Comparison of schizophrenic patients with formal thought disorder and neurologically impaired patients with aphasia

This study compares the speech and language of 14 schizophrenic patients having a formal thought disorder with 13 neurologically impaired patients with aphasia. Transcribed interviews with these patients were blindly assessed by five specialists for classification as schizophrenic or aphasic. Three of the five specialists performed better than chance but only one achieved high discriminating ability. Interrater reliability was poor. Five of 14 language abnormalities assessed differentiated the diagnostic groups. These findings suggest that schizophrenic patients share many language abnormalities with aphasic patients but do not exhibit a classic aphasic syndrome.     

Information processing deficits of schizophrenic children with formal thought disorder

The relations among formal thought disorder, the partial report span of apprehension task, the distractibility factor on the Wechsler Intelligence Scale for Children-Revised (WISC-R), and IQ scores were examined in 31 schizophrenic children, aged 7.4 to 12.5 years. The partial report span of apprehension scores of the schizophrenic children correlated significantly with their illogical thinking scores. Their scores on loose associations were significantly associated with the WISC-R distractibility factor score. The attention/information processing deficits that might underlie the clinical manifestations of illogical thinking and loose associations in childhood onset schizophrenia are discussed.     

Sustained attention in patients with obsessive-compulsive disorder: a controlled study

Studies on attentional processes in obsessive-compulsive disorder (OCD) have been inconsistent. The present study focused on the question of sustained attention in OCD, using the 'Degraded Stimulus Continuous Performance Test' (DS-CPT) sensitivity index over time. This study included 20 OCD patients and 25 control subjects, comparable in sex, age and educational level. All subjects had a neuropsychiatric structured diagnostic interview, as well as a psychometric battery. The DS-CPT evaluated sustained attention. The sensitivity decrement during DS-CPT was significant in both controls and OCD subjects. Contrary to our expectations, OCD patients did not show a greater decrease in sensitivity over time, compared to controls: thus, OCD patients presented a no more important attention decrease than controls. Controls and OCD subjects became more conservative in their response criteria throughout the DS-CPT test. Comparing OCD with and without pharmacological treatment did not reveal any difference in CPT outcome. Moreover, we observed, in OCD, a positive significant correlation between the Y-BOCS compulsion score and the CPT sensitivity index. A significant negative correlation of the Y-BOCS compulsive score with the CPT false alarm score was also found. In conclusion, OCD patients did not present any disturbance in sustained attention during a task requiring an increased processing load.     

有无注意障碍的精神分裂症对照研究

目的：探讨有无注意障碍的精神分裂症患者间的临床差异。方法：在住院的精神分裂症患者中，以有注意障碍者为研究组，无注意障碍者为对照组，对两组病人的年龄、病程、用药剂量、药物副反应、疾病分型、疗效、症状量表评分、智能水平及神经系统软体征（NSS）进行比较。结果：两组病人除用CCMD-3诊断标准划分的亚型、用药剂量、药物副反应无显著性统计学差异外，其他各项指标均有显著性统计学差异。结论：研究组缺陷型病人多、年龄大、病程长、病情重、疗效及社会功能差、具有更为明显的NSS。     

Neurocognitive and social cognitive correlates of formal thought disorder in schizophrenia patients

The neurocognitive and social cognitive correlates of two types of formal thought disorder (i.e., bizarre-idiosyncratic and concrete thinking) were examined in 47 stable outpatients with schizophrenia. Both types of thinking disturbance were related to impairments in verbal learning, intrusions in verbal memory, immediate auditory memory, sustained attention, and social schema knowledge. Distractibility during an immediate memory task was associated with more frequent bizarre verbalizations but not concreteness. Impaired verbal learning rate and intrusions in verbal memory independently contributed to the prediction of bizarre responses, whereas intrusions in verbal memory and impaired immediate memory independently contributed to concrete thinking. This pattern of findings is consistent with the view that neurocognitive and, possibly, social cognitive deficits underlie these two aspects of formal thinking disturbance in schizophrenia.     

Effects of attention on dichotic listening: an 15O-PET study

The present study investigated the effect of attention on brain activation in a dichotic listening situation. Dichotic listening is a technique to study laterality effects in the auditory sensory modality. Two different stimuli were presented simultaneously, one in each ear. Twelve subjects listened to lists of consonant-vowel syllables, or short musical instrument passages, with the task of detecting a "target" syllable or musical instrument by pressing a button. The target stimulus appeared an equal number of times in the left and right ear. The subjects were instructed to either concentrate on the stimuli presented in both ears, or only on the left or right ear stimulus. Brain activation was measured with 15O-PET, and significant changes in regional normalized counts (rNC) were evaluated using statistical parametric mapping (SPM96) software. Concentrating on either the right or left ear stimulus significantly decreased activity bilaterally in the temporal lobes compared to concentrating on both ear stimuli, at the expense of an increased activation in the right posterior and inferior superior parietal lobe. The CV-syllables activated areas corresponding to the classic language areas of Broca and Wernicke. The musical instrument stimuli mainly activated areas in visual association cortex, cerebellum, and the hippocampus. An interpretation of the findings is that attention has a facilitating effect for auditory processing, causing reduced activation in the primary auditory cortex when attention is explicitly recruited. The observed activations in the parietal lobe during the focused attention conditions could be part of a modality non-specific "attentional network".     

