Self-perceived cognitive functioning does not correlate with objective measures of cognition in schizophrenia

Background

Growing interest in the study of self-perceived cognitive deficits in schizophrenia has been recently observed. The authors validated in a previous study the Subjective Scale To Investigate Cognition into Schizophrenia Tunisian Arabic Version (SSTICS_tun_arab), a self-questionnaire established to collect cognitive complaints in patients with schizophrenia.

Objective

The aim of the present study was to explore the relationship between the SSTICS_tun_arab scores and objective cognitive performances.

Methods

One hundred four patients with schizophrenia spectrum disorders were administered measures of the Positive and Negative Syndrome Scale, the Global Assessment Functioning Scale, and the Calgary Depression Scale as well as measures of the SSTICS_tun_arab and a cognitive battery.

Results

No correlations were found between objective neuropsychologic performances and scores of the SSTICS_tun_arab.

Conclusions

Our findings support the hypothesis of independence of self-perceived cognitive functioning from objective neuropsychologic deficits in schizophrenia. They also suggest that insight of mental illness seems to be not a unitary concept but more likely to be divided in different aspects including cognitive insight.     

Cognitive functioning in first-episode schizophrenia

OBJECTIVE: To compare the cognitive functioning of a sample of patients experiencing their first episode of schizophrenia with that of patients with an established schizophrenia illness. DESIGN: Cross-sectional and longitudinal study. SETTING: The Calgary Early Psychosis Treatment and Prevention Program and an outpatient clinic in a department of psychiatry at a university-affiliated hospital. PARTICIPANTS: One hundred and eleven patients who were experiencing their first episode of schizophrenia and 76 outpatients with an established schizophrenia illness. MEASURES: The Positive and Negative Syndrome Scale for schizophrenia was administered to all subjects to determine levels of positive and negative symptoms. Executive functioning, information processing, visual memory, and immediate and delayed verbal memory were assessed. RESULTS: There were limited differences between the 2 groups in terms of cognitive functioning. Although the first-episode patients demonstrated generally superior scores, their performance was impaired. CONCLUSIONS: These results support the findings of previous studies suggesting that first-episode patients demonstrate cognitive impairments similar to those of patients with an established schizophrenia illness.     

精神分裂症首次发病患者及其健康同胞认知功能的比较研究

目的 比较精神分裂症首次发病患者与健康同胞及正常对照认知功能的差异,探讨精神分裂症在认知功能领域的内表型.方法 采用目前常用的范畴流畅测验(CFT)、数字符号编码测验(DSCT)、连线测验(TMT)、韦克斯勒记忆量表第3版(WMS-Ⅲ)空间广度测验(WMS-ⅢSST)、霍普金斯词汇学习测验-修订版(HVLT-R)、简易视觉空间记忆测验-修订版(BVMT-R)、定步调听觉连续加法测验(PASAT)和威斯康星卡片分类测验-64(WCST-64)对92例精神分裂症首次发病患者(患者组)、56例健康同胞(同胞组)和62名健康对照者(对照组)的认知功能进行检测.结果 (1)患者组所有神经心理测验成绩均差于对照组,差异有统计学意义(P＜0.01).(2)同胞组的CFT、DSCT、TMT、HVLT-R即刻记忆和延迟记忆、BVMT-R即刻记忆、PASAT、WCST-64持续错误数、持续反应数和完成分类数的测验成绩差于对照组,差异有统计学意义(P＜0.05).(3)患者组与同胞组的CFT、WCST-64中的持续错误数、持续反应数和完成分类数测验成绩分别为(18.40±12.12)分比( 18.86±5.19)分、(16.48±8.19)分比(14.80±5.86)分、(18.76±10.91)分比(16.86 ±7.73)分、(1.33±2.81)分比(1.63±1.36)分,2组比较差异无统计学意义(P＞0.05),其他神经心理测验成绩比较,患者组差于同胞组,差异有统计学意义(P＜0.05).结论 精神分裂症首次发病患者存在处理速度、工作记忆、言语记忆、空间记忆、注意警觉和执行功能广泛性的认知功能损害,精神分裂症健康同胞存在处理速度、言语记忆、视觉记忆、注意警觉、执行功能的认知缺陷;语义流畅性功能和执行功能可能是精神分裂症的潜在内表型.     

