21] examined the patterns of adaptive behavior in children with autism less than three years. The authors found lower communication and socialization skills relative to mental age for the autistic sample but daily living and motor skills were higher than mental age. Similar results were obtained by other studies.[22]-[23]
Conclusion
The present study results, therefore, provide some evidence that the developmental profile may distinguish very young children with autism from non-autistic children with comparable developmental delays. The DP II may be used as a screening test to make reasonably accurate referral decisions. However, whether the developmental profile is useful in early identification and diagnosis of autism requires more research. Replication of these results on larger samples will be necessary before firmer conclusion can be drawn.
References
1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed (DSM IV). Washington, DC: American Psychiatric Association, 1994.
2. Honda H, Schimizu Y, Misumi K, Niimi M, Ohashi Y. Cumulative incidence and prevalence of childhood autism in children in Japan. Br J Psychiatry 1996; 169: 228-235.
3. Fombonne E. The epidemiology of autism: a review. Psychol Med 1999; 29: 769-789.
4. Charman T, Baron-Cohen S, Swettenhaur J, Wheelwright S, Drew A. Instrument for autism at 18 months of age: A 6 year follow up study. J Am Acad Child Adolesc Psychiatry 2000; 39: 694-702.
5. Lovaas OI. Behavioral treatment and normal educational and intellectual functioning in young autistic children. J Consult Clin Psychol 1987; 55: 3-9.
6. Rogers SJ. Empirically supported comprehensive treatments for young children with autism. J Clin Child Psychol 1998; 27: 167-178.
7. Howlin P, Moore A. Diagnosis of autism. A survey of over 1200 patients in the UK. Autism 1997; 1: 135-162.
8. Filepek PA, Accardo PJ, Ashwal S, Baranek GT, Cook EH, Dawson G et al. Practice parameter. Screening and diagnosis of autism: report of the Quality Standards Subcommittee of American Academy of Neurology and the Child Neurology Society, Neurology 2000; 55: 468-479.
9. Stone WL. Autism in infancy and early childhood. In D Cohen, FR Volkmar, eds. Handbook of Autism and Pervasive Developmental Disorders, 2nd Ed. Wiley, 1997; 266-282.
10. Gillberg C, Ehlers S, Schaumann H, Jakobson G, Dahlgren SO, Lindbolm R, Bagenholm A, Tjuus T, Blidner E. Autism under age 3 years: A clinical study of 28 cases referred for autistic symptoms in infancy. J Child Psychol Psychiatry 1990; 31: 921-934.
11. Ohta M, Nagai Y, Hara H, Sasaki M. Parental perception of behavioral symptoms in Japanese autistic children. J Autism Dev Disord 1987; 17: 549-563.
12. Baranek GT. Autism during infancy: A retrospective video analysis of sensory-motor and social behavior at 9-12 months of age. J Autism Dev Disord 1999; 29: 213-224.
13. Dahlgren SO, Gillberg C, Symptoms in the first two years of life. Euro Arch Psychiatry Neurol Sc 1989;238: 169-174.
14. Schopler E, Reichler RJ, Renner BR. The Childhood Autism Rating Scale . Los Angeles; Western Psychological Services,1988.
15. Alpern B, Boll T, Shearer M. Developmental Profile II (DP II). Los Angeles CA; Western Psychological Services.
16. Mundy P, Sigman M. Specifying the nature of the social impairment in autism. In G. Dawson, ed. Autism: Nature, Diagnosis and Treatment. New York; Guilford, 1989; 1-21.
17. Volkmar FR, Carter A, Sparrow S, Cicchetti DV. Quantifying social development in autism. J Am Acad Child Adolesc Psychiatry 1993; 32: 627-632.
18. Freeman BJ, Ritvo ER, Yokota A, Childs J, Pollard J. WISC-R and Vineland Adaptive Behavior scale scores in autistic children. J Am Acad Child Adolesc Psychiatry 1988; 27: 428-429.
19. Freeman BJ, Rahbar B, Ritvo ER, Bice TL, Yokota A, Ritvo. The stability of cognitive and behavioral parameters in autism: A twelve- year prospective study. J Am Acad Child Psychiatry 1991; 30: 479-482.
20. Venter A, Lord C, Schopler E. A follow-up study of high functioning autistic children. J Child Psychol Psychiatry 1992; 33: 489-507.
