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.     

Neurocognitive functioning in patients with first-episode schizophrenia

To assess the course of neuropsychological (NP) impairment in schizophrenia, 71 patients with first episode (FE) schizophrenia and 71 healthy controls were given a comprehensive battery of NP tests at index assessment, after a 2-year and after a 5-year follow-up period. By means of the z-score standardization, summary scores for verbal intelligence (VBI), spatial organisation (SPT), verbal fluency (VBF), Verbal learning (VBL), semantic memory (SEM), visual memory (VIM), delay/retention rate (DEL), short-term memory (STM), visuomotor processing and attention (VSM) and abstraction/flexibility (ABS) were constructed. FE schizophrenia patients showed a worse performance compared to controls in all areas investigated, most pronounced in VSM, SEM and VBL. In the majority of cognitive domains, an improvement was found over the 5-year follow-up period without differences between the two groups. However, in VBF patients slightly deteriorated whilst controls improved and in memory functions patients improved less compared to controls. When controlling for relevant confounders, neither conventional nor atypical neuroleptics showed a deleterious influence on NP performance, except on VBF. Our data suggest that NP impairment is already present at the onset of the illness and remains stable over the early course of schizophrenia.     

Obsessive-compulsive disorder in patients with first-episode schizophrenia

OBJECTIVE: The aim of the present study was to determine the rate of obsessive-compulsive disorder (OCD) in patients with first-episode schizophrenia. METHOD: Fifty patients consecutively hospitalized with first-episode psychosis who met DSM-IV criteria for schizophrenia spectrum disorders were assessed for OCD. The instruments used were the Structured Clinical Interview for DSM-IV, Schedule for the Assessment of Positive Symptoms (SAPS), Schedule for the Assessment of Negative Symptoms (SANS), and Yale-Brown Obsessive Compulsive Scale. RESULTS: Seven (14%) of the 50 schizophrenic patients met DSM-IV criteria for OCD and scored significantly lower than schizophrenic patients without OCD on the formal thought disorder subscale of the SAPS and the flattened affect subscale of the SANS. CONCLUSIONS: OCD is relatively frequent in patients with first-episode schizophrenia and may have a "protective" effect on some schizophrenic symptoms, at least in the early stages of the disease.     

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.

     

Two new scales of formal thought disorder in schizophrenia

Information provided by patients and respective carers may help to understand formal thought disorder (FTD) in schizophrenia. Two scales, one for patients (FTD-patient) and one for carers (FTD-carer), were constructed to assess pragmatics, cognitive, paralinguistic, and non-verbal aspects of communication. In the first scale the patients themselves assess their verbal communication; in the second scale the carer assesses the speech of the respective patient. Both scales exhibited internal reliability and evidence of good test-retest reliability. Higher total scores on both scales (FTD-patient and FTD-carer) were significantly associated with positive FTD, but not with negative FTD. Principal component analysis of the scales yielded a multidimensional structure. It is suggested that FTD in schizophrenia may be associated with a range of deficits (e.g. pragmatics, lexical activation, working memory, sustained attention). These scales, in conjunction with the clinician's assessment, can provide a more comprehensive picture of FTD in schizophrenia, revealing its dimensions and making it possible to establish associations between symptoms of FTD and neuropsychological, neurophysiologic, and neuroimaging data. In addition, they provide service users' and carers' perspectives for the assessment of communication in schizophrenia.     

Higher-order semantic processing in formal thought disorder in schizophrenia

Higher-order semantic impairments and lack of sensitivity to linguistic context have both been implicated in formal thought disorder (FTD) in schizophrenia. Most investigations have focused on comprehension. We investigated the processing of higher-order semantic relations and the role of emotional arousal in FTD patients? linguistic comprehension and production. We compared FTD schizophrenia patients (n=14) with non-FTD schizophrenia patients (n=18) and healthy controls (n=15) on sense-judgment and repetition tasks, in emotionally negative and neutral conditions. We predicted that the FTD group would display poor sensitivity compared to the other two groups in comprehension and production, and that this would be exacerbated by sentence complexity and negative emotional arousal. The emotional manipulation was not robustly successful, and did not affect task performance in the patient groups. FTD patients made significantly more errors on sense-judgments and repetition than the other two groups. Complexity affected all groups to a similar extent in sense-judgments, but affected FTD patients disproportionately in the repetition task. These results support the view that a lack of sensitivity to context underlies FTD in comprehension and production stages of processing. Patients fail to utilise linguistic context to integrate lexical forms into a global whole and guide their access to lexical targets.     

