Neuropsychological profile of executive functions in autism spectrum disorder and schizophrenia spectrum disorders: a comparative group study in adults.

As assessed by numerous neuropsychological tasks, individuals with autism spectrum disorder (ASD) and schizophrenia spectrum disorders (SSDs) have similar impairments related to executive functions (EFs). The neuropsychological profile of these two conditions was examined using the three-component EFs' framework of Miyake and Friedman (Cogn Psychol 41(1):49-100, 2000). This approach assesses Inhibition (suppression of unwanted and irrelevant information/responses), Updating (use and control of contents of working memory), and Shifting (disengagement between activities or mental tasks) using nine different tasks. In line with previous research, we expected greater performance deficits in ASD in all three components compared to SSD, as well as faster responses for the SSD group. A self-paced task format allowed us to examine whether unlimited time given for a task would lead to better performance. The sample was constituted by the control group (N = 25), ASD group (N = 24), and SSD group (N = 12). Groups did not differ on Inhibition performance. In Updating, individuals with SSD performed poorer than the other groups. As for Shifting, both groups demonstrated poorer performance compared to controls, with the SSD group presenting the greatest difficulties. In terms of reaction time (RT), SSD participants' RT were the slowest on Inhibition and Shifting tasks. There was a positive correlation between performance and time spent on Inhibition and Shifting only for the SSD group, which demonstrates that their performance improves when there are no time constraints. Our work provides a better understanding of spared and impaired EFs, which could be useful for designing strategies aimed at improving specific EFs in each group.

Differences in daily life executive functioning between people with autism and people with schizophrenia.

This is a comparative analysis of everyday executive functioning between individuals with Autism Spectrum Disorder (ASD), Schizophrenia Spectrum Disorders (SSD) and controls using Dysexecutive Questionnaire-Spanish (DEX-Sp), to identify patterns of difficulties. Also we assessed the relationship between EF and adaptive behavior as measured by the Vineland Adaptive Behavioral Scale-II. Common areas of everyday executive functions were established as problematic in individuals with ASD and SSD related to Disinhibition and Apathy, while Disorganization and Impulsivity was gravely affected in ASD group only. The degree of Dysexecutive Syndrome was predictive of adaptive behavior in ASD group only. These suggest that DEX-Sp could be a useful tool in differentiating areas of strength and weaknesses in clinical groups such as ASD and SDD.

Executive functions in daily living skills: A study in adults with autism spectrum disorder.

Introduction: Adults with autism and adults with schizophrenia show difficulties in adaptive skills, especially those related to daily functioning. Some studies suggest that adaptive skills are associated with deficits in executive functions (EF), while others indicate that intelligence quotient (IQ) might also play a role. Literature suggests that autistic symptoms further affect adaptive skills. The interest of the current study, therefore, was to explore to what extent IQ, EFs as well as core autistic symptoms predict adaptive skills. Methods: To do this, 25 controls, 24 adults with autism, and 12 with schizophrenia were assessed on IQ (Wechsler Adult Intelligence Scale), and executive functioning. The EF was measured with neuropsychological tasks (inhibition, updating, and task switching) and with the Dysexecutive-Spanish Questionnaire (DEX-Sp) which assessed everyday life EF problems. Core ASD symptoms were measured using the Autism Diagnostic Observation Schedule, the Autism Spectrum Quotient-Short version (AQ-S), and the Repetitive Behavior Questionnaire - 3 (RBQ-3). Results: The results indicated EF difficulties in both, autism and schizophrenia. The IQ explained a high percentage of the variance found in adaptive skills, but only in the autism group. We can conclude, therefore, that high IQ is associated with low adaptive skills levels and EFs affect adaptive functioning in people with autism; however, this does not explain the difficulties in adaptive functioning in the schizophrenia group. Core features of autism assessed with self-report questionnaires (but not the ADOS-2) predicted low scores on the adaptive skills, only in the autism group. Discussion: Both EF measures predicted adaptive skills scores in autism, but not in schizophrenia. Our results suggest that different factors affect the adaptive functioning in each disorder. For instance, the EFs should be a central focus for improvement, especially for individuals with autism.