21. Stone WL, Ousley OY, Hepburn SL, Hogan KL, Brown CS. Patterns of adaptive behavior in very young children with autism. Am J Ment Retard 1999; 104: 187-199.
22. Loveland KA, Kelly ML. Development of adaptive behavior in adolescents and young adults with autism and Down syndrome. Am J Ment Retard 1988; 93: 84-92.
23. Klin A, Volkmar FR, Sparrow S. Autistic social dysfunction: Some limitations of the theory of mind hypothesis. J Child Psychol Psychiatry Allied Disc 1992; 33: 861-876.(Malhi Prahbhjot, Singhi P)
Abstract
OBJECTIVE: To determine the extent to which the developmental profile of children less than 4 years can help in distinguishing children with autism from children with developmental delay. METHODS: Subjects were 32 children with autism as per the DSM IV criteria and 32 children with developmental delay matched on chronological and academic age. The Developmental Profile II was used to assess the developmental functioning in five domains including physical, social, self help, academic, and communication. RESULTS: The two groups showed significantly different developmental profiles and these differences were accounted for mainly by significantly lower social skills and superior motor skills in the autistic group as compared to the developmentally delayed group. CONCLUSION: Developmental Profile II may help in distinguishing young children with autistic disorder from non-autistic children with comparable developmental delays.
Keywords: Autistic disorder; Developmental profile; Young children
Autistic spectrum disorders consist of a group of developmental behavioral disorders which are characterized by abnormal social interaction, qualitatively impaired communication skills, and restricted repertoire of activities and interests.[1] It is now known that autistic spectrum disorders (ASD) are heterogeneous disorders, with milder forms being more common than the classic form. Recent studies have estimated the prevalence of approximately 1 in 1000 for autistic disorder and 2 or more in 1000 children for ASD. [2],[3],[4]
Several studies have emphasized the importance of early recognition of children with autism as evidence indicates reduction in abnormal behavior and increased acquisition of skills resulting from participation in intensive, specialized early intervention programs.[5]-[6] Despite the importance of early recognition, studies have demonstrated considerable delay between parents recognition that something is wrong with their child and the diagnosis of autism. For example, Howlin and Moore[7] in a study of 1295 families in UK found that 50% of parents report recognizing problems by 2 years and 93% by 3 years, yet fewer than 10% of the children were diagnosed at initial presentation and only 50% received a diagnosis by age 5. The diagnosis of autism is often not made until 2 to 3 years after symptoms are recognized, mainly because of incorrectly diagnosing the children and the difficulty in distinguishing children with autistic disorder from children with developmental delay.[8]
Some of the early indicators of autism have been investigated in the literature from retrospective parental reports and videotapes of the children taken before the diagnosis.[9] In a study, Gillberg et al[10] studied 28 children prospectively aged 3 years or less and found that isolation from surroundings, failure to play like other children, apparent deafness were some of the items that discriminated autism from developmental delay. In another study, Ohta et al[11] found that early parental concerns that discriminated autism from general developmental delay included a poor response to others, poor peer relationships, and ignoring others. Baranak [12] showed that abnormalities in orientation to visual stimuli, aversion to touch and delayed response to name characterized autism but not developmental delay or typically developing infants as early as 9 months of age.
Dahlgren and Gillberg[13] used an 130 items questionnaire to obtain retrospective information from parents of 26 autistic children, 17 developmentally matched children with mental retardation, and 22 population-matched typically developing children. The authors found that 18 items discriminated the children with autism from the other two groups. These items included social behaviors such as appearing isolated from surroundings, not smiling when expected, empty gaze, difficulty in imitating movements; sensory behaviors such as strange reactions to sounds, overexcited when tickled, not playing like other children, and showing attachment to unusual objects.
It is thus evident that young autistic children can be differentiated from those with developmental delay on the basis of many behavioral and diagnostic features. However, the question: Can young children with autistic disorder be reliably distinguished from developmentally delayed children on the basis of their developmental profile has not received empirical attention in the literature. It is plausible that young children with autism may exhibit unique developmental profile that can facilitate early identification and diagnosis.
Keeping this in view, the primary goal of the present study was to determine the extent to which the developmental profile of the children with autistic disorder can help in distinguishing children with autism from developmentally delayed children.
