Early Detection of Autism Spectrum Disorders interest may not present in young children with ASDs. These patterns of behaviours vary among young individuals with ASDs. Therefore, diagnosis of ASDs in very young childre should focus on social skills and language skills deficits rather than stereotypies and repetitive behaviours. 4. Screening tools for ASDs The American Academy of Pediatrics(AAP)recommends ASDs screening in children age 18 and 24 months as part of developmental surveillance during regular health visits ohnson Myers, 2007). There are many valuable screening tools designed, such as the Checklist for Autism in Toddlers(CHAT)(Baron-Cohen et al., 1992; Baron-Cohen et al., 1996), the Modified Checklist for Autism in Toddlers(M-CHAT)(Kleinman et al, 2008; Robins et al 2001), the Screening Test for Autism in Two-Year-Olds(STAT)(Stone et al, 2000)and the Pervasive Developmental Disorders Screening Test-II(PDDST-II)(Siegel, 2004). All of these tools, except the STAT, are designed as first-level screens(i.e. the tools are administered to all children to differentiate children who are at risk of ASDs from the general population) Baron-Cohen et al conducted a study using the CHaT to administer in a primary health care setting to identify 18-month-old children at risk of ASDs. The study included both direct observation and a questionnaire for parents. The CHAT focuses on 3 key items which are gaze monitoring, protodeclarative pointing and pretend play. Findings from the study in the general population demonstrated that, the CHAT had a specificity of 98%-100% and sensitivity of 18%-38%(Baird et al., 2000; Baron-Cohen et al., 1992; Baron-Cohen et al, 1996; Scambler et al, 2001). Attempts to improve sensitivity by modifying the cut-off criteria resulted in decrease in positive predictive value(from 75% to 5%). Overall, use of the CHAT as a screening tool remains problematic owing to low sensitivity( Bryson et al., 2003) The M-CHAT is a screening tool for children 16 to 48 months and was developed to improve prediction of the CHAT In the M-CHAT, there is no observation component, but includes a wider range of signs and symptoms of ASDs. This parental questionnaire consists of 23(yes- no)items. Children who fail any three items or two critical items are considered to be at risk for ASDs. Items that were found to be the best predictors for ASDs were protodeclarative pointing, response to name, interest in peers, bringing things to show parents, following a point, and imitation. The reported sensitivity and specificity of the M-CHAT were around 89%and 93%, respectively(Dumont-Mathieu &z Fein, 2005). However, the positive predictive value(PPv)was low(0. 11+0.05)when it was used alone as a screen for ASDs in a community-based sample. The follow-up interview was reported to be able to significantly increase the PPV(Kleinman et al. 2008 ). Overall, the M-CHAT showed higher sensitivity than the Chat and is possibly useful in identifying children in need of further assessments, but should not be used as a screen to exclude the possibility of ASDs(Eaves et al., 2006; Barbaro Dissanayake, 2009) The STAT is a second-level screen(that is, the tool is used to differentiate children who are at risk of ASDs from those at risk of other developmental disorders). It was designed to be used in children aged 2-3 years. The STAT includes 12 pass/fail items and is administered in a play-like setting in order to observe social-communicative behaviours. The test lasts pproximately 20 minutes to complete. The estimated sensitivity and specificity were 95% and 73%, respectively(Stone et al., 2008). However, increased validity in larger studies and
