Autistic disorder versus other pervasive developmental disorders in young children: same or different?

Abstract

Eighteen preschool children diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders Third Edition Revised (DSM III-R) as having Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) were compared to 176 children with DSM III-R Autistic Disorder (AD), and to 311 non-autistic children with developmental language disorders (DLD) (N = 201) or low IQ (N = 110). All children were partitioned into "high" and "low" cognitive subgroups at a nonverbal IQ of 80. Within cognitive subgroups, the 18 PDD-NOS children did not differ significantly from either the DLD or the AD children in verbal and adaptive skills and obtained scores intermediate between those of these groups. The PDD-NOS did not differ from the AD children in maladaptive behaviors. Both the PDD-NOS and AD children had many more of these behaviors than the non-autistic comparison groups. Children in the "high" and "low" cognitive subgroups of AD, but not of PDD-NOS, differed substantially on most measures, with the children with lower cognitive scores significantly more impaired on all measures. Similarity of PDD-NOS children to AD children in maladaptive behaviors and an intermediate position between autistic and non-autistic groups on virtually all measures explains the difficulty clinicians encounter in classifying children with PDD and raises questions about the specificity of these diagnostic subtypes of the autistic spectrum.

Pervasive Developmental Disorder- not Otherwise Specified: Specifying and Differentiating

“…Thus, from a clinical standpoint, children whose PDD-NOS diagnosis was established before 36 months should be re-assessed at a later age (Rondeau et al, 2010). Similar to previous reports (Allen et al, 2001, deBruin et al, 2006, Matson, et al, 2007, Szatmari et al 2002, in our study (Karabekiroglu & Akbas, in press) mental retardation was significantly more prevalent in the autism than in the PDD-NOS or ADHD groups. Several investigators suggested that exploring the presence of mental retardation may be more useful in terms of planning treatment and predicting outcome than a classification based on symptom number alone (Szatmari et al, 2002).…”

“…It was concluded that based on intelligence scores, only PDD-NOS and ADHD emerged as distinct categories, whereas the combined diagnosis did not. Allen et al (2001) compared 18 preschool children with PDD-NOS to 176 children with autistic disorder and 311 non-autistic children with developmental language disorders (DLD) (N = 201) or low IQ (N = 110). The children with PDD-NOS did not differ significantly from either the children with autism or the children with DLD in verbal and adaptive skills.…”

“…The children with PDD-NOS did not differ significantly from either the children with autism or the children with DLD in verbal and adaptive skills. They suggested that the similarity of PDD-NOS children to autistic children in maladaptive behaviors and an intermediate position between autistic and DLD groups on virtually all measures helped to explain the difficulty clinicians encounter in classifying children with PDD-NOS (Allen et al, 2001). …”

“…Four criteria discriminated autism from PDD-NOS most effectively: children with autism more often demonstrated restricted patterns of interest, lacked varied makebelieve play, failed to use nonverbal behavior, and had an earlier age of onset. In another study (Allen et al, 2001), the PDD-NOS group (including both high-and low-functioning children) did not differ significantly from the autism or non-PDD groups on measures of language or adaptive functioning but did show less restricted stereotyped behaviors than the high-functioning autism group. In a very recent study (Snow & Lecavalier, 2011), authors examined the validity of PDD NOS by comparing it to autistic disorder (AD) and other developmental disorders (DD) on parent-reported behavior problems.…”

Maternal Immune Activation and Autism Spectrum Disorder: Interleukin-6 Signaling as a Key Mechanistic Pathway

“…These changes in clinical observations have led to the classification of autism as a spectrum disorder, autism spectrum disorder (ASD), which describes a group of developmental disorders characterized by impairments in reciprocal social interaction and verbal and nonverbal communication skills compounded by symptoms of restrictive and repetitive behaviors and/or stereotyped patterns of interest that are abnormal in their intensity or focus [4][5][6][7] . Included in this spectrum is 'classical' autism, which usually involves the stereotypical social isolation, impaired verbal communication and repetitive behaviors; Asperger syndrome, often described as a milder form of autism, lacking the components of intense repetitive behaviors and social withdrawal; and pervasive developmental disorder, which usually encompasses disorders that cannot otherwise be classified [2,[7][8][9] .…”