Materials and Methods
Subjects : The subjects in the study included 64 children who were evaluated in the outpatient psychology services at the Department of Pediatrics, Post Graduate Institute of Medical Education and Research, a tertiary care hospital in North India. All children had been referred for evaluations by pediatricians for concerns about development. Inclusion criteria were (i) chronological age less than 4 years, (ii) primary diagnosis of autistic disorder or developmental delay, and (iii) absence of significant sensory or motor impairments.
The autistic group consisted of 32 children (29 boys, 3 girls) ranging in age from 21 to 47 months (mean age = 34.2. S.D = 7.74). In all cases, the diagnosis of autism had been assigned on the basis of information obtained during a multidisciplinary assessment. All children in this group met the diagnosis of autistic disorder as per the DSM IV criteria.[1] In addition, the Childhood Autism Rating Scale (CARS)[14] was completed for all subjects. All subjects obtained CARS scores within the autistic range. None of the subjects had received a formal diagnosis of autistic disorder prior to his or her evaluation at the hospital.
The second group, the developmentally delayed group, also consisted of 32 children (Mean age=33.7 months, S.D.= 9.9) who received a primary diagnosis of developmental delay. These children were individually matched to the autistic group on chronological age and academic age (on the Developmental Profile II) both within 4 months. No child in this group met the criteria for autistic disorder.
Procedure
Developmental Assessment: A detailed developmental assessment was done using the Developmental Profile II (DP II).[15] The DP II is an 186 items inventory which assesses the child's developmental status from birth to 9 years. The DP II assesses child's developmental age in five domains namely physical, social, self-help, academic, and communication. Each sub-scale produces a developmental age that is subtracted from the chronological age. The resulting "months differential" is compared with a cut off that reveals whether children are advanced, normal, borderline or delayed in their development. One of the most important features of the DP II is that its academic scale can be converted into an IQ score. The academic scale assesses a range of skills necessary for success in school including language, cognition and scholastic accomplishments. The IQ calculated from the academic scale has been found to have moderate to high correlation with conventional measures of intelligence. In the present study the IQ of the subjects was calculated form the academic sub scale of DP II.
Results
The description of the two samples is presented in table1. The t test revealed no significant differences in chronological age, academic age and IQ between the autistic and developmentally delayed group. However, there were significant differences between the two groups on maternal education and socio-economic status. The mothers of children with autism had completed on an average significantly more years of schooling as compared to the control group (t=2.43, p<.01 ). Moreover, the mean socio economic status index was also significantly higher (t= 4.61 p<.000) for the autistic group than the control group. Chi-square analyses for sex and residence were found to be significant. There were significantly (c2=22.6; p<0.000) more males in the autistic group than the control group. There were also significantly higher number of autistic children belonging to urban areas as compared to the developmentally delayed group.
Discussion
The main question addressed in the paper was to determine whether young children with autism would show different patterns of developmental profile as compared to developmentally matched non-autistic children. The present study results indicate that the two groups of children showed different patterns of profiles and these differences were accounted for mainly by significantly lower social skills and superior physical skills in the autistic group as compared with the developmentally delayed group. The differences between the two groups on social and physical skills cannot be attributed to differences in cognitive level, as both the groups were matched on chronological and academic age.
It appears that impaired development of social skills and superior physical skills may reflect an inherent difference between the children with and without autism. Although these results are not surprising, given that social deficits are well - documented in children with autism and are central to the diagnosis.[1],[16]-[17] The present study adds to the literature in its finding that this pattern was obtained from an instrument which is based on parental report and is designed to provide information about child's developmental functioning rather than diagnosis.
Previous studies which have examined adaptive behavior functioning of children with autism have also found a pattern of lower adaptive behavior relative to cognitive skills in autistic individuals. [18],[19],[20] In a recent study, Stone et al[21] examined the patterns of adaptive behavior in children with autism less than three years. The authors found lower communication and socialization skills relative to mental age for the autistic sample but daily living and motor skills were higher than mental age. Similar results were obtained by other studies.[22]-[23]
Conclusion
The present study results, therefore, provide some evidence that the developmental profile may distinguish very young children with autism from non-autistic children with comparable developmental delays. The DP II may be used as a screening test to make reasonably accurate referral decisions. However, whether the developmental profile is useful in early identification and diagnosis of autism requires more research. Replication of these results on larger samples will be necessary before firmer conclusion can be drawn.