Relation of formal thought disorder to symptomatic remission and social functioning in schizophrenia

ObjectiveThe aim of this cross-sectional study is to examine the relation of formal thought disorder (FTD) with symptomatic remission (SR) and social functioning in patients with schizophrenia.MethodThe study was carried out with a sample consisting of 117 patients diagnosed with schizophrenia according to DSM-IV. The patients were assessed with the Positive and Negative Syndrome Scale (PANSS), the Thought and Language Index (TLI), and the Personal and Social Performance Scale (PSP). We used logistic regression in order to determine the relation between FTD and SR and linear regression to identify the strength of association between FTD and social functioning.ResultsLogistic regression analysis revealed that poverty of speech (odds ratio: 1.47, p < 0.01) and peculiar logic (odds ratio: 1.66, p = 0.01) differentiated the remitted patients from the non-remitted ones. Linear regression analysis showed that the PSP total score was associated with poverty of speech and peculiar logic items of the TLI (B = −0.23, p < 0.01, B = −0.24, p = 0.01, respectively).ConclusionOur findings suggest that poverty of speech and peculiar logic are the specific domains of FTD which are related to both SR status and social functioning in patients with schizophrenia.     

强迫症患者与精神分裂症患者的神经认知功能特征比较

目的 比较强迫症患者与精神分裂症患者神经认知损害的特点和严重程度. 方法 选择中山大学附属第三医院精神心理科自2011年8月至2012年2月住院的30例强迫症患者(强迫症组)、30例精神分裂症患者(精分症组)及同期30名体检健康者(对照组)为研究对象,采用连线测验、Stroop色字词测验、韦氏记忆测验、改良版威斯康辛卡片分类测验对其进行神经认知功能评定,并应用统计学方法比较. 结果 (1)在连线测验中,强迫症组的连线B测验用时(s)和连线A/B测验用时差要明显差于对照组,差异有统计学意义(P＜0.05);除连线B测验错误次数外,强迫症组其余指标均明显优于精分症组,差异有统计学意义(P＜0.05);精分症组各项指标均明显差于对照组,差异有统计学意义(P＜0.05).(2)在Stroop色字词测验中,强迫症组的色词测验错误率和色词测验用时明显差于对照组,差异有统计学意义(P＜0.05);强迫症组的字测验错误数和字测验用时明显优于精分症组,差异有统计学意义(P＜0.05);精分症组各项指标均明显差于对照组,差异有统计学意义(P＜0.05).(3)在韦氏记忆测验中,强迫症组的图片回忆、再认、联想学习、短时记忆和记忆商数明显差于对照组,差异有统计学意义(P＜0.05);除长时记忆、再认、联想学习和触觉记忆外,强迫症组的其余指标均明显优于精分症组,差异有统计学意义(P＜0.05);精分症组各项指标均明显差于对照组,差异有统计学意义(P＜0.05).(4)在改良版威斯康辛卡片分类测验中,强迫症组(除随机错误数外)和精分症组各项指标与对照组相比均明显差,差异有统计学意义(P＜0.05);强迫症组各项指标均明显优于精分症组,差异有统计学意义(P＜0.05). 结论 强迫症患者的神经认知缺陷特征主要表现在注意狭窄和转换困难,短时记忆和视空间记忆障碍;精神分裂症则表现为全面的神经认知功能损害;强迫症患者总体神经认知功能水平比精神分裂症患者高.     

Cognitive substrates in semantic memory of formal thought disorder in schizophrenia

Formal thought disorder (FTD) has been associated with abnormalities in the semantic memory system. However, it is still unclear whether these abnormalities are related to the organization of the semantic system, or to the automatic spread of activation-inhibition in semantic networks. In this paper these alternative proposals are examined. Schizophrenic patients and healthy matched controls were given two semantic memory tasks. In the first task, participants were required to judge the similarity between pairs of natural concepts. These ratings are assumed to reflect the underlying knowledge organization. In the second task, participants were required to name pictures that were preceded by related or unrelated word primes. Interference is typically observed when pictures are preceded by semantically related primes, and it is explained as due to inhibitory processes from the word prime to the related picture target. The results showed that the semantic structures derived from the similarity ratings were similar for patients with and without FTD and for control participants. However, results from the picture-naming task indicated that both non-FTD and control participants showed the normal interference/inhibition effects from the related prime words, whereas the patients with FTD showed similar performance for pictures preceded by related words than for pictures preceded by unrelated words. These findings support the hypothesis that abnormalities in inhibitory processes in semantic memory underlie FTD.     

