Exploring cognitive complaints in schizophrenia: the subjective scale to investigate cognition in schizophrenia

While it has become commonplace to test the various components of memory in schizophrenia with paper-and-pencil or in-lab tasks, very little data exist on the subjective complaints of patients regarding their memory. Few instruments have been designed to collect systematically the complaints of patients with schizophrenia. We present a work in progress on the Subjective Scale to Investigate Cognition in Schizophrenia (SSTICS), a 21-item, Likert-type scale that is simple and easy to use. It allows a quantitative approach to the subjective and cognitive dimensions of schizophrenia. Stip constructed the scale based on a questionnaire covering several cognitive domains: memory (working memory, explicit long-term memory), attention (divided, distractibility, alertness, sustained), language, and praxia. We evaluated the psychometric properties of the SSTICS in a population of 114 French-speaking patients in Montreal. Patients were recruited in the community and assessed with the Structured Clinical Interview for DSM-III-R (SCID), the Positive and Negative Syndrome Scale (PANSS), and the Extrapyramidal Symptoms Rating Scale (ESRS). Cognition was measured using the Rey Auditory Verbal Learning Test (RAVLT) (long-term memory), Controlled Oral Word Association Test (verbal fluency), and Trails A and B. Preliminary analyses showed very good internal consistency for the global score (alpha=0.88), and alphas varying from 0.57 to 0.72 for the subscales. Stability over time was very good. The principal components analysis accounted for a multiple structure. Correlations between subjective scores and objective cognitive assessment were significant for several domains. Validation of the SSTICS needs to be completed through further exploration of the factorial structure and testing of the English version.     

The crucial role of sustained attention in community functioning in outpatients with schizophrenia

The aim was to explore the pattern of associations between visual cognitive performance and community functioning in a sample of outpatients with schizophrenia participating in a rehabilitation program. Visuo-spatial tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were administered to assess cognitive performances in 88 subjects. The Multnomah Community Ability Scale (MCAS) was used to measure dimensions of community functioning. Our results showed that the sustained attention score was significantly associated with the global community functioning score and with two specific dimensions: "adjustment to living" and "behavioral problems". No association was found between other cognitive indices and MCAS scores. Since the sustained attention task mainly involves the executive component of working memory, these findings suggest that attentional control processes are limiting factors for community functioning in schizophrenia outpatients. Measures of such processes could serve as key indices of disability in clinical practice. Attention and working memory training may be helpful to improve community functioning in subjects with schizophrenia.     

Objective measures of prospective memory do not correlate with subjective complaints in schizophrenia

While a number of studies have shown that individuals with schizophrenia are impaired on various types of prospective memory, few studies have examined the relationship between subjective and objective measures of this construct in this clinical group. The purpose of the current study was to explore the relationship between computer-based prospective memory tasks and the corresponding subjective complaints in patients with schizophrenia, individuals with schizotypal personality features, and healthy volunteers. The findings showed that patients with schizophrenia demonstrated significantly poorer performance in all domains of memory function except visual memory than individuals with schizotypal personality disorder and healthy controls. More importantly, there was a significant interaction effect of prospective memory type and group. Although patients with schizophrenia were found to show significantly poorer performance on computer-based measures of prospective memory than controls, their level of subjective complaint was not found to be significantly higher. While subjective complaints of prospective memory were found to associate significantly with self-reported executive dysfunctions, significant relationships were not found between these complaints and performance on a computer-based task of prospective memory and other objective measures of memory. Taken together, these findings suggest that subjective and objective measures of prospective memory are two distinct domains that might need to be assessed and addressed separately.     