Early Detection of Autism Spectrum Disorders 7 interest may not present in young children with ASDs. These patterns of behaviours vary among young individuals with ASDs. Therefore, diagnosis of ASDs in very young children should focus on social skills and language skills deficits rather than stereotypies and repetitive behaviours. 4. Screening tools for ASDs The American Academy of Pediatrics (AAP) recommends ASDs screening in children age 18 and 24 months as part of developmental surveillance during regular health visits (Johnson & Myers, 2007). There are many valuable screening tools designed, such as the Checklist for Autism in Toddlers (CHAT) (Baron-Cohen et al., 1992; Baron-Cohen et al., 1996), the Modified Checklist for Autism in Toddlers (M-CHAT) (Kleinman et al., 2008; Robins et al., 2001), the Screening Test for Autism in Two-Year-Olds (STAT) (Stone et al., 2000) and the Pervasive Developmental Disorders Screening Test-II (PDDST-II) (Siegel, 2004). All of these tools, except the STAT, are designed as first-level screens (i.e. the tools are administered to all children to differentiate children who are at risk of ASDs from the general population). Baron-Cohen et al conducted a study using the CHAT to administer in a primary health care setting to identify 18-month-old children at risk of ASDs. The study included both direct observation and a questionnaire for parents. The CHAT focuses on 3 key items which are gaze monitoring, protodeclarative pointing and pretend play. Findings from the study in the general population demonstrated that, the CHAT had a specificity of 98%-100% and a sensitivity of 18%-38% (Baird et al., 2000; Baron-Cohen et al., 1992; Baron-Cohen et al., 1996; Scambler et al., 2001). Attempts to improve sensitivity by modifying the cut-off criteria resulted in decrease in positive predictive value (from 75% to 5%). Overall, use of the CHAT as a screening tool remains problematic owing to low sensitivity (Bryson et al., 2003). The M-CHAT is a screening tool for children 16 to 48 months and was developed to improve prediction of the CHAT. In the M-CHAT, there is no observation component, but includes a wider range of signs and symptoms of ASDs. This parental questionnaire consists of 23 (yesno) items. Children who fail any three items or two critical items are considered to be at risk for ASDs. Items that were found to be the best predictors for ASDs were protodeclarative pointing, response to name, interest in peers, bringing things to show parents, following a point, and imitation. The reported sensitivity and specificity of the M-CHAT were around 89% and 93%, respectively (Dumont-Mathieu & Fein, 2005). However, the positive predictive value (PPV) was low (0.11±0.05) when it was used alone as a screen for ASDs in a community-based sample. The follow-up interview was reported to be able to significantly increase the PPV (Kleinman et al., 2008). Overall, the M-CHAT showed higher sensitivity than the CHAT and is possibly useful in identifying children in need of further assessments, but should not be used as a screen to exclude the possibility of ASDs (Eaves et al., 2006; Barbaro & Dissanayake, 2009). The STAT is a second-level screen (that is, the tool is used to differentiate children who are at risk of ASDs from those at risk of other developmental disorders). It was designed to be used in children aged 2-3 years. The STAT includes 12 pass/fail items and is administered in a play-like setting in order to observe social-communicative behaviours. The test lasts approximately 20 minutes to complete. The estimated sensitivity and specificity were 95% and 73%, respectively (Stone et al., 2008). However, increased validity in larger studies and community-based samples are required
Autism Spectrum Disorders: The Role of Genetics in Diagnosis and Treatment The PDDST-Il has both a first and second level screen versions. It is a parental questionnaire that can be used with children under 6 years of age. To date, the clinical validity remains unclear because it has not yet been published in a peer-reviewed journal (volkmar et al 2005) 5. Diagnostic instrument for ASDs Currently, there are standardized instruments to facilitate diagnosis in ASDs. The Autism Diagnostic Interview -Revised(ADI-R)(Le Couteur et al., 2003; Lord et al., 1994)and the Autism Diagnostic Observation Schedule(ADOS)(Lord et al., 2000a)are well validated and currently their combination with clinical judgment based on the DSM-IV-TR criteria are considered as the"gold standard"for diagnosis of ASDs(Battaglia, 2007). However, these instruments should be used with caution in very young children or children with a mental age less than 24 months( Stone et al, 1999) The ADOs is the most widely used standardized semistructured assessment of communication, social interaction and play. The