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Biomedical subjects

L Waterhouse

Publications and source records attributed to L Waterhouse.

At least 19 recordsLinked to original sources
PubMed2001

Oxytocin and autistic disorder: alterations in peptide forms.

BACKGROUND: Oxytocin (OT) is synthesized as a prohormone that is sequentially processed to peptides. These peptides are the bioactive amidated form (OT) and the C-terminal extended peptides, OT-Gly, OT-Gly-Lys and OT-Gly-Lys-Arg, which are designated together as OT-X. As an extension of our previous study finding decreased plasma OT in autism, studies were conducted to determine whether there were changes in OT peptide forms in autistic children. METHODS: Twenty eight male subjects (97 +/- 20 months; range, 70-139 months), diagnosed with DSM-IV autistic disorder through observation and semi-structured interview, were compared with 31 age-matched nonpsychiatric control subjects (106 +/- 22 months; range, 74-140 months). Using OT antisera with different specificity for the peptide forms, we measured plasma OT and OT-X in each group. RESULTS: T tests showed that there was a decrease in plasma OT (t = 4.4, p <.0001), an increase in OT-X (t = 2.3, p <.03) and an increase in the ratio of OT-X/OT (t = 4.5, p <.0001) in the autistic sample, compared with control subjects. CONCLUSIONS: The results suggest that children with autistic disorder show alterations in the endocrine OT system. Deficits in OT peptide processing in children with autism may be important in the development of this syndrome.

Adolescent↗
PubMed2001

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

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.

Autistic Disorder↗
PubMed2001

Predictors and correlates of adaptive functioning in children with developmental disorders.

Autism is a developmental disorder marked by impairments in socialization, communication, and perseverative behavior and is associated with cognitive impairment and deficits in adaptive functioning. Research has consistently demonstrated that children with autism have deficits in adaptive functioning more severe than their cognitive deficits. This study investigates the correlates and predictors of adaptive functioning as measured by the Vineland Adaptive Behavior Scales in high- and low-functioning children with autism and their age and nonverbal IQ matched controls. Thirty-five 9-year-old children with high-functioning autism (HAD) were compared with 31 age-matched children with developmental language disorder (DLD), and 40 9-year-old children with low-functioning autism (LAD) were compared with 17 age-matched children with low IQ on adaptive functioning, IQ, autistic symptomology, and tests of language and verbal memory. Results indicate that both groups with autism were significantly impaired compared to their matched controls on Socialization and Daily Living, but not Communication and that these impairments were more pronounced in the HAD group than in the LAD group. Adaptive behavior was strongly correlated with autistic symptomology only in the HAD group. Regression analyses indicated that IQ was strongly predictive of adaptive behavior in both low-functioning groups, but tests of language and verbal memory predicted adaptive behavior in the higher functioning groups. Results suggest that IQ may act as a limiting factor for lower functioning children but higher functioning children are impaired by specific deficits, including autistic symptomology and impaired language and verbal memory.

Adaptation, Psychological↗
PubMed2001

Executive functioning in high-functioning children with autism.

Executive functioning was investigated in 34 children (24 boys and 10 girls) with developmental language disorder (DLD) and 21 children (18 boys and 3 girls) with high-functioning autistic disorder (HAD) matched on Full Scale IQ, Nonverbal IQ, age (mean age 9 year, 1 month), and SES. The DLD group had a Verbal IQ that was 10 points higher than the HAD group. These children were given the Wisconsin Card Sorting Test (WCST), the Mazes subtest from the WISC-R, the Underlining test, and the Rapid Automatized Naming test. In addition, these children were given the Vineland Scales of Adaptive Functioning and the Wing Diagnostic Symptom Checklist in order to assess severity of autistic symptomatology. Results indicated that the only significant difference between the two groups on the cognitive tasks was perseverative errors on the WCST; there was no significant difference on total number of categories achieved or total number of errors on the WCST or on the other executive function measures. There was also significant overlap in the scores between the two groups and the difference in perseverative errors was no longer significant when Verbal IQ was partialled out. Executive functioning was strongly related to all IQ variables in the DLD group and particularly related to Verbal IQ in the HAD group. Although there was a relationship in the HAD group between executive functioning and adaptive functioning, as well as between executive functioning and autistic symptomatology, these relationships were generally no longer significant in the HAD group after the variance due to Verbal IQ was accounted for. The results are interpreted to indicate that although impaired executive functioning is a commonly associated feature of autism, it is not universal in autism and is unlikely to cause autistic behaviors or deficits in adaptive function.

