Introduction: The aim of the present study was to determine whether individuals with Prader--Willi syndrome (PWS) have impaired global executive functioning and whether this deficit is linked with intellectual disability. Another objective focussed on the variability in performance of intellectual quotient (IQ) and executive functions (EF)…

Background: Twin studies using both clinical and population-based samples suggest that the frequent co-occurrence of attention deficit hyperactivity disorder (ADHD) and reading ability/disability (RD) is largely driven by shared genetic influences. While both disorders are associated with lower IQ, recent twin data suggest that the shared genetic…

The ranking of Wechsler subtests in terms of their "g" loadings is equivalent to ranking them in terms of the cognitive complexity of the tasks measured. Lower performing groups do not always fall behind higher performing groups the more complex the task. But that is the general rule, no matter whether the cause of the lower performance…

Background: Prader-Willi syndrome (PWS) is a rare genetic disorder characterised by developmental abnormalities leading to somatic and psychological symptoms. These include dysmorphic features, impaired growth and sexual maturation, hyperphagia, intellectual delay, learning disabilities and maladaptive behaviours. PWS is caused by a lack of…

In order to investigate unique and shared characteristics and to determine factors predictive of group classification, quantitative comparisons of behavioral and emotional problems were assessed using the Developmental Behavior Checklist (DBC-P) and the Vineland Adaptive Behavior Scales in autistic disorder, Williams syndrome (WS), and…

Background: Childhood onset schizophrenia (COS) is a rare disorder. Comparative data on the effect of differential age of onset on clinical profile in schizophrenia are very few. Method: Subjects with COS (n = 15), adolescence onset schizophrenia (AdOS, n = 20) and adulthood onset schizophrenia (AOS, n = 20) were compared on socio-demographic,…

Background: Prader-Willi syndrome (PWS) is associated with a characteristic behavioural phenotype whose main features are, alongside compulsive hyperphagia, deficits in social behaviour: social withdrawal, temper tantrums, perseverative speech and behaviour, mental rigidity, stereotyped behaviour, impulsiveness, etc. Similar symptoms may also be…