scenarios for interaction with the child are used in the ADOS and require a well-trained interviewer. The ADOS consists of 4 modules devised for individuals with varying developmental and language level. Each module lasts approximately 40 minutes. The ADOs provides an algorithm to differentiate between autism, ASD and not ASD. Alpha coefficients are 0.86-0.91 for the social domain(across modules), 0.74-0.84 for communication, and 0.63-0.65 for repetitive behaviours(modules and 2)(Lord et al., 2000a). In younger children, especially younger than 15 months of ag the sensitivity is excellent, the specificity is doubtful( Chawarska et al, 2007; Lord et al 2000b; Risi et al., 2006). Luyster et al developed the toddler version of the ADOS(ADOS- Toddler Module or ADOS-T)which can be used for children under 30 months of age who have non-verbal mental ages of at least 12 months. The ADOS-T has acceptable internal ncy and excellent inter-rater and test-retest reliability(Luyster et al., 2009) However, larger samples of children and long follow-up studies need further replication. The ADI-R is a standardized parental interview conducted by a trained interviewer. The interview covers the past developmental history and current functioning of individuals. The tool consists of 111 questions and takes about 2-3 hours. The ADI-R is designed to use in children about 4-5 years old. The ADI-R provides an algorithm to differentiate between autism and not autism. The ADI-R is reliable and valid. The inter-rater reliability on individual algorithm items ranges from 0.63 to 0.89.The internal consistency (alph oefficients) is 0.69-0.95(Lord et al., 1994). However, the time needed for administration precludes its use in clinical settings. Moreover, further study is needed for identifying ASDs in preschool children(Le Couteur et al, 2008; Mazefsky Oswald, 2006; Risi et al., 2006) The Developmental, Dimensional and Diagnostic Interview ( 3Di is a new structured computerized interview for the diagnosis of ASDs and extends to co-morbid disorders There are total 266 questions on autistic spectrum disorders(ASD)symptoms and 53 questions for an abbreviated interview. The questions in the interview are clustered according to domains of function: reciprocal social interaction skills, social expressiveness, use of language and other social communication skills, use of gesture and non-verbal play, and repetitive/stereotyped behaviours and routines. To reduce a risk of respondent bias, breaking down complex questions and scattering their components throughout the interview were done. A study reported that test-retest and inter-rater reliabilities were
8 Autism Spectrum Disorders: The Role of Genetics in Diagnosis and Treatment The PDDST-II has both a first and second level screen versions. It is a parental questionnaire that can be used with children under 6 years of age. To date, the clinical validity remains unclear because it has not yet been published in a peer-reviewed journal (Volkmar et al., 2005). 5. Diagnostic instrument for ASDs Currently, there are standardized instruments to facilitate diagnosis in ASDs. The Autism Diagnostic Interview – Revised (ADI-R) (Le Couteur et al., 2003; Lord et al., 1994) and the Autism Diagnostic Observation Schedule (ADOS) (Lord et al., 2000a) are well validated and currently their combination with clinical judgment based on the DSM-IV-TR criteria are considered as the “gold standard” for diagnosis of ASDs (Battaglia, 2007). However, these instruments should be used with caution in very young children or children with a mental age less than 24 months (Stone et al., 1999). The ADOS is the most widely used standardized semistructured assessment of communication, social interaction and play. The scenarios for interaction with the child are used in the ADOS and require a well-trained interviewer. The ADOS consists of 4 modules devised for individuals with varying developmental and language level. Each module lasts approximately 40 minutes. The ADOS provides an algorithm to differentiate between autism, ASD and not ASD. Alpha coefficients are 0.86-0.91 for the social domain (across modules), 0.74-0.84 for communication, and 0.63-0.65 for repetitive behaviours (modules 1 and 2) (Lord et