Cognitive predictors of psychosocial functioning outcome in schizophrenia: a follow-up study of subjects participating in a rehabilitation program

The aims of this prospective study were to explore in subjects with psychosis participating in a rehabilitation program whether cognitive performances at baseline predicted (i) psychosocial functioning over a 15-16 month follow-up; (ii) improvement in psychosocial functioning over the rehabilitation program. Visuo-spatial tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were administered to assess cognitive performance in 55 subjects with schizophrenia spectrum disorders who completed a rehabilitation program. The Multnomah Community Ability Scale (MCAS) was used to measure dimensions of community functioning. One subscale of the Client's Assessment of Strengths, Interests, and Goals (CASIG) provided a measure of subjective quality of life (QoL). Improvement was defined as a 15% or more increase in psychosocial scores between baseline and follow-up. Worse baseline sustained attention predicted better self-rated quality of life, and better baseline visual memory predicted better community functioning over the rehabilitation follow-up period, in particular, higher autonomy in activities of daily living, and less physical and psychiatric symptoms that could interfere with rehabilitation. Baseline cognitive performances predicted community functioning improvement during the follow-up period: visual memory predicted improvement in daily living autonomy and in social competence; sustained attention predicted improvement in behavioral problems (such as medication compliance, collaboration with treatment providers or impulse control) and social competence; planning performances predicted improvement in social competence. These cognitive functions could be specifically targeted in a rehabilitation program aimed at enhancing functioning in those particular dimensions.     

L’insight neurocognitif dans la schizophrénie

Objectives

Given the extent, magnitude and functional significance of the neurocognitive deficits of schizophrenia, growing attention has been paid recently to patients’ self-awareness of their own deficits. Thus far, the literature has shown either that patients fail to recognize their cognitive deficits or that the association between subjective and objective cognition is weak in schizophrenia. The reasons for this lack of consistency remain unexplained but may have to do, among others, with the influence of potential confounding clinical variables and the choice of the scale used to measure self-awareness of cognitive deficits. In the current study, we sought to examine the relationships between subjective and objective cognitive performance in schizophrenia, while controlling for the influence of sociodemographic and psychiatric variables.

Subjective memory complaints in an elderly sample: a cross-sectional study

BACKGROUND: Community based studies show that neurological or psychiatric symptoms are very frequent among the elderly population, with poor memory complaints being the most common. However, the relationship between poor memory complaints and objective memory performance is unclear. We designed this study to evaluate whether subjective memory complaints (SMC) are associated with objective cognitive performance or depression amongst the elderly Brazilian generation. METHODS: A cross-sectional study was carried out in 114 patients who were 50+, with or without SMC having no obvious cognitive impairment at its baseline (this was screened by the Mini-Mental State Examination with cut-off values adapted according to the subjects' educational background). Subjects were assessed regarding memory difficulty complaints, demographic data and underwent a neuropsychological assessment made up of nine cognitive tests (Rey Auditory Verbal Learning Test, Visual Reproduction Test, Logic Memory--History A, Free and Cued Selective Reminding Test, Stroop Test, Digit Span, Digit Symbol, Trail Making Test, fluency tests: naming animals and fruits) and the Geriatric Depression Scale. RESULTS: Twenty-one percent of the subjects had subjective memory complaints. The scores in the cognitive assessment of subjects with SMC did not differ from the scores of subjects without SMC. However, patients with subjective memory complaints had lower scores in the fluency test--category animals and the Geriatric Depression Scale. CONCLUSIONS: These results support the finding from other cross-sectional studies showing that subjective memory complaints are associated with depressive symptoms rather than objective cognitive performance.     

Computerized assessment of cognition in schizophrenia: promises and pitfalls of CANTAB.

OBJECTIVE: Over the last decade, the Cambridge Neuropsychological Test Automated Battery (CANTAB), which comprises visuo-spatial tasks, has been utilized in cognitive studies of schizophrenia. A clear approach concerning the usage of CANTAB for the appraisal of neurocognitive dysfunction in schizophrenia is currently lacking. METHOD: In this paper, we have first reviewed the overall applications of CANTAB and then evaluated methodological strengths and weaknesses of CANTAB as a neurocognitive battery for schizophrenia. We carried out a systematic search and assessment of studies where CANTAB was utilized to measure cognitive function in schizophrenia. We have also attempted to quantify the available data and perform a meta-analysis, but this approach turned out to be still premature. RESULTS: CANTAB has enabled researchers to highlight significant deficits affecting broad cognitive domains in schizophrenia, such as working memory, decision-making, attention, executive functions and visual memory. So far, the most consistent deficit observed with CANTAB testing has been attentional set-shifting, suggestive of fronto-striatal dysfunctions. In addition, preliminary evidence points towards the potential use of CANTAB to identify cognitive predictors of psychosocial functioning, to describe the relationships between symptoms and cognition, and to measure the impact of pharmacological agents on cognitive functioning. CONCLUSION: CANTAB has been used successfully to highlight the range of visuo-spatial cognitive deficits in schizophrenia, producing similar results to those obtained with some traditional neuropsychological tests. Further studies validating the use of CANTAB following the standard set by Measurement And Treatment Research to Improve Cognition in Schizophrenia (MATRICS) are warranted.     

