Empirical assessment of the factorial structure of clinical symptoms in schizophrenia: negative symptoms.

The factor structure of the Scale for the Assessment of Negative Symptoms (SANS) was examined in a confirmatory factor analysis that used the LISREL procedure. Four models of negative symptom factors were tested in 130 hospitalized schizophrenic patients. A three-factor model of diminished expression, social dysfunction, and disorganization generated by the authors yielded a superior fit to the data relative to the two-factor model of Liddle (1987b) and a unifactorial severity model. A four-factor model based on the original subscale formulation of the SANS failed to fit the data.     

Communication deficits and formal thought disorder in schizophrenic children.

This study examined 31 schizophrenic children to determine if they used discourse devices that make speech coherence differently from sex and mental age matched normal children. It also investigated whether the discourse deficits of the schizophrenic children were related to clinical measures of formal thought disorder. Using Halliday and Hassan's analysis of cohesion, the authors found that schizophrenic children underutilize some discourse devices and overutilize others. Several of their discourse deficits were similar to those described in schizophrenic adults. The schizophrenic children, however, also had additional discourse deficits, which probably reflect developmental delays. The authors also demonstrated that the schizophrenic children with loose associations had different discourse deficits and discourse/IQ correlates than schizophrenic children without loose associations. The schizophrenic children receiving neuroleptic medication had lower loose associations scores than the unmedicated subjects. The authors discuss the possible confounding effect of medication and loose associations, as well as the developmental, cognitive, and clinical implications of the study's findings.     

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.     

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.     

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.     

人格障碍评估量表在精神分裂症患者中的临床应用

目的探讨人格障碍评估（PDA）在精神分裂症患者中的临床应用价值。方法用PDA和PDQ-4^＋分别对39例精神分裂症患者和80例正常人进行评估。结果在PDA中,精神分裂症组的9种类型的人格障碍项目分和总分均高于正常组,都达到极显著性差异,精神分裂症组各人格障碍类型的发生率分布中,C类群占有相当的比例,其中回避型占53．85％,强迫型占41．02％,A类群中,偏执型占18．42％,在PDQ-^4＋中,也是回避型和强迫型所占的比例最高,分别为42．10％,和36．80％,在因素分析中,采用主成份分析及方差极大旋转的方法,提取了3个公因子,它们的方差累计贡献率为63．54％,旋转前的因子距陈显示9个分量表都有中等以上的负荷。结论PDA可反映出精神分裂症患者的人格障碍共病情况,有临床应用价值。     

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.     

The specificity of schizophrenic thought disorder.

Bannister and Salmon (1966), in a repertory grid study, reported that 'thought-disordered schizophrenics lost significantly more reliability and social agreement when shifted from object to people construing than normal'. This conclusion is of doubtful validity, since the between-grids variable, people vs. objects, was confounded with at least five other variables of possible relevance, three of which have been found by subsequent workers (McPherson & Buckley, 1970; Williams, 1971; Heather, 1976) to affect performance on grids. The main aim of the present experiment was to determine the effects of as many as possible of these variables. The subsidiary aim was to replicate, or otherwise, the findings of Frith & Lillie (1972) and Haynes & Phillips (1973) that the effective discriminator between thought-disorder schizophrenics and other groups on repertory grid tests is not intensity of relationship between constructs but pure (element or internal) consistency. Six grids involving all feasible combinations of rating familiar and unfamiliar people and objects on psychological and physical constructs were administered to 10 thought-disordered schizophrenics, 10 non-thought-disordered schizophrenics and 10 normals. As regards the main aim of the experiment it was found that there was no significant grids x diagnoses interaction on pure consistency, but that there was one on intensity, even with pure consistency partialled out. Taking previous work into consideration, it appears that this effect is weak, inconsistent from experiment to experiment, and anomalous in the present study. As regards the subsidiary aim, the findings of the two previous experiments cited above were confirmed. The discrepant results of McPherson et al. (1973) are considered, and it is noted that they held only for a subsample of the schizophrenic group in that experiment, the results for the total sample of schizophrenics, manics and depressives not being inconsistent with those of other experiments. The theoretical and practical implications of these and previous finding are indicated.     

Cerebral correlates of selective attention in schizophrenic patients with formal thought disorder: a controlled H2 15O-PET study

There is a widespread belief that formal thought disorders may be associated with disturbed selective attention in schizophrenia. Two hypotheses are derived: (1) patients with slightly pronounced formal thought disorders should differ from those with severely expressed formal thought disorders in terms of selective attention; and (2) the cerebral correlates of selective attention should be organised differently in mildly versus severely thought-disordered patients. We compared 20 female schizophrenic patients, one-half with mild, one-half with obvious formal thought disorders, and 10 control subjects on a neuropsychological battery and a cognitive activation task for selective attention (Go/NoGo) for the assessment of rCBF using H2 15O-PET. While the first hypothesis has not been confirmed, we found that the cerebral regions activated by selective attention in the two patient groups showed completely differing organisations. Low degrees of formal thought disorders were associated with significant activations in frontal superior gyrus and ventral anterior thalamic nucleus whereas high degrees of formal thought disorders were accompanied by significant activations in fusiform gyrus and precuneus. We suggest that differing task-solving strategies are applied by both clinical subgroups to achieve comparable results on the selective attention paradigm.     

