Pierrette Boutin

6p24–22 Region and Major Psychoses in the Eastern Quebec Population

Recent reports of a linkage trend in 6p24-22 for schizophrenia (SZ), in different samples, were tempered by the concurrent evidence of negative reports in other samples. In the studies showing positive results, different definitions of affection and a wide spectrum of diagnoses were used. Our objectives were not only to test for linkage at 6p24-22 in the Eastern Quebec population, but also to test whether this putative vulnerability locus was either selectively linked to schizophrenia (SZ), or to bipolar disorder (BP), or to both major psychoses. Parametric and nonparametric linkage analyses with 12 microsatellite markers in 6p24-p22 were performed on a sample of 18 large multigenerational pedigrees (N = 354) either affected by SZ, or by BP, or equally affected by both major psychoses (i.e., mixed pedigrees). Three affection definitions were usually tested in our program: one on schizophrenia (SZ), one on bipolar disorder (BP), and one that comprised SZ and BP under the hypothesis of a susceptibility locus common to both in major psychoses (common locus, CL). The results of parametric analyses did not support a major gene hypothesis. However, in one large mixed pedigree (#151), we observed with the common locus phenotype (CL) lod scores of 2.49 and 2.15, respectively, at the D6S296 and D6S277 loci under a dominant model. Our data suggest the presence of a potential vulnerability locus at 6p24-22 that could be related to both schizophrenia and bipolar affective disorder. These results may be seen as congruent with former studies that used schizoaffective as well as schizophrenia diagnoses as entry criteria for the affected families, and used an affection definition that comprised affective psychoses as well as schizophrenia.

Shared Neurocognitive Dysfunctions in Young Offspring at Extreme Risk for Schizophrenia or Bipolar Disorder in Eastern Quebec Multigenerational Families

BACKGROUND Adult patients having schizophrenia (SZ) or bipolar disorder (BP) may have in common neurocognitive deficits. Former evidence suggests impairments in several neuropsychological functions in young offspring at genetic risk for SZ or BP. Moreover, a dose-response relation may exist between the degree of familial loading and cognitive impairments. This study examines the cognitive functioning of high-risk (HR) offspring of parents having schizophrenia (HRSZ) and high-risk offspring of parents having bipolar disorder (HRBP) descending from densely affected kindreds. METHODS The sample consisted of 45 young offspring (mean age of 17.3 years) born to a parent having SZ or BP descending from large multigenerational families of Eastern Québec that are densely affected by SZ or BP and followed up since 1989. The offspring were administered a lifetime best-estimate diagnostic procedure (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition [DSM-IV]) and an extensive standard neuropsychological battery. Raw scores were compared with age- and gender-matched controls. RESULTS The offspring displayed differences in memory and executive functions when compared with controls. Moderate to large effect sizes (Cohen d) ranging from 0.65 to 1.25 (for IQ and memory) were observed. Several of the cognitive dysfunctions were present in both HRSZ and HRBP, even when considering DSM-IV clinical status. CONCLUSIONS HRSZ and HRBP shared several aspects of their cognitive impairment. Our data suggest that the extremely high genetic and familial loading of these HRs may have contributed to a quantitatively increased magnitude of the cognitive impairments in both HR subgroups, especially in memory. These offspring at heightened risk present difficulties in processing information that warrant preventive research.

Family history of cognitive disabilities in first-degree relatives of autistic and mentally retarded children.

We compared with a family history method the rate of cognitive disabilities (CD) in 156 first-degree relatives of 49 autistic (AU) probands to that found in 55 first-degree relatives of 18 mentally retarded (MR) probands. Broadly defined CD were found in, respectively, 17 and 16% of the relatives of the AU and MR probands. However, the characteristics of the probands associated with a family history of CD are different in AU and MR: Female and low IQ AU probands have more first-degree relatives with CD. Our findings suggest that a positive family history of CD is not specific to autism when compared to mental retardation. The observation that female and low IQ probands have higher family history of CD may suggest heterogeneity within autistic children and provides leads for future family studies.

FAMILY CORRELATES OF TEMPERAMENT CONTINUITY AND CHANGE ACROSS MIDDLE CHILDHOOD

This paper reports on continuity and change of extreme traits of temperament from age seven to 12 in subgroups selected from a large random sample and on the association of continuity with certain aspects of family functioning. Results suggest a definite degree of stability of extreme temperament over time. Implications of the findings are discussed and directions for future research suggested.

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.