Autistic Disorder↗
PubMed1999

Consistency in the ratings of behaviors of communicatively impaired autistic and non-autistic preschool children.

Typically, children with disabilities are evaluated clinically by a number of professionals with different backgrounds whose task is to provide a diagnosis and an intervention plan. This study was carried out to describe interrater agreement for pairs of independent observers rating with different instruments the behaviors of 505 communicatively impaired autistic and nonautistic preschool children. Observers were parents, teachers, neurologists, and psychiatrists. Parents and teachers responded to behavioral questionnaires, neurologists filled out the mental status part of a standardized neurologic evaluation, and psychiatrists an observational questionnaire. All four types of observers rated sociability, language, play, attention, stereotyped, and other aberrant behaviors. Agreement between pairs of raters was significant but moderate. Owing to range restriction with smaller numbers of subjects, agreement decreased for ratings of subsamples divided according to diagnosis, cognitive level, or age. There were some differences among observers' ratings of the severity of particular categories of behaviors, with physicians generally viewing the children as more severely impaired and teachers as least impaired. Interrater agreement was not enhanced when parents and teachers rated similarly worded behavioral items. Modest interrater agreement in this study, like agreement among disparate raters of children's behaviors in other studies, suggests that observers are sensitive to different aspects of behavior and that their ratings are more likely to be complementary than unreliable.

Autistic Disorder↗
PubMed1998

Plasma oxytocin levels in autistic children.

BACKGROUND: Social impairments are central to the syndrome of autism. The neuropeptide oxytocin (OT) has been implicated in the regulation of social behavior in animals but has not yet been examined in autistic subjects. METHODS: To determine whether autistic children have abnormalities in OT, midday plasma samples from 29 autistic and 30 age-matched normal children, all prepubertal, were analyzed by radioimmunoassay for levels of OT. RESULTS: Despite individual variability and overlapping group distributions, the autistic group had significantly lower plasma OT levels than the normal group. OT increased with age in the normal but not the autistic children. Elevated OT was associated with higher scores on social and developmental measures for the normal children, but was associated with lower scores for the autistic children. These relationships were strongest in a subset of autistic children identified as aloof. CONCLUSIONS: Although making inferences to central OT functioning from peripheral measurement is difficult, the data suggest that OT abnormalities may exist in autism, and that more direct investigation of central nervous system OT function is warranted.

Autistic Disorder↗
PubMed1998

The responses of autistic children to the distress of others.

The behavior of preschool children from five groups (developmental language disordered, high-functioning autistic, low-functioning autistic, mentally retarded, and normally developing) were coded in three situations: presentation of a nonsocial orienting stimulus (an unfamiliar noise) and two social situations involving simulated distress on the part of an adult with whom they were playing. Cognitive level was correlated with level of responsiveness to stimuli only for the two retarded groups (mentally retarded and low-functioning autistic). Girls showed more prosocial behavior than boys in both social situations, independent of diagnosis. The language-disordered children showed only mild and subtle social deficits. The low-functioning autistic children showed pronounced deficits in responding in all situations. The mentally retarded and high-functioning autistic children showed good awareness of all situations, but were moderately impaired in their ability to respond prosocially; they rarely initiated prosocial behavior, but did respond to specific prompts. The behavioral feature that marked both autistic groups, in contrast to all other groups, was a lack of social referencing; they did not tend to look toward an adult in the presence of an ambiguous and unfamiliar stimulus. Results are discussed in terms of variability between and among high- and low-functioning autistic children, and implications for the core deficits in autism.

Affect↗
PubMed1997

Delay versus deviance in autistic social behavior.