al., 2000a). In younger children, especially younger than 15 months of age, the sensitivity is excellent, the specificity is doubtful (Chawarska et al., 2007; Lord et al., 2000b; Risi et al., 2006). Luyster et al developed the toddler version of the ADOS (ADOSToddler Module or ADOS-T) which can be used for children under 30 months of age who have non-verbal mental ages of at least 12 months. The ADOS-T has acceptable internal consistency and excellent inter-rater and test-retest reliability (Luyster et al., 2009). However, larger samples of children and long follow-up studies need further replication. The ADI-R is a standardized parental interview conducted by a trained interviewer. The interview covers the past developmental history and current functioning of individuals. The tool consists of 111 questions and takes about 2-3 hours. The ADI-R is designed to use in children about 4-5 years old. The ADI-R provides an algorithm to differentiate between autism and not autism. The ADI-R is reliable and valid. The inter-rater reliability on individual algorithm items ranges from 0.63 to 0.89.The internal consistency (alpha coefficients) is 0.69-0.95 (Lord et al., 1994). However, the time needed for administration precludes its use in clinical settings. Moreover, further study is needed for identifying ASDs in preschool children (Le Couteur et al., 2008; Mazefsky & Oswald, 2006; Risi et al., 2006). The Developmental, Dimensional and Diagnostic Interview (3Di) is a new structured computerized interview for the diagnosis of ASDs and extends to co-morbid disorders. There are total 266 questions on autistic spectrum disorders (ASD) symptoms and 53 questions for an abbreviated interview. The questions in the interview are clustered according to domains of function: reciprocal social interaction skills, social expressiveness, use of language and other social communication skills, use of gesture and non-verbal play, and repetitive/stereotyped behaviours and routines. To reduce a risk of respondent bias, breaking down complex questions and scattering their components throughout the interview were done. A study reported that test-retest and inter-rater reliabilities were
Early Detection of Autism Spectrum Disorders excellent. The sensitivity and specificity were estimated about 100% and 97%, respectively Both the original 3di and the short version demonstrated high agreement with the ADI-R (Santosh et al., 2009; Skuse et al., 2004). Moreover, the short version takes less time to erform compared with the ADI-R. However, the study was limited to mild cases of ASDs, and so far limited numbers of young children have been tested The Autism Observation Scale for Infants(AOsD)(Bryson et al., 2008)is a diagnostic instrument that was developed for infants aged 6-18 months. The instrument consists of 18- item direct observational measure. Various activities were developed to assess the infants ours These target behaviours are disengagement; coordination of eye gaze and action; imitation; early social-affective and communicative behaviours; behavioural reactivity; and various sensory-motor behaviours The inter-rater reliability ranges from 0.68 to 0.94 12 and 18 months. Test-retest reliability is acceptable. The AOSI takes approximately 20 minutes to administer. Although, the AOSI is a useful diagnostic instrument for young children, it is not yet proposed to b In brief, although there have been a number of screening and diagnostic instruments to facilitate ASDs diagnosis, a comprehensive evaluation for suspected ASDs should be performed Such evaluations include a developmental history, parental interview, thorough physical examinations, clinical observations, developmental evaluations, assessment of the strengths and weaknesses of the child, assessment of family functioning, administration of standardized diagnostic instruments that operationalize the DSM criteria, and measures of cognitive and adaptive functions. Such comprehensive approaches together with early detection can lead to early intervention and result in improvement of the long-term functioning of children with ASDs 6. Summary Early detection of ASDs provides the best opportunity for early intervention, which results in significantly improved outcomes