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.     

N400 anomalies in schizophrenia are correlated with the severity of formal thought disorder

We explored the link between N400 anomalies and clinical profile in schizophrenia patients. N400 was recorded in 50 schizophrenia patients and 40 healthy controls during a lexical decision task with semantic priming. Comparison between controls and schizophrenia patients showed the classical anomalies reported for N400 in schizophrenia patients: greater amplitude for related words and lack of N400 effect. Analyses of the correlations between N400 effect and various symptoms of schizophrenia (formal thought disorder, positive symptoms, negative symptoms, overall symptoms, mean neuroleptic dose) or socioeducational data (age, vocabulary level, number of years of study) revealed that only the correlation with formal thought disorder was significant: the higher the scores for formal thought disorder, the lower the N400 effect observed.     

Formal thought disorder in first-episode psychosis

Formal thought disorder (FTD) is one of the fundamental symptom clusters of schizophrenia and it was found to be the strongest predictor determining conversion from first-episode acute transient psychotic disorder to schizophrenia. Our goal in the present study was to compare a first-episode psychosis (FEP) sample to a healthy control group in relation to subtypes of FTD. Fifty six patients aged between 15 and 45 years with FEP and forty five control subjects were included in the study. All the patients were under medication for less than six weeks or drug-naive. FTD was assessed using the Thought and Language Index (TLI), which is composed of impoverishment of thought and disorganization of thought subscales. FEP patients showed significantly higher scores on the items of poverty of speech, weakening of goal, perseveration, looseness, peculiar word use, peculiar sentence construction and peculiar logic compared to controls. Poverty of speech, perseveration and peculiar word use were the significant factors differentiating FEP patients from controls when controlling for years of education, family history of psychosis and drug abuse.     

Cognitive disturbances in chronic schizophrenia: formal thought disorder and basic symptoms

We investigated 37 chronic schizophrenic patients with two objective rating scales (AMDP and Brief Psychiatric Rating Scale; BPRS) and compared the questioned symptoms with the Frankfurter Beschwerde Fragebogen (FBF), a questionnaire for subjective complaints which are close to the uncharacteristic 'basic' symptoms of schizophrenic patients. It was pointed out that the questions in the FBF relate mainly to uncharacteristic symptoms like disturbances of perception, concentration, attention, perceiving, and memory. These subjective symptoms of the FBF show a few correlations with the AMDP/BPRS rating. The total score of the FBF gave no further information about social functioning of patients with cognitive disturbances.     

Neurocognitive correlates of therapeutic alliance in schizophrenia

Although therapeutic alliance in schizophrenia has been linked with treatment adherence and outcome, less is known about its clinical correlates. This study explored neurocognition as a possible predictor of perceived therapeutic alliance among people with schizophrenia in cognitive behavior therapy. Twenty-four participants with schizophrenia spectrum disorders and their therapists were administered the Working Alliance Inventory, Short Form after 3 months of therapy. Totals for clients and therapists were correlated with measures of verbal memory, premorbid intelligence, visual spatial reasoning, executive function, and attention, all obtained before beginning therapy. Poorer performance on verbal memory was significantly related to client report of stronger alliance, whereas better performance on visual spatial reasoning was significantly related to therapist report of stronger alliance. Client and therapist ratings of therapeutic alliance were significantly and positively related. Clients' abilities may differentially affect therapist and client perception of therapeutic alliance in schizophrenia.     

Associating semantic space abnormalities with formal thought disorder in schizophrenia: use of triadic comparisons

Recent studies of schizophrenia have suggested that thought disorder results from abnormalities in semantic processing. In the following pilot study, the cognitive system used for organizing and associating concepts was examined using a triadic comparison task. The semantic maps of schizophrenia patients with high thought disorder (N = 5) were compared to that of schizophrenia patients with low levels of thought disorder (N = 5) and normal controls (N = 10) with multidimensional scaling analysis. At initial testing and at retest, patients with high levels of thought disorder exhibited consistently lower semantic goodness of fit scores and failed to map results of triadic comparisons along well-defined dimensions. Results suggest that thought disorder in schizophrenia is related to a disturbance in the organization of semantic networks.     