The pattern of acquisition of social, communication, and daily living skills was examined for autistic children, compared to retarded and normal controls, by quantifying intradomain scatter on the Vineland Adaptive Behavior Scales. Autistic children were matched to normal children and mentally retarded children on Vineland raw scores; group differences in scatter were examined for each domain of adaptive behavior. Autistic children had significantly more scatter on Communication and Socialization than both control groups. Item analyses showed that the autistic children had particular weaknesses on items reflecting attention to and pragmatic use of language, as well as play and reciprocal social interaction; the autistic children had particular strengths on items reflecting written language and rote language skills, and rule-governed social behavior. The number of items showing consistent group differences, however, was small, suggesting that although autistic development appears sequentially deviant and not merely delayed, individual autistic children derive their scatter from different items, and are a developmentally heterogeneous group.

Activities of Daily Living↗
PubMed1996

Diagnosis and classification in autism.

This study compared four systems for the diagnosis of autism (DSM-III, DSM-III-R, DSM-IV, and ICD-10) with two empirically derived taxa of autism, and with three social subgroups of autism (Aloof, Passive, and Active-but-Odd) in 194 preschool children with salient social impairment. There were significant behavior and IQ differences between autistic and other-PDD groups for all four diagnostic systems, and a significant association was found (a) for Taxon B, diagnoses of autism, and the Aloof subgroup, and (b) for Taxon A, other-PDD, and the Active-but-Odd subgroup. Findings offer support for two major overlapping continua within idiopathic Pervasive Developmental Disorder.

Algorithms↗
PubMed1996

Neurofunctional mechanisms in autism.

Behavioral impairments in autism are theorized to result from abnormal neuronal organization in brain development generating 4 systemically related neurofunctional impairments: (a) canalesthesia, wherein abnormal hippocampal system function "canalizes" sensory records, disrupting integration of information; (b) impaired assignment of the affective significance of stimuli, wherein abnormal amygdaloid system function disrupts affect association; (c) asociality, wherein impaired oxytocin system function flattens social bonding and affiliativeness; and (d) extended selective attention, wherein abnormal organization of temporal and parietal polysensory regions yields aberrant overprocessing of primary representations. This model proposes that complex human behaviors may be guided by multiple overlapping neural mechanisms.

Adolescent↗
PubMed1995

Social initiations by autistic children to adults and other children.

Social initiations made by autistic and verbal-matched retarded children were recorded in two naturalistic situations. Frequencies of initiation to adults did not differ between groups, but the retarded children initiated much more frequently to peers. Most interactions for both groups were positive, but the autistic children engaged in more ritualized, and the retarded children more playful, initiations. The autistic children monitored the social environment more when forced into proximity with peers, whereas the retarded children initiated more in the unstructured situation. Autistic initiation to peers was unrelated to severity of autism, but was related to cognitive skills, including vocabulary and comprehension of affect, whereas retarded children's initiations were unrelated to cognitive level. Results are discussed in terms of the differences between adults and children as social stimuli, prerequisite skills for initiation to peers, and the relationship between social cognition and social behavior. It is suggested that autistic and retarded children differ in the quantity of their initiations to peers, and the quality of their initiations to adults, and that initiations to peers may be a particularly useful index of social development in autistic children. Results confirm the need of autistic children for highly structured social environments, and suggest an important role for the remediation of specific cognitive skills such as comprehension of others' affects.

Adolescent↗
PubMed1992

Pervasive developmental disorders: from DSM-III to DSM-III-R.

The present paper provides a brief history of the development of the DSM-III-R (American Psychiatric Association [APA], 1987) section on Pervasive Developmental Disorders. It describes the process by which the contents of the text and criteria for Autistic Disorder and Pervasive Developmental Disorder Not Otherwise Specified were decided and gives the reasons for the changes from DSM-III (APA, 1980) categories and criteria. The paper concludes with a short discussion of critical diagnostic issues.

Autistic Disorder↗
PubMed1992

Comprehension of affect in context in children with pervasive developmental disorders.

Fifteen children with Pervasive Developmental Disorders (PDD) (mean age 12.7 years) were compared to mental age matched normal children on matching a context to its appropriate emotion. PDD children were slightly but significantly impaired on this task relative to a non-social task equated for difficulty. Both matching tasks were highly correlated with cognitive variables; the social matching task alone was correlated with social skill level, and neither task was correlated with ratings of social deviance. Results are discussed in terms of the demands of social cognitive tasks, the magnitude of social cognitive findings, control group selection and individual differences.

Affect↗