for children with ASDs. Awareness of the importance of early diagnosis and treatment has increased attention on knowledge of the very early manifestations of ASDs. Early manifestations include abnormalities in social interaction, communication and behaviours. Firstly, regarding social interaction, a lack of eye contact, orienting to name call, imitation, joint attention and limited responding to reciprocal play skills are the markers that should be of concern. Secondly, in the area of communication, an lack or delay of communication skills including verbal and non-verbal communication are indicative signs of ASDs. Lastly, the abnormal or unusual behaviours(i.e. repetitive and stereotypic behaviours, restrictive interests, preoccupied with sameness/ routine and sensory abnormalitiescan be apparent in young children, however, these behaviours may ot serve as important predictors of ASDs as the social and communication impairment Although, there are screening instruments to help identify children with ASDs in community-based samples, there is no screening instrument that provides adequate sensitivity and specificity for universal screening( Barbaro Dissanayake, 2009). According to standardized diagnostic instruments, there have been many studies showing that the ADI-R and the ADOs have been well validated and are the instruments to accurately diagnose ASDs as early as 2 years. The combination of the ADOS and the ADI-R in conjunction with clinical diagnosis based on the DSM-IV-TR are recommended whe
Early Detection of Autism Spectrum Disorders 9 excellent. The sensitivity and specificity were estimated about 100% and 97%, respectively. Both the original 3di and the short version demonstrated high agreement with the ADI-R (Santosh et al., 2009; Skuse et al., 2004). Moreover, the short version takes less time to perform compared with the ADI-R. However, the study was limited to mild cases of ASDs; and so far limited numbers of young children have been tested. The Autism Observation Scale for Infants (AOSI) (Bryson et al., 2008) is a diagnostic instrument that was developed for infants aged 6-18 months. The instrument consists of 18- item direct observational measure. Various activities were developed to assess the infant’s target behaviours. These target behaviours are visual tracking and attentional disengagement; coordination of eye gaze and action; imitation; early social-affective and communicative behaviours; behavioural reactivity; and various sensory-motor behaviours. The inter-rater reliability ranges from 0.68 to 0.94 at 6, 12 and 18 months. Test-retest reliability is acceptable. The AOSI takes approximately 20 minutes to administer. Although, the AOSI is a useful diagnostic instrument for young children, it is not yet proposed to be used. In brief, although there have been a number of screening and diagnostic instruments to facilitate ASDs diagnosis, a comprehensive evaluation for suspected ASDs should be performed. Such evaluations include a developmental history, parental interview, thorough physical examinations, clinical observations, developmental evaluations, assessment of the strengths and weaknesses of the child, assessment of family functioning, administration of standardized diagnostic instruments that operationalize the DSM criteria, and measures of cognitive and adaptive functions. Such comprehensive approaches together with early detection can lead to early intervention and result in improvement of the long-term functioning of children with ASDs. 6. Summary Early detection of ASDs provides the best opportunity for early intervention, which results in significantly improved outcomes for children with ASDs. Awareness of the importance of early diagnosis and treatment has increased attention on knowledge of the very early manifestations of ASDs. Early manifestations include abnormalities in social interaction, communication and behaviours. Firstly, regarding social interaction, a lack of eye contact, orienting to name call, imitation, joint attention and limited responding to reciprocal play skills are the markers that should be of concern. Secondly, in the area of communication, any lack or delay of communication skills including verbal and non-verbal communication are