Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by restricted, repetitive patterns of behavior and interests (RRBIs). With the latest update to the Diagnostic and Statistical Manual of Mental Disorders, a severity level rating is assigned to the two core features of ASD (American Psychiatric Association in Diagnostic…

A growing body of research suggests that symptoms of autism spectrum disorder (ASD) may present differently in males and females. This study examined gender differences in ASD symptoms and developmental functioning, using the "Baby and Infant Screen for Children with aUtism Traits, Part 1" (BISCUIT-Part 1) and the "Battelle…

The Autism Spectrum Disorder Observation for Children (ASD-OC) is a 45-item observation scale used to assess autistic symptomatology. The reliability of this measure has been established in previous research; therefore, the purpose of this study is to evaluate its validity among a sample of children (1-15 years). The large correlation between the…

A multiple mediation model was proposed to integrate core concepts of challenging behaviors with autistic traits to increase understanding of their relationship to quality of life (QoL). It was hypothesized that QoL is a possible mediator between the severity of challenging behaviors and autistic traits in adults with intellectual disability.…

Challenging behaviors are deemed extremely common within the autism spectrum disorders (ASD) population. Numerous factors and their effects upon the presence and severity of challenging behaviors within this population have been investigated. However, there has been limited research to investigate the effects of cultural differences on challenging…

Little research has been conducted to date on the relationship between psychotropic medication use and autism spectrum disorders (ASDs). Participants in the current study were placed into one of four groups: ASD on psychotropic medications (N = 33), ASD off psychotropic medications (N = 45), atypically developing on psychotropic medications (N =…

Little research has been conducted on whether deficits in developmental functioning affect the range of core symptoms for autism spectrum disorders (ASD). This study represents a first attempt to determine whether developmental level has an effect on the expression of ASD symptoms in infants and toddlers. Eight hundred and fifty-three infants were…

Autism Spectrum Disorders (ASDs) are characterized by pervasive impairments in repetitive behaviors or interests, communication, and socialization. As the onset of these features occurs at a very young age, early detection is of the utmost importance. In an attempt to better clarify the behavioral presentation of communication and socialization…

A preponderance of males with autism spectrum disorders (ASD) has been evident since the initial writings on the topic. This male predominance has consistently emerged in all ASD research to date in epidemiological as well as clinical populations. Despite this long recognized gender disparity in ASD, surprisingly there is a paucity of research…

Little is known about the symptoms of anxiety in very young children with autism spectrum disorders, particularly comparisons between Autistic Disorder (AD) and Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS). In the current study, toddlers (i.e., 17-37 months of age) with diagnoses of either AD (N = 159) or PDD-NOS (N = 154)…

The prevalence of toileting problems was assessed in 153 adults with intellectual disability (ID) using the "Profile of Toileting Issues" ("POTI") and comparisons were made based on various demographic variables. The most frequently endorsed problems were "has toileting accidents during the day," "has toileting…

The effect of developmental quotient on symptoms of inattention and impulsivity was examined among 198 toddlers with Autism Spectrum Disorders. There were two levels of developmental quotient: (1) low (less than or equal to 70; n = 80), and (2) typical (greater than 70; n = 118). Symptoms of inattention and impulsivity were assessed using 14 items…

Intellectual disability (ID) and autism spectrum disorders (ASDs) covary at very high rates. Similarly, greater severity of one of these two disorders appears to have effects on the other disorder on a host of factors. A good deal of research has appeared on the topic with respect to nosology, prevalence, adaptive functioning, challenging…

Social skills are defining aspects of intellectual disability (ID). Additionally, their presence or absence can be a major impediment to independent living, and they correlate with other problems in the ID population, such as comorbid psychopathology. To date, little has been done to develop scales to measure these problems, particularly for…

Autism spectrum disorders (ASD) and intellectual disabilities (ID) are high prevalence developmental disabilities that co-occur at high rates. Furthermore, Axis I psychopathology is known to occur more frequently in individuals with ID than the general population. The problems are lifelong and can be major impediments to independent living.…