Dissociating self-reported cognitive complaint from clinical insight in schizophrenia

Whereas new pharmacological treatments are developed for cognitive impairments in schizophrenia, self-assessment of cognitive dysfunctioning besides their objective validity could be of interest in evaluating patients' motivation to engage in rehabilitation program. Nevertheless insight into symptoms is severely impaired in schizophrenia and is negatively linked with poor compliance. But it is yet unknown if patients with poor insight into their symptoms could have some insight into their cognitive impairments. The aim of this study was to explore the relationships existing between the cognitive complaint and the level of awareness of the disease in patients with schizophrenia. A total of 101 patients with DSM-IV schizophrenia or schizoaffective disorder and 60 control participants were recruited. Insight was assessed using the Scale to assess Unawareness of Mental Disorder (SUMD) and cognitive complaint intensity was assessed with the Scale to Investigate Cognition in Schizophrenia (SSTICS). Participants with schizophrenia displayed the same level of cognitive complaint when compared to healthy controls. Strong correlations were observed between SSTICS total score and duration of illness, levels of depression and state anxiety. Patients with a good insight into the therapeutic effects achieved with medication expressed a more important cognitive complaint. No correlations were found between the four others SUMD insight dimensions and total SSTICS score. The partial overlap of insight into illness and cognitive complaint suggests that insight is modular in schizophrenia. Assessment of cognitive complaint and awareness of illness need to be assessed before engagement in rehabilitation program.     

Processing Speed Mediates Gender Differences in Memory in Schizophrenia

The primary aim of this study was to examine whether processing speed mediates the association between gender and episodic memory in schizophrenia. Participants were 51 female and 51 male outpatients comparable on demographic, clinical, and cognitive variables. Memory tests included both verbal and visual measures. Both groups scored below the normative mean of the memory and processing speed tests, except that females performed slightly above the mean on face recognition. Females outperformed males on verbal memory, visual recognition, and processing speed. Mediation regression analyses showed processing speed mediated immediate and delayed recall for both verbal and visual memory measures. Thus processing speed appears to be a critical variable for understanding cognitive deficits in schizophrenia and may be an important target for cognitive rehabilitation.     

Processing speed mediates gender differences in memory in schizophrenia

The primary aim of this study was to examine whether processing speed mediates the association between gender and episodic memory in schizophrenia. Participants were 51 female and 51 male outpatients comparable on demographic, clinical, and cognitive variables. Memory tests included both verbal and visual measures. Both groups scored below the normative mean of the memory and processing speed tests, except that females performed slightly above the mean on face recognition. Females outperformed males on verbal memory, visual recognition, and processing speed. Mediation regression analyses showed processing speed mediated immediate and delayed recall for both verbal and visual memory measures. Thus processing speed appears to be a critical variable for understanding cognitive deficits in schizophrenia and may be an important target for cognitive rehabilitation.     