Empirical assessment of the factorial structure of clinical symptoms in schizophrenic patients: formal thought disorder.

Male schizophrenic patients (n = 142) were examined with a clinical assessment of their language dysfunctions with the Scale for the Assessment of Thought, Language, and Communication (TLC). Confirmatory factor analyses were conducted to test the relative fit of several differential theoretical models of the factorial structure of thought disorders. The models examined were positive-negative thought disorder, a three-factor model based on the results of an earlier exploratory factor analysis, and a simpler verbal productivity-disconnection model that can be extracted from other exploratory analyses and empirical studies. The positive-negative thought disorder model failed to fit the data, while the three-factor model fit the data, but no better than the simpler verbal productivity-disconnection model.     

Differential activation of temporal cortex during sentence completion in schizophrenic patients with and without formal thought disorder

The neural correlates of processing linguistic context in schizophrenic patients with formal thought disorder (FTD) were examined. Six right-handed male patients with prominent 'positive' FTD were compared with six schizophrenic patients without FTD and seven volunteers, matched for cognitive and demographic variables. Functional magnetic resonance imaging (IMRI) was used to measure cerebral activation while subjects read and completed sentence stems out loud. During a GENERATION condition, subjects were required to generate a word which completed the sentence stem appropriately. During a DECISION condition, subjects selected and articulated one of two presented terminal words. A READING condition served as baseline. The three conditions were compared with each other. Regions activated were identified in each group, and between-group differences were detected using an ANCOVA. When GENERATION was compared with READING, FTD patients showed less activation in the right superior temporal gyrus than patients without FTD or controls, but greater activation in the left inferior frontal, inferior temporal and fusiform gyri. FTD patients also showed an attenuated right temporal response when GENERATION was compared with DECISION. This differential engagement of the right temporal cortex was independent of differences in the speed or accuracy of responses, whereas the left fronto-temporal differences in activation were not evident after covarying for task errors. The attenuated engagement of right temporal cortex, which is implicated in language comprehension at the discourse level, is consistent with neuropsychological evidence linking thought disorder with deficits in processing linguistic context.     

Neural correlates of formal thought disorder in schizophrenia: preliminary findings from a functional magnetic resonance imaging study

BACKGROUND: Formal thought disorder (FTD) is a core symptom of schizophrenia, but its pathophysiology is little understood. We examined the neural correlates of FTD using functional magnetic resonance imaging. METHODS: Blood oxygenation level-dependent contrast was measured using functional magnetic resonance imaging while 6 patients with schizophrenia and 6 control subjects spoke about 7 Rorschach inkblots for 3 minutes each. In patients, varying degrees of thought-disordered speech were elicited during each "run." In a within-subject design, the severity of positive FTD was correlated with the level of blood oxygenation level-dependent contrast in the 2 runs that showed the highest variance of FTD in each patient. RESULTS: The severity of positive FTD in patients was negatively correlated (P<.001) with signal changes in the left superior and middle temporal gyri. Positive correlations were evident in the cerebellar vermis, the right caudate body, and the precentral gyrus. CONCLUSIONS: The severity of positive FTD was inversely correlated with the level of activity in the Wernicke area, a region implicated in the production of coherent speech. Reduced activity in this area might contribute to the articulation of incoherent speech. Because of the small sample size, these findings should be considered preliminary.     

A controlled study of formal thought disorder in children with autism and multiple complex developmental disorders

Along with well-defined categories in classification systems (e.g., autistic disorders and attention-deficit/hyperactivity disorder (ADHD)), practitioners are confronted with many children showing mixed forms of developmental psychopathology. These clusters of symptoms are on the borderlines of more defined categories. The late Donald Cohen proposed heuristic criteria to study a group defined by impaired social sensitivity, impaired regulation of affect, and thinking disorders under the name multiple complex developmental disorders (MCDD). Although these children meet criteria for pervasive developmental disorder--not otherwise specified (PDD-NOS), they have additional important clinical features, such as thought disorder. After highlighting similarities and differences between MCDD and comparable groups (e.g., multidimensionally impaired children), this paper presents the findings of a study comparing formal thought disorder scores in children with MCDD to children with autism spectrum diagnoses, such as autistic disorder (AD), and to children with nonspectrum diagnoses, such as ADHD and anxiety disorders. METHODS: Videotaped speech samples of four groups of high-functioning, latency-aged children with MCDD, AD, ADHD, and anxiety disorders were compared to a control group of normal children using the Kiddie Formal Thought Disorder Rating Scale (K-FTDS). RESULTS: High formal thought disorder scores were found both in the AD and MCDD groups, low rates in the ADHD groups, and no thought disorder in the anxiety disorder and normal control groups. The severity of formal thought disorder was related to verbal IQ scores within the AD and MCDD groups. CONCLUSION: High formal thought scores in children with complex developmental disorders, such as AD and MCDD, appear to reflect impaired communication skills rather than early signs of psychosis.     