Neurocognitive correlates of schizotypy in first degree relatives of schizophrenia patients

We examined neurocognitive correlates of three dimensions of schizotypy in 63 healthy first degree relatives of schizophrenia patients. Neurocognitive measures of attention, verbal memory, and prefrontal functioning were combined with self-report and interview measures of schizotypy. State-psychopathology (anxiety and depression) was a strong predictor for positive schizotypy (PS) and negative schizotypy (NS). PS was slightly correlated to verbal long-term memory, therefore weakly supporting the hypothesis that temporal-limbic malfunctioning underlies PS. NS was not correlated to any prefrontal measure, and therefore no evidence was found for the hypothesis that prefrontal malfunctioning underlies NS. Disorganization schizotypy (DS) was strongly correlated to the false alarm variable of the Continuous Performance Test (CPT), probably supporting the hypothesis of orbitofrontal malfunctioning underlying DS. This correlational pattern of DS echoes closely two schizophrenia studies reporting a relationship between formal thought disorder and the false alarm CPT variable. This similarity, across schizophrenia and relatives samples, may be considered as evidence that false alarms on the CPT and (subtle) problems in goal directedness of thinking are indicators of a genetically determined vulnerability to schizophrenia.     

Abnormal object recall and anterior cingulate overactivation correlate with formal thought disorder in schizophrenia.

BACKGROUND: The neural basis of formal thought disorder (FTD) is unknown. An influential theory is that FTD results from impaired semantic memory processing. We explored the neural correlates of semantic memory retrieval in schizophrenia using an imaging task assessing semantic object recall. METHOD: Sixteen healthy control subjects and sixteen schizophrenia patients whose FTD symptoms were measured with the Thought Disorder Index completed a verbal object-recall task during functional magnetic resonance imaging. Participants viewed two words describing object features that either evoked (object recall) or did not evoke a semantic concept. RESULTS: Schizophrenia patients tended to overrecall objects for feature pairs that did not describe the same object. Functionally, rostral anterior cingulate cortex (ACC) activation in patients positively correlated with FTD severity during both correct recalled and overrecalled trials. Compared with control subjects, during object recalling, patients overactivated bilateral ACC, temporooccipital junctions, temporal poles and parahippocampi, right inferior frontal gyrus, and dorsolateral prefrontal cortex, but underactivated inferior parietal lobules. CONCLUSIONS: Our results support impaired semantic memory retrieval as underlying FTD pathophysiology. Schizophrenia patients showed abnormal activations of brain areas involved in semantic memory, verbal working memory, and initiation and suppression of conflicting responses, which were associated with semantic overrecall and FTD.     

Neurocognitive performances in participants of at-risk mental state for schizophrenia and in first-episode patients

As suggested by the neurodevelopmental model, neurocognitive disturbances are core features of schizophrenia spectrum disorders. The aim of the present study was to explore the neurocognitive performance of symptomatically defined high-risk participants as well as first-episode patients on tests of verbal memory, executive functioning, working memory, and attention. The sample consisted of 54 participants at risk for schizophrenia and 37 patients with a first episode of psychosis. The high-risk group exhibited a similar cognitive performance profile to that of the first-episode participants when compared with normative data. The neurocognitive functioning of both patient groups were within standard average range at most of the cognitive domains. Moreover the intellectual functioning of both groups was within higher average level, while decreased "hit rates" could be observed within both subtests "Figures" and "Symbols" of the Continuous Performance Test-Identical Pairs Version (CPT-IP) in the group of first-episode patients. Direct comparison between the clinical groups did show increasing impairments of these parameters in first-episode patients compared to high-risk participants. Results suggest that high-risk participants do perform at average neurocognitive performance levels at all tested domains compared with normative data. Compared to norm values first-episode patients showed decreased attention abilities.     

Increased positive thought disorder with illness duration in patients with schizophrenia

It is unclear whether the severity of positive formal thought disorder, a core clinical feature of schizophrenia, is stable or worsening through the chronic course of the illness. The neurocognitive basis for positive thought disorder also remains unclear. The aim of the present paper was to examine the relationship between thought disorder as measured by the Thought Disorder Index (TDI) and duration of illness and neuropsychological indices in 79 patients with schizophrenia. TDI scores increased in proportion to illness duration. TDI scores were not associated with verbal memory or executive functioning. These results indicate an ongoing worsening of positive thought disorder through the course of illness in schizophrenia.