Puerta Ic

Potential cognitive endophenotypes in multigenerational families: segregating ADHD from a genetic isolate

Endophenotypes are neurobiological markers cosegregating and associated with illness. These biomarkers represent a promising strategy to dissect ADHD biological causes. This study was aimed at contrasting the genetics of neuropsychological tasks for intelligence, attention, memory, visual-motor skills, and executive function in children from multigenerational and extended pedigrees that cluster ADHD in a genetic isolate. In a sample of 288 children and adolescents, 194 (67.4%) ADHD affected and 94 (32.6%) unaffected, a battery of neuropsychological tests was utilized to assess the association between genetic transmission and the ADHD phenotype. We found significant differences between affected and unaffected children in the WISC block design, PIQ and FSIQ, continuous vigilance, and visual-motor skills, and these variables exhibited a significant heritability. Given the association between these neuropsychological variables and ADHD, and also the high genetic component underlying their transmission in the studied pedigrees, we suggest that these variables be considered as potential cognitive endophenotypes suitable as quantitative trait loci (QTLs) in future studies of linkage and association.

Neurobehavioral Characteristics of Adolescents with Behavioral Dysregulation Disorder

Background There is growing recognition that violence and other forms of conduct problems increase during adolescence. The exact relationship between biological, psychological, and social variables has not been defined yet. Objectives To analyze whether Intelligence Quotients (IQS), neurological history, child behavioral problems, executive functions, and soft neurological signs (SNS) can differentiate between undisciplined and unreliable adolescents (Behavioral Dysregulation Disorder subjects, BDD) and normal controls. Method Twenty-five 13 to 16-year-olds, adolescents with BDD and 25 matched controls were used in this study. WISC-R, executive function assessment, neurological history, child behavioral problems, and SNS scores were analyzed using a Multivariate Analysis of Variance (MANOVA). A Multiple Regression Stepwise with Criteria Probability of F Analysis was used for predicting criteria variable variance-Results WISC-R Verbal 1Q (VIQ), Information, Similarities, and Vocabulary subtests presented statistically significant differences between BDD and controls (p <. 001). No Performance IQ (P1Q) variables established significant differences between both groups. Executive function scores did not detect significant differences between groups either. Prenatal, neonatal, and neurological history scores were similar between both groups. Two child behavioral problem variables were significantly different, with higher scores in BDD group: use of weapons and drug-use (p <. 05). A Multiple Regression Stepwise (Criteria Probability of F <. 05) model, entering the predictive variables in each domain

Screening for Conduct Disorder in an Adolescent Male Sample from Colombia

This study assessed the validity, reliability, and utility of a screening measure for detecting the signs or symptoms of Conduct Disorder in male adolescents from schools in Medellín, Colombia. A first study examined the differences between 70 male offender adolescents (aged 12-16 years) attending alternative education institutions, and 68 (sex, age, and socioeconomic status (SES)-matched) adolescent controls attending regular schools. A CD checklist (CD-CL) was constructed to be used by mothers (CD-CL-M) and for self-report by adolescents (CD-CL-SR). The validity of the screener for CD diagnosis was supported by significant differences between groups (ANOVA, p < .001). The CD-CL-SR had better sensitivity/specificity with a diagnostic cut-off point of 5 (sensitivity = 95.3% and specificity = 90.5%) than the CD-CL-M. A second study used the CD-CLSR with a random sample of 190 male adolescents (aged 12 to 16 years) from schools of low, middle and high SES. Reliability as assessed by Cronbach’s alpha was 0.86. An epidemiological cut point of 5 classified 35.5% of the adolescents assessed as probable CD cases. A psychometric cut point at T score > 59 (85th percentile) estimated 16.8% of the sample as probable CD cases. A psychometric cut point at T score > 64 (90th percentile) revealed that 10.5% of the sample would be severe CD cases. Some significant differences (p < 0.001) in proportions of CD adolescents were found between age and SES groups. It was concluded that such a high frequency of conduct problems in adolescence argues for the need for preventive programs in Colombian schools.