Cognitive impairments associated with formal thought disorder in people with schizophrenia.

Formal thought disorder (FTD), or disorganized speech, is one of the central signs of schizophrenia. Despite extensive research, the cognitive processes associated with FTD are still unclear. However, the authors' review of FTD theories and research indicates that considerable progress has been made in identifying possible cognitive impairments associated with FTD. Specifically, FTD is strongly associated with impaired executive functioning and with impaired processing of semantic information. Their review indicates that previous research has not yet supported an association between FTD and either an increase in spreading activation or an impairment within the language production system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between formal thought disorder and executive functioning component processes.

In 2 studies, associations between formal thought disorder (FTD) and 2 components of executive functioning, processing of context and interference resolution, were investigated. One study, involving people with schizophrenia, examined associations between performance on processing of context (N-back) and interference resolution (interference in Steinberg probe recognition) tasks and FTD. The second study, involving nonpsychiatric participants, was an analogue study that examined the effects of simulated processing of context (performance of 1-back with distraction) and interference resolution (telling new stories about previously seen pictures) deficits on FTD in a speech production task. In both studies, processing of context deficits predicted FTD. Moreover, in both studies, the effect of processing of context deficits on FTD was especially pronounced when combined with interference resolution deficits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbal communication impairments and cognitive control components in people with schizophrenia.

Schizophrenia involves multiple communication impairments, including (a) disorganized speech, or formal thought disorder (FTD); and (b) decreased speech output, or poverty of speech. Both FTD and poverty of speech have been hypothesized to be associated with deficits in executive functioning or cognitive control. The current study examined whether FTD and poverty of speech were differentially associated with two distinct aspects of cognitive control, working memory and controlled retrieval. Compared with control participants (n = 30), people with schizophrenia (n = 47) exhibited poorer performance on both working memory and controlled retrieval tasks. However, only FTD (and not poverty of speech) was associated with poor working memory. In contrast, only poverty of speech (and not FTD) had a significant zero-order association with poor controlled retrieval. At the same time, working memory and controlled retrieval interacted to predict FTD, with the highest amount of FTD associated with both poor working memory and poor controlled retrieval. In contrast, psychometric control tasks were not associated with FTD or poverty of speech. This research suggests that FTD and poverty of speech are differentially associated with deficits in distinct aspects of cognitive control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Trauma and posttraumatic stress disorder in people with schizophrenia.

This study evaluated the hypothesis that trauma and posttraumatic stress disorder (PTSD) severity would be positively associated with schizophrenia symptoms. Forty-seven clients with schizophrenia were assessed for schizophrenia severity and for lifetime trauma history and PTSD symptoms in 2 independent symptom interviews; 35 (74%) participants reported at least 1 event in which there was threat of harm or life threat and subjective distress, and 6 (13%) had current PTSD. Trauma across the life span was associated with greater severity of PTSD. Within the total sample, PTSD symptoms were associated with greater emotional distress, but not with schizophrenia-specific symptoms. Distress among clients with schizophrenia and PTSD suggests the need for routine assessment of PTSD and development of PTSD interventions in this population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Referential Communication Disturbances in the Speech of Nonschizophrenic Siblings of Schizophrenia Patients.

Several different types of communication disturbances have been identified in the speech of schizophrenia patients. This study assessed 6 types of referential communication disturbances in the speech of 32 stable outpatients, 23 of their nonschizophrenic siblings, and 27 control subjects. The siblings made more frequent reference failures of all types than control subjects and did not differ from the patients on most types of disturbance. Only on the arguably most "schizophrenic" type of disturbance, the missing information reference, did patients show more deviance than siblings. On the vague reference, siblings showed more deviance than patients. These results, which are very similar to those previously reported on parents of patients, support the idea that referential disturbances reflect vulnerability to schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive Impairments and Disordered Speech in Schizophrenia: Thought Disorder, Disorganization, and Communication Failure Perspectives.