Cognitive functioning in the early course of first-episode schizophrenia spectrum disorders

OBJECTIVE: The aim of this study was to examine possible cognitive changes throughout the early course of schizophrenia spectrum disorders. METHOD: Forty-two patients, aged 15-50 years, admitted to a first episode psychosis program (PAFIP) serving to the community of Cantabria (Spain) and 43 healthy volunteers completed a brief battery of five neurocognitive tests at four time-points over 3 months. The cognitive testing comprise five domains: attention, visuomotor speed, declarative memory, working memory and executive function. Baseline assessment occurred within 72 hour after the initiation of standard pharmacological treatment, and after then parallel forms of the tests were applied at week-2, week-6, and month-3. RESULTS: Patient scores showed a significant impairment compared to healthy volunteers in the five cognitive domains at baseline and week-2 assessments. After the first 3 months of antipsychotic treatment, the patient group performance reached healthy volunteers level on executive function (Stroop interference) and immediate verbal memory tests. In contrast, performance on working memory, sustained attention, visuomotor speed, and verbal memory delayed recall domains still remained below healthy volunteers, although visuomotor processing speed showed a significant improvement. CONCLUSION: Schizophrenia spectrum patients show heterogeneous patterns and degrees of cognitive changes that contribute to stress the importance of when, what, and how neurocognitive functioning in the early phases of the illness is evaluated.     

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.     

Phenomenology and functioning in first-episode schizophrenia.

One current view of schizophrenia is that its clinical and functional features show a deteriorating course, particularly for negative symptoms. However, this is difficult to study in chronic patients who have been exposed to pharmacologic treatment and institutionalization. Examining first-episode (FE) patients can help clarify which symptoms are present initially and how the symptom pattern is linked to functioning. We evaluated a sample of 37 FE patients with schizophrenia and compared them to 70 other schizophrenia (OS) patients on standard clinical scales, measures of premorbid functioning, and quality of life. FE patients showed a symptom profile similar to OS patients; in particular, there was no evidence that negative symptoms are less severe in the FE group. Analysis of the clinical data led us to the conclusion that the symptom profile of schizophrenia exists at the outset, that negative symptoms are associated with poor premorbid and current functioning, but that the role of positive symptoms is more complex and may vary in subtypes.     

Subjective cognitive complaints versus objective neuropsychological performance in older adults with epilepsy

Memory complaints are common among older adults with epilepsy (OAE), though discrepancy between subjective complaints and objective performance often exists. This study examined how accurately OAE and their informants reported on the participant's cognitive difficulties by comparing ratings of everyday cognition to objective performance. Thirty-seven OAE and 27 older adult controls completed a brief battery of neuropsychological tests, the Beck Depression Inventory, and the Cognitive Difficulties Scale (CDS). Each participant had an informant who completed the CDS. Older adults with epilepsy performed worse than controls on cognitive testing and reported more subjective cognitive complaints. Neither participant- nor informant-reported cognitive complaints were related to performance on any of the neuropsychological tests for either the group with epilepsy or control group, but both were related to greater depressive symptoms. Results suggest that subjective report of cognitive problems by both OAE and their informants may not reliably reflect the extent to which these problems exist.     

Prefrontal cognitive functions in stabilized first-episode patients with schizophrenia spectrum disorders: a dissociation between dorsolateral and orbitofrontal functioning