Neural correlates of formal thought disorder: An activation likelihood estimation meta‐analysis

Formal thought disorder (FTD) refers to a psychopathological dimension characterized by disorganized and incoherent speech. Whether symptoms of FTD arise from aberrant processing in language‐related regions or more general cognitive networks, however, remains debated. Here, we addressed this question by a quantitative meta‐analysis of published functional neuroimaging studies on FTD. The revised Activation Likelihood Estimation (ALE) algorithm was used to test for convergent aberrant activation changes in 18 studies (30 experiments) investigating FTD, of which 17 studies comprised schizophrenia patients and one study healthy subjects administered to S‐ketamine. Additionally, we analyzed task‐dependent and task‐independent (resting‐state) functional connectivity (FC) of brain regions showing convergence in activation changes. Subsequent functional characterization was performed for the initial clusters and the delineated connectivity networks by reference to the BrainMap database. Consistent activation changes were found in the left superior temporal gyrus (STG) and two regions within the left posterior middle temporal gyrus (p‐MTG), ventrally (vp‐MTG) and dorsally (dp‐MTG). Functional characterization revealed a prominent functional association of ensuing clusters from our ALE meta‐analysis with language and speech processing, as well as auditory perception in STG and with social cognition in dp‐MTG. FC analysis identified task‐dependent and task‐independent networks for all three seed regions, which were mainly related to language and speech processing, but showed additional involvement in higher order cognitive functions. Our findings suggest that FTD is mainly characterized by abnormal activation in brain regions of the left hemisphere that are associated with language and speech processing, but also extend to higher order cognitive functions. Hum Brain Mapp 38:4946–4965, 2017. © 2017 Wiley Periodicals, Inc.     

Measuring thought disorder with clinical rating scales in schizophrenic and nonschizophrenic patients

The distinction between disorders of thought structure and disorders of thought content in a diagnostically heterogeneous psychiatric population was empirically tested using factor analysis applied to the item scores on two common clinical rating scales, the Brief Psychiatric Rating Scale and Andreasen's Thought, Language, and Communication Scale. The factor structure supported the separation of disordered thinking into disorders of thought content and disorders of thought structure or communication. Additionally, our results indicate that both aspects of disordered thinking are present in schizophrenic and manic patients; neither is specifically characteristic of schizophrenia. Indeed, disordered thought structure appears to be more common or worse in the manic patient than in the schizophrenic patient.     

The neural correlates of ego-disturbances (passivity phenomena) and formal thought disorder in schizophrenia

Ego-disturbances (passivity phenomena) and formal thought disorder are two hallmark symptoms of schizophrenia. Formal thought disorder has been highlighted already very early by Eugen Bleuler in his concept of basic symptoms (Grundsymptome). In contrast ego-disturbances (Ich-Störungen) or passivity phenomena have been declared as core symptoms of schizophrenia by Kurt Schneider in his concept of first-rank symptoms (Erstrangsymptome) that influenced the whole concept of schizophrenia until today (ICD10; DSM IV). We present new neuroimaging and cognitive neuropsychological results that help to explain what brain and cognitive functions may be involved in the emergence of these symptoms. Questions on cognitive and neural correlates of notions such as self-awareness, self-consciousness, introspective perspective or subjective experiences have re-emerged as topics of great interest in the scientific community. Employing new neuroscientific methods such as functional brain imaging, advances into thus far unexplored territory of mind–brain relationships have been made. These findings give new impulses for the search on the neural basis of psychopathological symptoms. We will review neuroscientific data and models on the pathogenesis of two of the core symptoms of schizophrenia, i.e. passivity phenomena and formal thought disorder.

     

Subclinical thought disorder in first-degree relatives of schizophrenic patients. Results from a matched-pairs study with the Thought Disorder Index

To assess the frequency and quality of formal thought disorder in schizophrenic patients and their first-degree relatives, a consecutive series of 36 unmedicated patients, 20 siblings of these patients and 37 normal control subjects were examined with Holzman's Thought Disorder Index (TDI). As a proof of the internal validity of this tool, the patients demonstrated significantly more thought disorder than the controls as measured by the TDI total score and various subscores, which proved the internal validity of this tool in a German-speaking sample. In addition, in a pairwise comparison with controls who were individually matched by age and sex the patients’ siblings had a significantly higher total TDI score and nonsignificant elevations on several subscores (combinatory and flippant). As to the level of severity of the thought disorder, the siblings mostly took an intermediate position between patients and controls. In conjunction with previous reports from other authors, our findings lend further support to the notion of subclinical thought disorder as an indicator of familial vulnerability to schizophrenia.