This article posits that basic cognitive impairments in schizophrenia are more highly related to speech disorder measured as communication failures than speech disorder measured as thought disorder or disorganization. The author tested 47 schizophrenia patients and 36 control participants for sustained attention, sequencing, and conceptual sequencing ability. Their speech was also rated for communication failures, thought disorder, and conceptual disorganization. Attention and sequencing impairments, examined hierarchically, explained a substantial 38% of the variance in the communication measure of speech disorder but little of the variance in formal thought disorder or conceptual disorganization. The author concludes that (a) impairments in attention and sequencing abilities contribute substantially to schizophrenic communication failures, and (b) it is important to consider lower level cognitive "3rd variables" when examining higher level cognitive associates of speech disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal discounting of rewards in patients with bipolar disorder and schizophrenia.

Patients with bipolar disorder (BD) and schizophrenia (SZ) often show decision-making deficits in everyday circumstances. A failure to appropriately weigh immediate versus future consequences of choices may contribute to these deficits. We used the delay discounting task in individuals with BD or SZ to investigate their temporal decision making. Twenty-two individuals with BD, 21 individuals with SZ, and 30 healthy individuals completed the delay discounting task along with neuropsychological measures of working memory and cognitive function. Both BD and SZ groups discounted delayed rewards more steeply than did the healthy group even after controlling for current substance use, age, gender, and employment. Hierarchical multiple regression analyses showed that discounting rate was associated with both diagnostic group and working memory or intelligence scores. In each group, working memory or intelligence scores negatively correlated with discounting rate. The results suggest that (a) both BD and SZ groups value smaller, immediate rewards more than larger, delayed rewards compared with the healthy group and (b) working memory or intelligence is related to temporal decision making in individuals with BD or SZ as well as in healthy individuals. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Neuropsychology, genetic liability, and psychotic symptoms in those at high risk of schizophrenia.

Neuropsychological assessments were compared among individuals at enhanced genetic risk of schizophrenia (n=157) and controls (n=34). The relationship between cognitive impairments and the presence of psychotic symptoms and measures of genetic risk was explored in the high-risk subjects. Neuropsychological differences were identified in many areas of function and were not accounted for by the presence of psychotic symptoms. Genetic liability was not associated with neuropsychological performance or with psychotic symptoms, but exploratory analysis showed some tests were associated with both liability measures. These results suggest that what is inherited is not the disorder itself but a state of vulnerability manifested by neuropsychological impairment, occurring in many more individuals than are predicted to develop the disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Affective reactivity of language symptoms, startle responding, and inhibition in schizophrenia.

The speech of some schizophrenia patients becomes markedly more disordered when negative affect is aroused. The authors tested associations between affective reactivity of speech and responsiveness and inhibition on an acoustic startle task in a sample of 27 outpatients. Patients whose language was reactive to negative affect showed significantly higher initial startle amplitudes than those whose language was not reactive. However, they also showed greater habituation to repeated startle stimuli over trials, even after differences in initial amplitudes were controlled statistically. These findings suggest that affective reactivity of speech is associated with higher initial startle responsiveness but also with greater habituation and, conversely, that patients who are relatively nonreactive to excitatory affective and sensory stimuli are also less reactive to inhibitory input. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Diagnostic differences in social anhedonia: A longitudinal study of schizophrenia and major depressive disorder.

This study examined the hypothesis that, in schizophrenia, elevated trait social anhedonia (SA) is a stable individual difference, whereas in depression, increased SA is a reflection of a current clinical state that will diminish with recovery. Differences in trait Negative Affect (NA) and Positive Affect (PA) were also examined. Individuals with schizophrenia (n?=?55) and depression (n?=?34) were evaluated at baseline during hospitalization and compared with nonpsychiatric control participants (n?=?41). Participants were assessed again at a 1-year follow-up. At baseline, compared with control participants, individuals with schizophrenia and depression were both characterized by elevated SA, greater NA, and lower PA. In schizophrenic individuals, elevated SA remained stable over the follow-up. However, in recovered depressed patients, SA declined over the follow-up period. Group differences remained in NA and PA over the 1-year follow-up. These results support the view that elevated SA is enduring in schizophrenia but that elevated SA is transiently related to clinical status in depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)