Specific prefrontal cognitive impairments have been reported in first-episode and chronic schizophrenia. We sought to investigate potential impairments in specific prefrontal cortical cognitive functions among stabilized patients with a first-episode of schizophrenia. A sample of 80 individuals with a first-episode of schizophrenia spectrum disorders and 22 healthy volunteers underwent a neurocognitive battery assessing orbitofrontal (OFC) [The Iowa Gambling Task (GT)], and dorsolateral prefrontal (DLPFC) functions (WAIS III Backward digits, verbal fluency test (FAS), and Trail Making Test). Cognitive data were obtained following stabilization of acute psychotic symptoms. Clinical symptoms after six weeks of treatment were assessed by using the SAPS and SANS scales. While there were no significant group differences in overall scores and in the profile of progress of performance along periods on the GT, patient group showed a significant impairment when performing DLPFC tasks. Only FAS score was correlated to the severity of negative symptomatology. The OFC functions are unimpaired at the early phases of psychosis and in contrast there is a significant deficit in DLPFC functions in first-episode of schizophrenia.     

儿童精神分裂症的认知功能

目的 :探讨儿童精神分裂症患者认知功能障碍的特点。　方法 :采用中国 韦氏儿童智力量表 (C WISC)对 4 1例 13～ 16岁儿童精神分裂症患者进行测试 ,其结果与常模相比较。　结果 :全量表智商为 (80 .0 0± 17.2 1)分 ,操作智商为 (6 7.4 1± 2 0 .89)分 ,言语智商为 (92 .5 1± 17.5 4 )分。 3种智商 <89及 <6 9者所占的百分比分别与常模比较 ,差异均具有显著性。　结论 :儿童精神分裂症患者智商多低于正常 ,以操作智商损伤为主 ,言语智商与操作智商明显不平衡。     

精神分裂症患者认知功能与社会功能的相关性

目的探讨精神分裂症恢复期患者认知功能对社会功能的影响。方法对80例精神分裂症恢复期患者采用瑞文标准测验（CRT）、韦氏成人智力量表（WAIS）、威斯康星卡片测验（WCST）,分别与社会功能缺陷量表（SDSS）进行多重线性回归分析。结果经逐步回归分析显示,WCST中变量（正确反应数、持续错误数、分类数）、WAIS中言语量表分、CRT中瑞文总分进入回归方程,拟合的回归方程均有统计学意义。其中瑞文总分、言语量表分与SDSS呈线性负相关关系,持续错误数与SDSS呈线性正相关关系;比较WCST、CRT、WAIS与SDSS的相关性,回归模型的拟合最好的为WCST。结论精神分裂症患者的认知功能与社会功能有显著相关性,正确的评测及改善认知功能对提高患者的社会功能有重要意义,WCST提供了一个有效预测精神分裂症患者社会功能的重要方法。     

The cognitive aspect of formal thought disorder and its relationship with global social functioning and the quality of life in schizophrenia

Purpose

It was expected that using a comprehensive scale like the Thought and Language Disorder Scale (TALD) for measurement of FTD would enable assessing its heterogeneity and its associations with cognitive impairment and functionality. This study has aimed to analyze the relationship between formal thought disorder (FTD) and cognitive functions, functionality, and quality of life in schizophrenia.

Methods

This cross-sectional exploratory study included 46 clinical participants meeting the DSM-5 diagnostic criteria for schizophrenia and 35 healthy individuals as the control groups. Data were acquired by means of the Turkish language version of the TALD, the Positive and Negative Syndrome Scale, the Clinical Global Impression Scale, the Functioning Assessment Short Test, the Social Functioning Scale, the World Health Organization Quality of Life Instrument-Short Form, and a neuropsychological test battery on executive functions, working memory, verbal fluency, abstract thinking, and response inhibition. Correlation analyses were conducted to detect significant relationships.

Results

The clinical group scored failures in all cognitive tests. The objective positive FTD was associated with deficits in executive functions and social functioning. The objective negative FTD was associated with poor performance in all cognitive domains, physical quality of life, and social and global functioning. The subjective negative FTD was negatively correlated with psychological quality of life.

Conclusion

This study demonstrated that objective FTD factors reflect different underlying cognitive deficits and correlate with different functioning domains. Significant correlation was determined between subjective negative FTD and psychological quality of life. Given the close relationship of FTD with functioning and quality of life, the FTD-related cognitive deficits should be the key treatment goal in schizophrenia.