References
1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed (DSM IV). Washington, DC: American Psychiatric Association, 1994.
2. Honda H, Schimizu Y, Misumi K, Niimi M, Ohashi Y. Cumulative incidence and prevalence of childhood autism in children in Japan. Br J Psychiatry 1996; 169: 228-235.
3. Fombonne E. The epidemiology of autism: a review. Psychol Med 1999; 29: 769-789.
4. Charman T, Baron-Cohen S, Swettenhaur J, Wheelwright S, Drew A. Instrument for autism at 18 months of age: A 6 year follow up study. J Am Acad Child Adolesc Psychiatry 2000; 39: 694-702.
5. Lovaas OI. Behavioral treatment and normal educational and intellectual functioning in young autistic children. J Consult Clin Psychol 1987; 55: 3-9.
6. Rogers SJ. Empirically supported comprehensive treatments for young children with autism. J Clin Child Psychol 1998; 27: 167-178.
7. Howlin P, Moore A. Diagnosis of autism. A survey of over 1200 patients in the UK. Autism 1997; 1: 135-162.
8. Filepek PA, Accardo PJ, Ashwal S, Baranek GT, Cook EH, Dawson G et al. Practice parameter. Screening and diagnosis of autism: report of the Quality Standards Subcommittee of American Academy of Neurology and the Child Neurology Society, Neurology 2000; 55: 468-479.
9. Stone WL. Autism in infancy and early childhood. In D Cohen, FR Volkmar, eds. Handbook of Autism and Pervasive Developmental Disorders, 2nd Ed. Wiley, 1997; 266-282.
10. Gillberg C, Ehlers S, Schaumann H, Jakobson G, Dahlgren SO, Lindbolm R, Bagenholm A, Tjuus T, Blidner E. Autism under age 3 years: A clinical study of 28 cases referred for autistic symptoms in infancy. J Child Psychol Psychiatry 1990; 31: 921-934.
11. Ohta M, Nagai Y, Hara H, Sasaki M. Parental perception of behavioral symptoms in Japanese autistic children. J Autism Dev Disord 1987; 17: 549-563.
12. Baranek GT. Autism during infancy: A retrospective video analysis of sensory-motor and social behavior at 9-12 months of age. J Autism Dev Disord 1999; 29: 213-224.
13. Dahlgren SO, Gillberg C, Symptoms in the first two years of life. Euro Arch Psychiatry Neurol Sc 1989;238: 169-174.
14. Schopler E, Reichler RJ, Renner BR. The Childhood Autism Rating Scale . Los Angeles; Western Psychological Services,1988.
15. Alpern B, Boll T, Shearer M. Developmental Profile II (DP II). Los Angeles CA; Western Psychological Services.
16. Mundy P, Sigman M. Specifying the nature of the social impairment in autism. In G. Dawson, ed. Autism: Nature, Diagnosis and Treatment. New York; Guilford, 1989; 1-21.
17. Volkmar FR, Carter A, Sparrow S, Cicchetti DV. Quantifying social development in autism. J Am Acad Child Adolesc Psychiatry 1993; 32: 627-632.
18. Freeman BJ, Ritvo ER, Yokota A, Childs J, Pollard J. WISC-R and Vineland Adaptive Behavior scale scores in autistic children. J Am Acad Child Adolesc Psychiatry 1988; 27: 428-429.
19. Freeman BJ, Rahbar B, Ritvo ER, Bice TL, Yokota A, Ritvo. The stability of cognitive and behavioral parameters in autism: A twelve- year prospective study. J Am Acad Child Psychiatry 1991; 30: 479-482.
20. Venter A, Lord C, Schopler E. A follow-up study of high functioning autistic children. J Child Psychol Psychiatry 1992; 33: 489-507.
21. Stone WL, Ousley OY, Hepburn SL, Hogan KL, Brown CS. Patterns of adaptive behavior in very young children with autism. Am J Ment Retard 1999; 104: 187-199.
22. Loveland KA, Kelly ML. Development of adaptive behavior in adolescents and young adults with autism and Down syndrome. Am J Ment Retard 1988; 93: 84-92.
23. Klin A, Volkmar FR, Sparrow S. Autistic social dysfunction: Some limitations of the theory of mind hypothesis. J Child Psychol Psychiatry Allied Disc 1992; 33: 861-876.(Malhi Prahbhjot, Singhi P)