Jacques Thivierge

Quantifying Dimensions in Autism: A Factor-Analytic Study

OBJECTIVE The objective of this study was to determine whether the phenotypic variation in autism and the related pervasive developmental disorders (PDDs) is a unitary construct or whether it is composed of distinct dimensions of autistic symptoms and measures of level of functioning. METHOD One hundred twenty-nine children with autism and other forms of PDD from two samples with different inclusion criteria were assessed with the Vineland Adaptive Behavior Scales to measure level of functioning and the Autism Diagnostic Interview to measure severity of autistic behaviors. A factor analysis with varimax rotation was performed on each sample, separately and combined. RESULTS Two factors emerged; one representing autistic symptoms and another representing level of functioning. The factor structure was remarkably similar and robust to variations in ascertainment and inclusion criteria between the samples. The validity of the distinction was supported by differences between males and females on the symptom factor, but not on the level of functioning factor. IQ was modestly correlated with level of functioning, but not with symptoms. CONCLUSIONS The phenotypic variation seen in autism/PDD is composed of at least two different dimensions of autistic symptoms and level of functioning. The implications of this dimensional heterogeneity for research, classification, and clinical practice are discussed.

The New York Longitudinal Studies Model of Temperament: Gender Differences and Demographic Correlates in a French‐speaking Population

A random sample of 984 normal children from among all 6253 second graders of Quebec City was studied by means of a French translation of the Thomas, Chess and Korn Parent Temperament Questionnaire (PTQ). Both test-retest reliability and the effect of trained persons assisting parents in filling out the PTQ were assessed. A temperamental typology similar to the New York Longitudinal Studies easy-difficult profile was observed. Findings included significantly more boys in the extremely difficult group and very slight or absent association between socioeconomic class and temperament. Higher representation in difficult child category may be a factor in greater psychiatric risk for boys; this has preventative implications.

Brain-stem auditory evoked response (BAER): normative study in children and adults

The influences of age and sex on the BAER latency values are analysed in a non-clinical sample of adults and children. We found (1) that BAER values vary according to age and sex, but for the III-V interpeak latency (IPL); (2) that the age effect is more important than the sex effect on absolute latency (AL) II, III and V; (3) that there is a significant sex effect on the I-III IPL. Comparisons to other studies are made: we find differences but no contradiction. This is briefly discussed.

Empirical characteristics of the NYLS temperament in middle childhood: congruities and incongruities with other studies.

Recent literature highlights the importance of studying the empirical qualities of the different models of temperament developed to date. The present paper deals specifically with the NYLS definition of temperament. The research data, gathered on a random sample (N=647) from the Quebec City general population aged 8 and 12 years, do not replicate the main typology (similar to the NYLS ‘easy-difficult’ cluster) previously identified in younger random samples of our population nor that found in other Swedish or American samples. The implications of the findings in terms of temperament main typology as well as in terms of SES and sex differences are discussed in the context of the other studies utilizing the NYLS definition of temperament. Developmental and methodological considerations are derived from the congruities and incongruities observed in the results of the various studies.

DEPRESSION IN A 13-YEAR-OLD CHILD : A NEAR MISS

Parents completed the Index of Parental Attitudes (7) (a 25-item scale that measures the degree of contentment a parent has with his or her child) and the Disruptive Behavior Disorder Questionnaire (8) (a 20-item report based on questions from the DSM-IV [9]), which measures 4 types of behaviour disorders: impulsivity, hyperactivity, conduct disorder, and oppositional disorder. Additionally, the children had postgroup debriefing meetings with the group therapists during which they were asked open-ended questions relating to their experience in group.