Cognitive rehabilitation of the updating sub-component of working memory in schizophrenia: a case study

Working memory problems have been identified as a core cognitive deficit in schizophrenia. In this paper, we present the results of a cognitive rehabilitation programme (Duval & Coyette, 2005) administered to a schizophrenia patient, and specifically designed to improve the updating sub-component of working memory. The original feature of this programme was that it involved two types of updating exercises: cognitive and ecological. The purpose was to enable the patient to acquire cognitive strategies that alleviate the mental load of the central executive and to transfer them to daily life. The specificity and efficacy of the programme were assessed with multiple (cognitive, ecological and non-target) baseline measurements. In addition, several questionnaires were administered to assess the effect of the programme on subjective cognitive complaints affecting daily life, psychiatric symptoms and self-esteem. The results demonstrated the efficacy of the rehabilitation programme on the updating function and the generalisation of these beneficial effects to daily life. A significant decrease in both subjective cognitive complaints and psychiatric symptoms was also observed. However, the patient's self-esteem did not improve.     

Cognitive complaints in women with fibromyalgia: Are they due to depression or to objective cognitive dysfunction?

Introduction: Cognitive complaints are common in fibromyalgia, but it is unclear whether they represent an objective cognitive dysfunction or whether they could be explained by depressive symptoms. Here, we aim to elucidate the frequency of subjective cognitive complaints in a sample of women with fibromyalgia, in addition to analyzing associations between these subjective complaints and objective measures linked to the attention and executive cognitive domains. Finally, we aim to investigate the ability of demographic, clinical, and psychological variables to explain the subjective complaints observed. Method: One hundred and five women aged 30–55 years diagnosed with fibromyalgia completed a neuropsychological assessment, which included measures of attention and executive functions. They also completed self-report inventories of subjective cognitive complaints, depression, anxiety, intensity of pain, sleep quality, everyday physical functioning, and quality of life. Results: Eighty-four percent of the patients reported subjective cognitive complaints. Depression scores, everyday physical functioning, and working memory performance were most strongly associated with subjective cognitive complaints. These three variables were significant predictors for subjective cognitive complaints with a final model explaining 32% of the variance. Conclusions: Cognitive complaints are very frequent in patients with fibromyalgia, and these are related to functional and cognitive impairment as well as to depressive symptoms.     

Memory complaints and APOE-epsilon4 accelerate cognitive decline in cognitively normal elderly.

OBJECTIVE: To investigate to what extent subjective memory complaints and APOE-epsilon4 allele carriage predict future cognitive decline in cognitively intact elderly persons, by evaluating both their separate and combined effects. METHODS: We selected 1,168 subjects from the population-based Longitudinal Aging Study Amsterdam who were 62 to 85 years of age and had no obvious cognitive impairment at baseline (Mini-Mental State Examination [MMSE] score, > or =27). Memory complaints and APOE phenotypes were assessed at baseline. MMSE, the Auditory Verbal Learning Test (memory: immediate recall and delayed recall), and the Alphabet Coding Task-15 (information processing speed) were used to study cognitive decline. Follow-up data were collected after 3 and 6 years. Data were analyzed with generalized estimating equations, adjusted for age, sex, education, and depression. RESULTS: Baseline memory complaints were reported by 25.5% of the cognitively intact elderly persons. Overall, 25.3% of the subjects were carriers of at least one APOE-epsilon4 allele. Memory complaints were associated with a greater rate of decline in all cognitive measures, except immediate recall. In addition, APOE-epsilon4 allele carriers had a greater rate of cognitive decline shown by MMSE scores and slower information processing speeds after 6 years. The effects of both memory complaints and APOE-epsilon4 allele carriage were additive: subjects with both factors had a two times higher cognitive decline than did subjects without both factors. CONCLUSIONS: Both memory complaints and APOE-epsilon4 allele carriage predict cognitive decline at an early stage. This finding highlights the importance of subjective memory complaints, which are important even at an early stage when objective tests are still unable to detect cognitive deficits and are especially important for elderly carriers of the APOE-epsilon4 allele because they have an additional risk.     

Theory of mind performance in schizophrenia: diagnostic, symptom, and neuropsychological correlates

The purpose of this study was to explore the relationship between Theory of Mind (ToM) performance and schizophrenia subtype, symptom, and neuropsychological variables. One hundred twenty-eight stable outpatients with schizophrenia or schizoaffective disorder were assessed during the intake phase of a vocational and cognitive rehabilitation study. Results indicate that ToM performance differed significantly by schizophrenia diagnosis, with people diagnosed with disorganized schizophrenia performing the most poorly. Theory of Mind performance was also significantly correlated with measures of thought disorder and verbal memory. Regression analysis revealed that thought disorder and verbal memory measures explained 30% of the variance in ToM scores. Findings suggest that there is theory of mind variance in the schizophrenia population and theory of mind is strongly related to thought disorder, verbal memory, and cognitive disorganization. Contrary to previous reports, ToM was not related to measures of paranoia.     