indicative signs of ASDs. Lastly, the abnormal or unusual behaviours (i.e. repetitive and stereotypic behaviours, restrictive interests, preoccupied with sameness/ routine and sensory abnormalities) can be apparent in young children, however, these behaviours may not serve as important predictors of ASDs as the social and communication impairments. Although, there are screening instruments to help identify children with ASDs in community-based samples, there is no screening instrument that provides adequate sensitivity and specificity for universal screening (Barbaro & Dissanayake, 2009). According to standardized diagnostic instruments, there have been many studies showing that the ADI-R and the ADOS have been well validated and are the instruments to accurately diagnose ASDs as early as 2 years. The combination of the ADOS and the ADI-R in conjunction with clinical diagnosis based on the DSM-IV-TR are recommended when
Autism Spectrum Disorders: The Role of Genetics in Diagnosis and Treatment gnosing very young children with ASDs. In clinical practice where diagnos instruments are not applicable, developmental surveillance with proper guidance is a recommended approach. Further prospective studies in young children should b conducted to provide evidence-based diagnosis for young children, especially under the age of two. Those developing research offer hope for better outcomes for children with ASDs 7. Acknowledgments We are very grateful to Dr. Suebwong Chuthapisith and Dr. Unchalee Lodin who proofrea this article 8. References American Psychiatric Association. (2000). Diagnostic and Statistical Manual of mental Disorders, Fourth Edition, Text Revision(DSM-IV-TR). Washington DC: American Psychiatric Publishing, Inc. Baird, G. Charman, T. Baron-Cohen, S. Cox, A Swettenham, J; Wheelwright, S. &z Drew A(2000). A screening instrument for autism at 18 months of age: a 6-year follow up study. J An. Acad. Child Adolesc. Psychiatry 39(6): 694-702 and social behaviors at 9-12 months of age. Autism Dev Disord. 29(3): 213- motor Baranek, GT.(1999). Autism during infancy: a retrospective video analysis of sensory Barbaro, J. Dissanayake, C.(2009). Autism spectrum disorders in infancy and toddlerhood: a review of the evidence on early signs, early identification tools, and early diagnosis. J Dev. Behav. Pediatr. 30(5): 4417-59 Baron-Cohen, S. Allen, J. Gilberg, C(1992) Can autism be detected at 18 months? The needle, the haystack, and the CHAT. Br. Psychiatry 161: 839-43 aron-Cohen, S; Cox, A Baird, G. Swettenham, J- Nightingale, N. Morgan, K. Drew, A & Charman, T.(1996). Psychological markers in the detection of autism in infancy in a large population. Br J Psychiatry 168(2): 1586 Battaglia, A.(2007). On the selection of patients with developmental delay/mental retardation and autism spectrum disorders for genetic studies. Am. J Med Genet. A 143A(8):78990 Bryson, SE. Zwaigenbaum, L. McDermott, C. Rombough, V& Brian, J. (2008). The Autism Observation Scale for Infants: Scale development and reliability data. J Autism Dev Disord. 38: 731-38 Bryson, SE. Rogers, s]. Fombonne, E.(2003). Autism spectrum disorders: early detection, intervention, education, and psychopharmacological management. Can J Psychiat Charman, T(2003). Why is joint attention a pivotal skill in autism? Philos. Trans. R. Soc. Lond BBil.Sci.358(1430)315-24 Charman, T& Baird, G(2002). Practitioner review: Diagnosis of autism spectrum disorder in 2-and 3-year-old children. Child Psychol Psychiatry 43 (3): 289-305 Chawarska, K Klin, A Paul,R& volkmar, F.(2007). Autism spectrum disorder in the second year: stability and change in syndrome expression. Child Psychol Psychiatry 48(2:128-38
