Neuroanatomical abnormalities in adolescents with attention-deficit/hyperactivity disorder.

Objective: Several neuroanatomic abnormalities have been reported in patients with attention-deficit/hyperactivity disorder (ADHD). However, findings are not always consistent, perhaps because of heterogeneous subject samples. Studying youths with documented familial ADHD provides an opportunity to examine a more homogeneous population.

Developmental trajectories of brain structure in adolescents with 22q11.2 deletion syndrome: a longitudinal study.

The 22q11.2 deletion syndrome (22q11.2DS) is associated with very high rates of schizophrenia-like psychosis and cognitive deficits.

Risk factors for the emergence of psychotic disorders in adolescents with 22q11.2 deletion syndrome.

Objective: The 22q11.2 deletion syndrome is the most common known genetic risk factor for the development of schizophrenia. The authors conducted a longitudinal evaluation of adolescents with 22q11.

The contribution of novel brain imaging techniques to understanding the neurobiology of mental retardation and developmental disabilities.

Studying the biological mechanisms underlying mental retardation and developmental disabilities (MR/DD) is a very complex task. This is due to the wide heterogeneity of etiologies and pathways that lead to MR/DD. Breakthroughs in genetics and molecular biology and the development of sophisticated brain imaging techniques during the last decades have facilitated the emergence of a field called Behavioral Neurogenetics.

COMT genotype predicts longitudinal cognitive decline and psychosis in 22q11.2 deletion syndrome.

Although schizophrenia is strongly hereditary, there are limited data regarding biological risk factors and pathophysiological processes. In this longitudinal study of adolescents with 22q11.2 deletion syndrome, we identified the catechol-O-methyltransferase low-activity allele (COMT(L)) as a risk factor for decline in prefrontal cortical volume and cognition, as well as for the consequent development of psychotic symptoms during adolescence.