Thought Disorder in Schizophrenia and Bipolar Disorder Probands, Their Relatives, and Nonpsychiatric Controls

Abstract

Thought disorder (TD) has long been associated with schizophrenia (SZ) and is now widely recognized as a symptom of mania and other psychotic disorders as well. Previous studies have suggested that the TD found in the clinically unaffected relatives of SZ, schizoaffective and bipolar probands is qualitatively similar to that found in the probands themselves. Here, we examine which quantitative measures of TD optimize the distinction between patients with diagnoses of SZ and bipolar disorder with psychotic features (BP) from nonpsychiatric controls (NC) and from each other. In addition, we investigate whether these same TD measures also distinguish their respective clinically unaffected relatives (RelSZ, RelBP) from controls as well as from each other. We find that deviant verbalizations are significantly associated with SZ and are co-familial in clinically unaffected RelSZ, but are dissociated from, and are not co-familial for, BP disorder. In contrast, combinatory thinking was nonspecifically associated with psychosis, but did not aggregate in either group of relatives. These results provide further support for the usefulness of TD for identifying potential non-penetrant carriers of SZ-risk genes, in turn enhancing the power of genetic analyses. These findings also suggest that further refinement of the TD phenotype may be needed in order to be suitable for use in genetic studies of bipolar disorder.

Cross Talk: The Microbiota and Neurodevelopmental Disorders

“…schizophrenia is classically characterized by positive (delusions, hallucinations), negative (affective flattening, alogia, and avolition), and cognitive symptoms (Aleman et al, 1999 ; Kahn and Keefe, 2013 ; Schaefer et al, 2013 ). Social interaction and communication deficiencies, including disorganized speech, can be prominent, even early in the course of this disorder (Sullivan et al, 2003 ; Roche et al, 2016 ; Morgan et al, 2017 ).…”

Linguistic determinants of formal thought disorder in first episode psychosis

“…FTD captures a number of non‐specific thought/language anomalies (Andreasen, 1986) that are evident across a wide range of mental health and cognitive disorders including psychosis, bipolar disorder (Morgan et al, 2017), depression and Autism Spectrum Disorder (Eussen et al, 2015), as well as among healthy controls, albeit in subtler forms (Kircher, Bröhl, Meier, & Engelen, 2018; Kuperberg, 2010). FTD has been assessed historically as a categorical variable (Hart & Lewine, 2017), which fails to adequately describe the breadth of dysfunction under the umbrella of FTD.…”

Is formal thought disorder in schizophrenia related to structural and functional aberrations in the language network? A systematic review of neuroimaging findings

“…As FTD affects the thought process as well as thought expression, it is defined as a severe language and speech disturbance (Hart and Lewine, 2017). It occurs in the general population (Rossler et al, 2013), in relatives of patients with schizophrenia (Morgan et al, 2017), in people at high risk of developing psychosis (Demjaha et al, 2012;Katsura et al, 2014), as well as in patients with non-affective psychoses, affective psychoses, and nonpsychotic disorders . Prevalence rates, which are dependent on the assessment method used, are highest in schizophrenia (50-80%), followed by schizoaffective disorders (60%), depression (53%), and healthy controls (6%).…”