10 Autism Spectrum Disorders: The Role of Genetics in Diagnosis and Treatment diagnosing very young children with ASDs. In clinical practice where diagnostic instruments are not applicable, developmental surveillance with proper guidance is a recommended approach. Further prospective studies in young children should be conducted to provide evidence-based diagnosis for young children, especially under the age of two. Those developing research offer hope for better outcomes for children with ASDs. 7. Acknowledgments We are very grateful to Dr. Suebwong Chuthapisith and Dr. Unchalee Lodin who proofread this article. 8. References American Psychiatric Association. (2000). Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR). Washington DC: American Psychiatric Publishing, Inc. Baird, G.; Charman, T.; Baron-Cohen, S.; Cox, A.; Swettenham, J.; Wheelwright, S. & Drew, A. (2000). A screening instrument for autism at 18 months of age: a 6-year followup study. J Am. Acad. Child Adolesc. Psychiatry 39(6):694-702 Baranek, GT. (1999). Autism during infancy: a retrospective video analysis of sensory-motor and social behaviors at 9-12 months of age. J Autism Dev. Disord. 29(3):213-24 Barbaro, J. & Dissanayake, C. (2009). Autism spectrum disorders in infancy and toddlerhood: a review of the evidence on early signs, early identification tools, and early diagnosis. J Dev. Behav. Pediatr. 30(5):447-59 Baron-Cohen, S.; Allen, J. & Gillberg, C. (1992). Can autism be detected at 18 months? The needle, the haystack, and the CHAT. Br. J Psychiatry 161:839-43 Baron-Cohen, S.; Cox, A.; Baird, G.; Swettenham, J.; Nightingale, N.; Morgan, K.; Drew, A. & Charman, T. (1996). Psychological markers in the detection of autism in infancy in a large population. Br. J Psychiatry 168(2):158-63 Battaglia, A. (2007). On the selection of patients with developmental delay/mental retardation and autism spectrum disorders for genetic studies. Am. J Med Genet. A 143A(8):789-90 Bryson, SE.; Zwaigenbaum, L.; McDermott, C.; Rombough, V. & Brian, J. (2008). The Autism Observation Scale for Infants: Scale development and reliability data. J Autism Dev. Disord. 38: 731-38 Bryson, SE.; Rogers, SJ. & Fombonne, E. (2003). Autism spectrum disorders: early detection, intervention, education, and psychopharmacological management. Can. J Psychiatry 48(8):506-16 Charman, T. (2003). Why is joint attention a pivotal skill in autism? Philos. Trans. R. Soc. Lond B Biol. Sci. 358(1430):315-24 Charman, T. & Baird, G. (2002). Practitioner review: Diagnosis of autism spectrum disorder in 2- and 3-year-old children. J Child Psychol. Psychiatry 43(3):289-305 Chawarska, K.; Klin, A.; Paul, R. & Volkmar, F. (2007). Autism spectrum disorder in the second year: stability and change in syndrome expression. J Child Psychol. Psychiatry 48(2):128-38
Early Detection of Autism Spectrum Disorders Cox, A Klein, K i Charman, T; Baird, G. Baron-Cohen, S. Swettenham, J- Drew, A. Wheelwright, S( 1999). Autism spectrum disorders at 20 and 42 months of age: stability of clinical and ADI-R diagnosis. Child Psychol Psychiatry 40(5): 719-32 Dawson, G. Munson, J. Estes, A Osterling, J. McPartland, J Toth, K. Carver, L Abbott, R.(2002). Neurocognitive function and joint attention ability in young children with autism spectrum disorder versus developmental delay. Child Dev De Giacomo A, Fombonne E. 1998. Parental recognition of developmental abnormalities in autism. Eur. Child Adolesc Psychiatry 7(3): 131-6 Dumont-Mathieu, T. Fein, D.(2005). Screening for autism in young children: The Modified Checklist for Autism in Toddlers(M-CHAT) and other measures. Ment Retard. Dev Disabil Res. Rev. 11(3): 253-62 Eaves, LC. Wingert, H. Ho, HH. (2006). Screening for autism: agreement with diagnosi Autism10(3):22942 Tonge, B].(2001). Are there early features of autism in infants and preschool children? )Paediatr. Child Health 37(3): 221-6 Johnson, CP(2008). Recognition of autism before age 2 years. Pediatr. Rev. 29(3): 86-96 Johnson, CP. Myers, SM.(2007). Identification and evaluation of children with autism spectrum disorders. Pediatrics 120(5): 1183-215 Kleinman, JM. Robins, DL Ventola, PE. Pandey, J Boorstein, HC. Esser, EL Wilson, LB Rosenthal, MA, Sutera, S; Verbalis, AD. Barton, M. Hodgson, S; Green, J Dumont-Mathieu, T, Volkmar, F; Chawarska, K. Klin, A& Fein, D(2008). The modified checklist for autism in toddlers: a follow-up study investigating the early detection of autism spectrum disorders. J Autism DeD. Disord. 38 (5): 827-39 Le Couteur, A Haden, G. Hammal, D. &z McConachie, H.(2008). Diagnosing autism spectrum disorders in pre-school children using two standardised assessment instruments: the ADI-R and the ADOS. J Autism Dev. Disord. 38(2): 362-72 Le Couteur, A Lord, C. rutter, M.