Features in families of boys with hyperkinetic and emotional disorders

Classical and Bayesian estimation in the logistic regression model applied to diagnosis of child attention deficit hyperactivity disorder

The limitations inherent to classical estimation of the logistic regression models are known. The Bayesian approach in statistical analysis is an alternative to be considered, given that it makes it possible to introduce prior information about the phenomenon under study. The aim of the present work is to analyze binary and multinomial logistic regression simple models estimated by means of a Bayesian approach in comparison to classical estimation. To that effect, Child Attention Deficit Hyperactivity Disorder (ADHD) clinical data were analyzed. The sample included 286 participants of 6-12 years (78% boys, 22% girls) with ADHD positive diagnosis in 86.7% of the cases. The results show a reduction of standard errors associated to the coefficients obtained from the Bayesian analysis, thus bringing a greater stability to the coefficients. Complex models where parameter estimation may be easily compromised could benefit from this advantage.

Family factors and children's disruptive behaviour: an investigation of links between demographic characteristics, negative life events and symptoms of ODD and ADHD

BACKGROUND

Oppositional defiant disorder behaviours (ODD) and attention deficit/hyperactivity disorder symptoms (ADHD) are common disruptive childhood problems and co-occur to a large extent. In this study, prime questions were the specificity of relations between demographic factors and negative life events, respectively, and ADHD and ODD symptoms, and the role of negative life events in the relations between demographic factors and ODD and ADHD symptoms.

METHODS

Concurrent relations between maternal education, family structure, ethnicity/immigrant background and symptoms of ADHD and ODD were investigated in a Swedish population sample of 1,200 10-year-old children (52% boys). Parents completed questionnaires containing information about demographic characteristics and negative life events and rated the child's ADHD and ODD symptoms using DSM-IV criteria.

RESULTS

Low maternal education, single/step-parenthood and non-European descent were associated with higher numbers of ODD and ADHD symptoms. Regression analyses identified ethnicity as specifically associated with ODD symptoms and single/step-parenthood as specific to ADHD symptoms, while there was no specificity with regard to negative life events. Experiences of multiple negative life events were more common in families in non-optimal circumstances. Negative life events had mainly additive effects on the level of ODD and ADHD symptoms above effects of the demographic stressors and especially conflicts between adults around the child were related to high symptom levels. The few gender effects pointed to boys as being more vulnerable than girls to non-optimal family factors expressed in relations to ODD and ADHD symptoms.

CONCLUSION

Even in an affluent and egalitarian society, children's life circumstances are related to their mental health. Further, there seems to be some specificity in the demographic risk factors associated with ODD and with ADHD symptoms, while negative life events act as general stressors.

Reconsidering the attention deficit paradigm

OBJECTIVE

To examine the inadequacies and criticisms of the current categorical paradigm of Attention Deficit Disorder both in children and adults.

CONCLUSIONS

An alternative, more dimensional paradigm linking executive functions is described and its advantage over categorical diagnostic paradigms is argued. Consideration of a more discriminating and dimensional behavioural model would help psychiatrists operating in this area.

Attention deficit/hyperactivity disorder (ADHD): complex phenotype, simple genotype?

Complex genetic traits refer to those phenotypes not fitting patterns of Mendelian segregation and/or assortment but exhibiting a preferential familial clustering that cannot be explained by cultural or environmental causes. Attention-deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder of childhood and probably the most controversial. ADHD has been considered a complex genetic trait based upon the absence of a clear-cut boundary between affected and unaffected status. Furthermore, its high comorbidity with other disorders strongly suggests complex epistatic or pleiotropic effects acting in common with the environmental influences. This implies that the same gene or genes is or are associated with different and concurrently occurring phenotypes. In this study, we will review clinical and epidemiological aspects related to the ADHD phenotype, which are considered either as categorical or continuous traits. We also will discuss genetic models underlying the complexity of this behavioral phenotype and the probable role of epistatic interactions between major genes contributing to the ADHD phenotype.