Formal Thought Disorder and the Autism Spectrum: Relationship with Symptoms, Executive Control, and Anxiety

Abstract

This study investigated whether children with autism spectrum disorders (ASDs) exhibit formal thought disorder (FTD), and whether this is related to ASD symptoms, executive control, and anxiety. Participants aged 8-17 with ASDs exhibited significantly more illogical thinking and loose associations than matched typically developing control subjects. In participants with ASDs, illogical thinking was related to aspects of cognitive functioning and to executive control. Loose associations were related to autism communication symptoms and to parent reports of stress and anxiety. When FTD is present in ASDs, it generally is not a co-morbid schizophrenia symptom, but is related to pragmatic language abnormalities found in ASDs. The clinical and neurobiological significance of this work is discussed. KeywordsAutism spectrum disorders; Schizophrenia; Thought disorder; Executive functions; Anxiety Autism and schizophrenia are heterogeneous disorders with presentations that vary across severity-graded spectra. There has been longstanding interest in understanding the Correspondence to: Marjorie Solomon. HHS Public AccessAuthor manuscript J Autism Dev Disord. Author manuscript; available in PMC 2017 July 20. Author Manuscript Author ManuscriptAuthor ManuscriptAuthor Manuscript relationship between these two disorders. Initially, it was believed that autism was the earliest manifestation of schizophrenia, which then presented fully in late adolescence or early adulthood (Bender 1947). Later, Kolvin (1971) and Rutter (1972) suggested the two disorders were functionally distinct, and empirical research demonstrated that individuals diagnosed with autism did not develop schizophrenia at a rate higher than the general population (Mouridsen et al. 1999;Sporn et al. 2004;Volkmar and Cohen 1991).More recently, it has been proposed that the presence of an autism spectrum disorder (ASD), including high functioning autism, Asperger's Disorder, and Pervasive Developmental Disorder Not Otherwise Specified (PDDNOS), may be a nonspecific marker of severe early abnormal neurodevelopment present in disorders including schizophrenia. Consistent with this view, multiple studies have documented premorbid childhood social difficulties and oddness in individuals later diagnosed with schizophrenia (Schiffman et al. 2004;Walker et al. 1993);and Sporn et al. (2004) found that ASD was present in 25% of a cohort of children diagnosed with early onset schizophrenia.Developing a better understanding of differences between the autism and schizophrenia is important both clinically and scientifically. For clinicians, early accurate diagnosis of both disorders is imperative given its association with improved language and social functioning in autism (Ozonoff et al. 2007) and the relationship between untreated illness duration and poor outcome in schizophrenia (Keshavan and Amirsadri 2007). Differential diagnosis of schizophrenia and ASDs can be challenging, however, because symptoms may be difficult to distinguish or even overlap (Sheitman et al...

What is the prevalence of autism spectrum disorder and ASD traits in psychosis? A systematic review

“…Both schizophrenia and ASD are considered to be chronic, multi-factorial disorders which include clinical presentations across a continuum of severity and disability. Issues pertaining to high heterogeneity within both constructs are therefore problematic for psychiatric classification systems which rely on the presence of specified clinical symptoms (Solomon et al, 2008). In addition to shared symptomatolgy and risk factors, genetic studies have highlighted direct and indirect links between ASD and schizophrenia (Hallerback et al, 2012).…”

Comparative genomics of autism and schizophrenia

“…Current diagnostic categorization places the most common childhood condition likely to involve premorbidity to schizophrenia, PDD-NOS, formally within the autism spectrum; this system thus implictly presumes either a general lack of premorbidity to schizophrenia sufficiently severe to result in autism spectrum diagnoses, or that autism and schizophrenia overlap in etiology and symptoms. The tendency for males to exhibit worse premorbidity to schizophrenia than females (87,88), and for earlier-onset schizophrenia to exhibit a higher male bias and a stronger tendency to be mediated by CNVs rather than other factors (89, 90) suggests a notable risk for false-positive diagnoses of autistic spectrum conditions (75)(76)(77)(91)(92)(93). Apparent direct evidence of such risk comes from tendencies to diagnose autism spectrum conditions in children with deletions at 15q11.2, 15q13.3, and 22q11.21, and duplications of 16p11.2, CNVs for which high risk of schizophrenia has been established from studies of adults (16,23,31,(94)(95)(96)(97).…”

The Psychiatric Presentation of Fragile X: Evolution of the Diagnosis and Treatment of the Psychiatric Comorbidities of Fragile X Syndrome

“…While formal thought disorders are generally considered rare in FXS, as in autism spectrum disorders [Solomon et al, 2008], antipsychotic medications are commonly used to treat affective lability, agitation, and aggression [McDougle et al, 2008]. Indeed, risperidone was the first treatment specifically approved by the FDA for treatment of autism symptoms (specifically, irritability).…”