(2003). The Autism Diagnostic Interview-Revised(ADI-R) Los Angeles, CA: Western Psychological Services. Lord, C; Risi, S; Lambrecht, L; Cook, EH Jr; Leventhal, BL; DiLavore, PC; Pickles, A.& Rutter, M.(2000a). The autism diagnostic observation schedule-generic: a standard measure of social and communication deficits associated with the spectrum of Autism Dev Di ord, C. Risi, S.& Wetherby, AM, et al.(2000b). Diagnosis of autism spectrum disorders in young children. In Autism spectrum disorders: a transactional development perspective, ed. Wetherby AM, Prizant BM,11-30 pp. Baltimore: Paul H Brookes Publishing. 11-30 pp Lord, C i Rutter, M. Le Couteur, A.(1994). Autism Diagnostic Interview-Revised:a revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. Autism Dev Disord. 24(5): 659-85 Lord, C Shulman, C& Dilavore, P(2004). Regression and word loss in autistic spectrur disorders. Child Psychol Psychiatry 45(5): 936-55 Luyster, R. Gotham, K. Guthrie, W, Coffing, M. Petrak, R. Pierce, K. Bishop, S. Esler, A Hus, V; Oti, R. Richler, J. Risi, S.& Lord, C.(2009). The Autism Diagnosti
Early Detection of Autism Spectrum Disorders 11 Cox, A.; Klein, K.; Charman, T.; Baird, G.; Baron-Cohen, S.; Swettenham, J.; Drew, A. & Wheelwright, S. (1999). Autism spectrum disorders at 20 and 42 months of age: stability of clinical and ADI-R diagnosis. J Child Psychol. Psychiatry 40(5):719-32 Dawson, G.; Munson, J.; Estes, A.; Osterling, J.; McPartland, J.; Toth, K.; Carver, L. & Abbott, R. (2002). Neurocognitive function and joint attention ability in young children with autism spectrum disorder versus developmental delay. Child Dev. 73(2):345-58 De Giacomo A, Fombonne E. 1998. Parental recognition of developmental abnormalities in autism. Eur. Child Adolesc. Psychiatry 7(3):131-6 Dumont-Mathieu, T. & Fein, D. (2005). Screening for autism in young children: The Modified Checklist for Autism in Toddlers (M-CHAT) and other measures. Ment. Retard. Dev. Disabil. Res. Rev. 11(3):253-62 Eaves, LC.; Wingert, H. & Ho, HH. (2006). Screening for autism: agreement with diagnosis. Autism 10(3):229-42 Gray, KM. & Tonge, BJ. (2001). Are there early features of autism in infants and preschool children? J Paediatr. Child Health 37(3):221-6 Johnson, CP. (2008). Recognition of autism before age 2 years. Pediatr. Rev. 29(3):86-96 Johnson, CP. & Myers, SM. (2007). Identification and evaluation of children with autism spectrum disorders. Pediatrics 120(5):1183-215 Kleinman, JM.; Robins, DL.; Ventola, PE.; Pandey, J.; Boorstein, HC.; Esser, EL.; Wilson, LB.; Rosenthal, MA.; Sutera, S.; Verbalis, AD.; Barton, M.; Hodgson, S.; Green, J.; Dumont-Mathieu, T.; Volkmar, F.; Chawarska, K.; Klin, A. & Fein, D. (2008). The modified checklist for autism in toddlers: a follow-up study investigating the early detection of autism spectrum disorders. J Autism Dev. Disord. 38(5):827-39 Le Couteur, A.; Haden, G.; Hammal, D. & McConachie, H. (2008). Diagnosing autism spectrum disorders in pre-school children using two standardised assessment instruments: the ADI-R and the ADOS. J Autism Dev. Disord. 38(2):362-72 Le Couteur, A.; Lord, C. & Rutter, M. (2003). The Autism Diagnostic Interview-Revised (ADI-R). Los Angeles, CA: Western Psychological Services. Lord, C.; Risi, S.; Lambrecht, L.; Cook, EH Jr.; Leventhal, BL.; DiLavore, PC.; Pickles, A. & Rutter, M. (2000a). The autism diagnostic observation schedule-generic: a standard measure of social and communication deficits associated with the spectrum of autism. J. Autism Dev. Disord. 30(3):205-23 Lord, C.; Risi, S. & Wetherby, AM., et al. (2000b). Diagnosis of autism spectrum disorders in young children. In Autism spectrum disorders: a transactional development perspective, ed. Wetherby AM, Prizant BM,11-30 pp. Baltimore: Paul H Brookes Publishing. 11-30 pp. Lord, C.; Rutter, M. & Le Couteur, A. (1994). Autism Diagnostic Interview-Revised: a revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. J Autism Dev. Disord. 24(5):659-85 Lord, C.; Shulman, C. & DiLavore, P. (2004). Regression and word loss in autistic spectrum disorders. J Child Psychol. Psychiatry 45(5):936-55 Luyster, R.; Gotham, K.; Guthrie, W.; Coffing, M.; Petrak, R.; Pierce, K.; Bishop, S.; Esler, A.; Hus, V.; Oti, R.; Richler, J.; Risi, S. & Lord, C. (2009). The Autism Diagnostic