Eating disorder symptoms among female anxiety disorder patients in clinical practice: the importance of anxiety comorbidity assessment

This exploratory study investigated the relationship between anxiety disorders, anxiety comorbidity, and eating disorder (ED) symptoms in clinical practice, and examined the naturalistic detection of ED when diagnoses were based on the Anxiety Disorders Interview Schedule (ADIS). Two hundred and fifty-seven female patients completed an ED questionnaire and were assessed with the ADIS. Although ED frequency did not differ among anxiety disorder diagnoses, regression analyses revealed that social phobia (SP) and posttraumatic stress disorder (PTSD) accounted for unique variance in eating pathology. Questionnaire results indicated that almost 12% of patients met criteria for a possible ED. Clinicians using the ADIS evidenced good specificity but were not sensitive to detecting ED, missing 80% of possible cases. Results support possible links between ED, social phobia and PTSD and highlight the importance of assessing anxiety comorbidity when examining the relationship between ED and anxiety disorders. Results also suggest that formal screening for ED among female anxiety patients may be warranted.     

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.     

Processes underlying formal thought disorder in psychiatric inpatients

Three theories about the cognitive processes underlying symptoms of formal thought disorder in psychiatric inpatients were tested. Chapman and Chapman's "excessive yielding to normal bias" theory and a response competition theory were tested by using two ambiguity tasks. Chapman and Chapman's bias theory predicts a smaller ambiguity effect for thought-disordered patients; a response competition hypothesis predicts a larger ambiguity effect. Results showed no difference between thought-disordered and non-thought-disordered patients. To test a distractibility theory of thought disorder, subjects performed a Stroop-type task in which they counted the number of digits (e.g., 3333) or symbols (####) in a set. Thought-disordered patients did show an increased effect of the presence of the digits, and this finding was replicated in a second inpatient sample. Thus, results were consistent with the distractibility theory and with a reformulation of the bias theory, in which the bias shown by thought-disordered patients is not a tendency toward a particular response, but rather toward a particular rule, or set, for responding.     

The early course of schizophrenic thought disorder

The current investigation studied the early course of positive thought disorder and its relationship to other aspects of schizophrenic outcome. Forty-eight schizophrenics diagnosed using the Research Diagnostic Criteria (RDC), 51 psychotic nonschizophrenics, and 67 nonpsychotic patients were studied at index hospitalization and at a 1.5-year followup. Most thought-disordered schizophrenics and other psychotic patients showed some reduction in thought pathology between index hospitalization and followup (p less than .02). A larger percentage of schizophrenics than other psychotic and nonpsychotic showed thought disorder at the acute phase and at followup assessment (p less than .05), although only a subgroup of 27 percent of the schizophrenics showed severe thought disorder at followup. At followup, severely thought-disordered schizophrenics showed residual signs of psychosis and poor functioning in other areas. Positive thought disorder in schizophrenics at followup most often occurred within the context of an unremitted illness and was less frequently due to a new, acute episode of disturbance. Continuously thought-disordered schizophrenics exhibited more severe impairments in life adjustment at 1.5-year followup than did episodic or nonthought-disordered schizophrenics (p less than .02). The results suggest that severe thought disorder is a persistent characteristic in a subgroup of early schizophrenics.     

Age-of-onset of schizophrenic and obsessive-compulsive symptoms in patients with schizo-obsessive disorder

Obsessive-compulsive symptoms (OCS) are prevalent, persistent, clinically significant phenomena in schizophrenia. To facilitate the understanding of their temporal interrelationship, we assessed age-of-onset of schizophrenic and obsessive-compulsive symptoms among 133 patients admitted to Tirat Carmel Mental Health Center (Israel) during the years 1999-2010 who met DSM-IV criteria for both schizophrenic disorder and obsessive-compulsive disorder (OCD). The mean age-of-onset of the first clinically significant OCS was significantly earlier than the mean age-of onset of the first psychotic symptoms. An earlier onset of OCS was detected in men, but not in women. In sixty-four of 133 patients OCS preceded the first psychotic symptoms, in 37 patients OCS followed them, and in 32 patients OCS and psychotic symptoms occurred simultaneously. A sub-analysis of 52 first-episode schizophrenia patients revealed that OCS emerged approximately 3 years earlier than psychotic symptoms. Notably, schizo-obsessive patients had earlier mean age-of-onset of first psychotic symptoms than a comparative group of 113 non-OCD schizophrenia patients matched for age, gender and number of hospitalization. Earlier emergence of OCS than schizophrenic symptoms in schizo-obsessive patients suggests that they are independent of psychosis and are not consequent to schizophrenia. In addition, the presence of OCS seems to modify clinical features of schizophrenia accounting for earlier onset of first psychotic symptoms, however a replication of these findings is needed.     

Empirical evaluation of the factorial structure of attention in adolescent psychiatric patients

Abstract

Adolescent psychiatric inpatients (N = 278) were examined with a structured battery of measures of attentional functioning. The factorial structure of the attentional performance was then examined through confirmatory factor analysis (CFA). Two conceptually related models of attentional functioning were compared to null and unifactorial comparison models. One of the conceptual models, previously described in a series of studies by Mirsky, separates attentional functions into four factors and the other conceptual model, developed by the present authors, collapses two of Mirsky's factors into one. Both of the substantive models fit the data with the four-factor model failing to improve substantially on the simpler three-factor model. These data provide support for the validity of the Mirsky model of attention and suggest that these factors merit further research to validate the brain localization hypotheses that underlie them.     

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.