Subjective memory complaints in an elderly population with poor sleep quality

Objectives: The association between sleep disturbances and cognitive decline in the elderly has been putative and controversial. We evaluated the relation between subjective sleep quality and cognitive function in the Korean elderly.

Method: Among 459 community-dwelling subjects, 352 subjects without depression or neurologic disorders (mean age 68.2?±?6.1) were analyzed in this study. All the participants completed the Korean version of the consortium to establish a registry for Alzheimer's disease neuropsychological battery (CERAD-KN) as an objective cognitive measure and subjective memory complaints questionnaire (SMCQ). Based on the Pittsburgh sleep quality index, two types of sleepers were defined: ‘good sleepers’ and ‘poor sleepers’.

Results: There were 192 good sleepers (92 men) and 160 poor sleepers (51 men). Poor sleepers reported more depressive symptoms and more use of sleep medication, and showed higher SMCQ scores than good sleepers, but there was no difference in any assessments of CERAD-KN. In the regression analysis, depressive symptoms and subjective sleep quality were associated with subjective memory complaints (β = 0.312, p < 0.001; β = 0.163, p = 0.005).

Conclusion: In the elderly without depression, poor sleep quality was associated with subjective memory complaints, but not with objective cognitive measures. As subjective memory complaints might develop into cognitive disorders, poor sleep quality in the elderly needs to be adequately controlled.     

Participation in the Chronic Phase of Stroke

Abstract

Background: Participation is a multidimensional concept, consisting of an objective and a subjective dimension. Many studies have focused on determinants of only 1 dimension of participation post stroke. Objective: To describe participation (both objective and subjective) and to determine how physical and cognitive independence and subjective complaints (pain, fatigue, and mood) influence participation in community-dwelling stroke survivors in the Netherlands. Methods: The Utrecht Scale for Evaluation of Rehabilitation (USER) measures physical and cognitive independence and subjective complaints. USER-Participation measures 3 dimensions of participation: frequency (objective perspective), restrictions (subjective perspective), and satisfaction (subjective perspective). Spearman correlations and backward linear regression analyses were used to analyze associations between the 3 USER-Participation scores with demographics, stroke characteristics, physical and cognitive independence, and subjective complaints. Results: Of the 111 participants, 48.5% returned to work post stroke, but mostly for only 1 to 16 hours a week. Experienced participation restrictions were most prevalent in physical exercise, chores in/around the house, housekeeping, and outdoor activities. On average, participants were relatively satisfied with their participation, but dissatisfaction occurred in cognition, activities outdoors, and work/housekeeping. Regression analysis revealed that objective participation was determined by physical and cognitive independence, age, and education, whereas subjective participation was determined by physical and cognitive independence, fatigue, and mood. Conclusions: Most participants experienced participation problems, despite relatively good physical recovery. In addition to physical and cognitive factors, subjective complaints of persons with stroke should be addressed in the rehabilitation program.     

Visual information processing deficits as biomarkers of vulnerability to schizophrenia: An event-related potential study in schizotypy