     

Subjective and objective quality of life in schizophrenia

OBJECTIVE: Quality of life (QOL) is considered an important outcome in the treatment of schizophrenia, but the determinants of QOL are poorly understood in this population. Furthermore, previous studies have relied on combined measures of subjective QOL (usually defined as life satisfaction) and objective QOL (usually defined as participation in activities and relationships). We examined separately the clinical, functional, and cognitive predictors of subjective and objective QOL in outpatients with schizophrenia. We hypothesized that better subjective QOL would be associated with less severe negative and depressive symptoms, better objective QOL, and greater everyday functioning capacity, and that better objective QOL would be associated with less severe negative and depressive symptoms, better cognitive performance, and greater functional capacity. METHOD: Participants included 88 outpatients with schizophrenia or schizoaffective disorder who completed a comprehensive series of assessments, including measures of positive, negative, and depressive symptoms; performance-based functional skills; a neuropsychological battery; and an interview measure of subjective and objective QOL. RESULTS: In the context of multiple predictor variables, more severe depressive symptoms and better neuropsychological functioning were independent predictors of worse subjective QOL. More severe negative symptoms predicted worse objective QOL. Functional capacity variables were not associated with subjective or objective QOL. CONCLUSION: Treatments to improve QOL in schizophrenia should focus on negative symptoms and depressive symptoms.     

Subjective cognitive dysfunction in first-episode and chronic schizophrenic patients

Previous studies indicate that first-episode and chronic schizophrenic patients do not differ regarding neuropsychological performance as assessed with standard cognitive tasks. For the present study, it was investigated whether first-episode and chronic schizophrenics report similar subjective cognitive deficits. The Frankfurt Complaint Questionnaire (FCQ), a scale devised for assessing subjective cognitive disturbances in schizophrenia, was administered to 20 first-episode and 36 chronic schizophrenic patients, as well as 20 healthy controls. The schizophrenic subsamples did not differ on any of the FCQ subscales or on a "lie scale," measuring illness denial. Psychopathological ratings were comparable for both groups. As expected, healthy subjects reported significantly less cognitive and perceptual problems than schizophrenic patients. In marked contrast to a Kraepelinian view of schizophrenia, the present data confirm previous studies conducted with objective neuropsychological tests that schizophrenia is a neurodevelopmental rather than a neurodegenerative disorder.     

Cognitive functioning in adolescents with schizophrenia spectrum disorders

Patients with schizophrenia have deficits in executive function that involve attentional set-shifting and planning ability. It is unclear, however, whether such deficits are stable during the course of the illness or if they fluctuate in response to medication effects or symptom changes. Patients with a DSM-IV diagnosis of schizophrenia (n=28) and healthy control subjects (n=17) were tested on computerised measures of attentional set-shifting and planning at baseline and 9-month follow-up. The measures used were the Intra/Extradimensional Shift test (ID/ED) and the Stockings of Cambridge test (SoC) from the Cambridge Automated Neuropsychological Testing Battery (CANTAB). On both tests, the patients were poorer than controls at baseline; however, there was no evidence of change over the 9-month follow-up. Additionally, there was little evidence of a relationship between executive test performance and medication or length of illness. This study accords with the presence of executive processing deficits in schizophrenia that are stable across time.     

The relationship of early premorbid adjustment with negative symptoms and cognitive functions in first-episode schizophrenia: A prospective three-year follow-up study

Premorbid adjustment is an important prognostic factor of schizophrenia. The relationships between sub-components of premorbid adjustment and outcomes on symptoms and cognition in first-episode schizophrenia were under-studied. In the current study, we prospectively followed up 93 patients aged 18–55 years presenting with first-episode schizophrenia-spectrum disorder. Psychopathological and cognitive assessments were conducted at baseline, clinical stabilization, 12, 24 and 36 months. Premorbid adjustment was sub-divided into discrete functional domains, developmental stages and premorbid-course types based on ratings of the Premorbid Adjustment Scale (PAS). The study focused on early developmental stages to minimize contamination by prodromal symptoms. Results indicated that gender differences in premorbid functioning were primarily related to early-adolescence adjustment and academic domain. Social domain was more strongly related to negative symptoms, while academic domain was more consistently linked to cognitive outcome (Wisconsin Card Sorting test and verbal fluency). Patients with stable-poor premorbid course had more severe negative symptoms and cognitive impairment. In conclusion, in a Chinese cohort of first-episode schizophrenia-spectrum disorder, sub-components of early premorbid adjustment were shown to be differentially related to clinical and cognitive measures. The results highlighted the importance of applying a more refined delineation of premorbid functioning in studying illness outcome.     