We aimed to clarify the importance of early visual processing deficits for the formation of cognitive deficits in the schizophrenia spectrum. We carried out an event-related potential (ERP) study using a computerised delayed matching to sample working memory (WM) task on a sample of volunteers with high and low scores on the Schizotypal Personality Questionnaire (SPQ). The amplitudes of the visual ERPs to the encoding and retrieval stimuli in the task were measured using the BESA software. The hypothesis was that the high schizotypes would have deficits in early visual processing (reduced P1 amplitude) and working memory similar to those observed in schizophrenia. The high schizotypy group identified fewer previously encoded target cues than the low schizotypy group in the WM task and their mean cue-evoked P1 amplitudes were significantly reduced, both in the encoding and the retrieval phases of the task. Accuracy on the WM task correlated with the P1 amplitude. None of the later components (N1 and P2) were significantly different between the groups, nor were there differences in performance on the CANTAB tests. The results are compatible with the hypothesis that trait vulnerability to schizophrenia is associated with impaired early visual processing which may contribute to impaired cognitive memory performance. However, the high schizotypes are apparently able to compensate for the visual processing deficits and perform normally when stimuli are presented for longer as in the CANTAB tasks. This study adds to growing evidence that the schizophrenia spectrum is characterized by early sensory abnormalities.     

Community dysfunction in schizophrenia: rate-limiting factors

The purpose of the present study was to investigate the impact of cognitive functioning, psychopathology, and severity of extrapyramidal side effects on community outcome in a group of Greek outpatients with schizophrenia. Participants were 40 outpatients with schizophrenia (25 men). Social adjustment was assessed with the Quality of Life Scale (QLS). Severity of symptoms of schizophrenia was measured with the Positive and Negative Syndrome Scale (PANNS), and extrapyramidal symptoms with the Extrapyramidal Symptom Rating Scale (ESRS). Finally, a battery of neuropsychological tests was administered in order to assess the following cognitive domains: executive functioning/set shifting, executive functioning/inhibition, fluency, verbal memory, visual memory, working memory, attention, visuospatial ability, and psychomotor speed/visual scanning. Total scores on the QLS were significantly correlated with negative symptoms, parkinsonism, and performance on the fluency tasks. Interpersonal relations subscale was significantly related with negative symptoms and fluency. No significant relationship was found between the Instrumental Role Functioning subscale and the PANSS, ESRS, or any cognitive domain. Scores on the Intrapsychic Foundation subscale were significantly correlated with negative symptoms and fluency. Finally, scores on the Common Objects and Activities subscale were significantly related with severity of negative symptoms, parkinsonism and visual memory. Our findings suggest that severity of negative symptoms, cognitive dysfunction, especially performance on fluency tasks and visual memory, as well as parkinsonism, are important determinants of functional outcome in schizophrenia.     

A longitudinal analysis of memory in patients with schizophrenia

Memory deficits are widely reported in patients with schizophrenia, but uncertainties remain about the extent and the longitudinal course of these deficits. Twenty-eight patients with a DSM-IV diagnosis of schizophrenia were tested on multiple aspects of memory at baseline, 9- and 18-month follow-up. Measures included: digit span, the Rivermead Behavioural Memory test (RBMT) battery, the Graded Naming Test (GNT) and several computerized memory tests from the Cambridge Automated Neuropsychological Testing Battery (CANTAB). A group of healthy controls (N=17) was tested on the CANTAB battery at baseline and 9-month follow up. The patients performed significantly poorer than controls on all CANTAB measures; however, there was no difference in change between groups over a 9-month period. Within-group patient comparisons revealed that symptoms reduced significantly over the study period, but had no association with memory. Significant improvements were observed for patients on two verbal memory tasks: the GNT and digit span, but not on any other measure. Interestingly, these were the only two tests on which patients were within normal limits at baseline. This study shows that patients with schizophrenia have deficits in multiple aspects of memory which remain stable over long periods of time. In addition, patients showed a tendency to improve on memory tasks which contained a verbal component.     

Preserved awareness of their cognitive deficits in patients with schizophrenia: convergent validity of the SSTICS

This study aimed to examine the convergent validity of the SSTICS. The association between the SSTICS and the five-factor model of the PANSS was also examined. One hundred and seventy-six schizophrenia-spectrum disorder patients were recruited. A correlation analysis was performed. The SSTICS score correlated with the score on the FPSES. The SSTICS score also correlated with the cognition factor of the PANSS. Our results demonstrate that the SSTICS is a good instrument for evaluating the subjective complaints of patients with schizophrenia. They also reveal good concordance between cognitive impairments experienced by patients and cognitive disorders assessed by a clinical rater.