Self-assessed cognitive dysfunction and objective performance in outpatients with schizophrenia participating in a rehabilitation program

OBJECTIVE: To explore the pattern of associations between self-assessed and objective neuropsychological performance in a sample of outpatients with schizophrenia participating in a rehabilitation program. METHOD: The Subjective Scale to Investigate Cognition in Schizophrenia (SSTICS) [Compr. Psychiatry 44 (2003) 331] was used to assess cognitive complaints in 73 subjects with schizophrenia. Visuo-spatial tests of the Cambridge Neuropsychological Test Automated Battery (CANTAB) [Cogn. Neuropsychiatry 3 (1998) 45] were administered as objective measures. RESULTS: Cognitive complaints in several cognitive domains were mainly correlated with a true difficulty in memory. Higher SSTICS attention scores, i.e. increased complaints, were associated with poorer CANTAB explicit visual memory and planning performances. Higher SSTICS executive functioning scores were associated with poorer CANTAB explicit visual memory scores. CONCLUSION: These findings suggest that outpatients with schizophrenia express some cognitive difficulties. However, the cognitive nature of these subjective complaints does not strictly correspond with objective performances. These results also suggest that theoretical constructs of cognitive functions do not always have ecological validity. Thus, subjective cognitive complaints should be taken into account in assessment of patient well-being, but cannot be used as a substitute to objective cognitive measures. The simultaneous use of subjective and objective measures of cognitive dysfunction may provide a more complete picture of individual rehabilitation targets in patients with schizophrenia.     

Subjective preference for lamotrigine or topiramate in healthy volunteers: relationship to cognitive and behavioral functioning

OBJECTIVE: Outcomes research emphasizes patient self-assessment and preferences in optimizing treatment. We previously showed that lamotrigine produces significantly less cognitive and behavioral impairment compared with topiramate. In the current study we extend these observations to subject self-report of preference for lamotrigine or topiramate independent of potentially confounding effects of seizures or seizure control. Additionally, drug preference was related to effects of lamotrigine and topiramate on objective neuropsychological tests as well as self-perception on behavioral instruments. METHODS: Thirty-seven healthy volunteers completed a double-blind, randomized crossover design incorporating two 12-week treatment periods of lamotrigine and topiramate each titrated to a dose of 300 mg/day. Evaluation of 23 objective neuropsychological and 15 subjective behavioral measures occurred at four times: pretreatment baseline, first treatment, second treatment, and posttreatment baseline. Preference for lamotrigine or topiramate was assessed, while blinding was maintained, at the final study visit when each subject was asked which drug he or she would prefer to take. RESULTS: A large majority (70%) preferred lamotrigine, 16% stated preference for topiramate, and 14% had no preference (drugs equivalent). Consistent with preference, those preferring lamotrigine performed better on 19 of 23 objective and 13 of 15 subjective behavioral measurements while on lamotrigine. Inconsistent with preference, subjects preferring topiramate performed better on 19 of 23 objective and 9 of 15 subjective behavioral measures while on lamotrigine. Topiramate preference also did not correlate with IQ, serum concentration, body mass index, age, or gender. Topiramate preference did relate to responses on the Profile of Mood States. CONCLUSION: Lamotrigine was preferred by the majority of subjects, congruent with objective neuropsychological and subjective behavioral measures. In contrast, for those stating a preference for topiramate the results on objective neuropsychological measures were impaired while fewer complaints were noted on the Profile of Mood States. This suggests that preference for topiramate may be determined by an effect on mood.