Disorganization of semantic memory underlies alogia in schizophrenia: an analysis of verbal fluency performance in Japanese subjects

Unveiling altered connectivity between cognitive networks and cerebellum in schizophrenia

Cognitive functioning is a crucial aspect in schizophrenia (SZ), and when altered it has devastating effects on patients' quality of life and treatment outcomes. Several studies suggested that they could result from altered communication between the cortex and cerebellum. However, the neural correlates underlying these impairments have not been identified. In this study, we investigated resting state functional connectivity (rsFC) in SZ patients, by considering the interactions between cortical networks supporting cognition and cerebellum. In addition, we investigated the relationship between SZ patients' rsFC and their symptoms. We used fMRI data from 74 SZ patients and 74 matched healthy controls (HC) downloaded from the publicly available database SchizConnect. We implemented a seed-based connectivity approach to identify altered functional connections between specific cortical networks and cerebellum. We considered ten commonly studied resting state networks, whose functioning encompasses specific cognitive functions, and the cerebellum, whose involvement in supporting cognition has been recently identified. We then explored the relationship between altered rsFC values and Positive and Negative Syndrome Scale (PANSS) scores. The SZ group showed increased connectivity values compared with HC group for cortical networks involved in attentive processes, which were also linked to PANSS items describing attention and language-related processing. We also showed decreased connectivity between cerebellar regions, and increased connectivity between them and attentive networks, suggesting the contribution of cerebellum to attentive and affective deficits. In conclusion, our findings highlighted the link between negative symptoms in SZ and altered connectivity within the cerebellum and between the same and cortical networks supporting cognition.

Preliminary normative data for 12 categories using semantic verbal fluency: The role of animacy

Verbal fluency tasks are a common part of neuropsychological batteries and are frequently used in clinical and research practices to support the diagnosis of neurological impairments. Semantic verbal fluency is most frequently examined using only the category of animals. Little is known about the differences other semantic categories may present on semantic verbal fluency performance. The purpose of this study was to establish preliminary categorical normative data across twelve categories comprising of different animate and inanimate categories using semantic verbal fluency in neurotypical Lebanese-speaking adults and to determine the impact of category affiliation (animacy) on semantic verbal fluency performance. The task was administered to seventy female and male adults aged between 19 and 79 years having different educational levels. Participants generated the greatest number of exemplars for the category of body parts. Participants then produced exemplars in the following decreasing order: animals, vegetables, fruits, clothes, kitchen utensils, naturals, electronics, furniture, means of transportation, tools, and accessories. The animate categories were associated with the greatest number of exemplars compared to the inanimate. Clustering strategy might have been reinforced by the shared properties of animates.

Decrease in cognitive performance and increase of the neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios with higher doses of antipsychotics in women with schizophrenia: a cross-sectional study

BACKGROUND

We explored the relationship between symptoms, cognitive performance, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) (three markers of inflammation), and antipsychotic dose (in chlorpromazine units) in male and female patients with schizophrenia.

METHODS

We conducted a cross-sectional analysis in patients with schizophrenia of the complete blood count and the results of neuropsychological testing, using the Welch t-test to compare groups and the Pearson test for correlations.

RESULTS

We found that the NLR and the PLR are higher among women with schizophrenia when compared with men. In women, the NLR and the PLR correlate positively with antipsychotic drug dose and inversely with a working memory test (Direct Digit Span). Higher doses of antipsychotics are associated with worse working and semantic memory and mental flexibility in the women in our sample.

CONCLUSION

Higher doses of antipsychotics were associated with worse working and semantic memory and mental flexibility in women with schizophrenia. No such correlations were present in men, suggesting that, in female patients, cognitive performance deteriorates as the antipsychotic dose is increased, a finding that could be mediated by inflammatory mechanisms, given the demonstrated relationship to biomarkers of inflammation - e.g., the NLR and the PLR.

TRIAL REGISTRATION

NCT03788759 (ClinicalTrials.gov).

Linguistic anomalies observed in the Sentence Completion Test in patients with schizophrenia

BACKGROUND

Schizophrenia is a chronic, debilitating disorder characterised by distorted thinking, perceptions, behaviours, and even language impairments. We investigated the linguistic anomalies in Korean schizophrenia patients compared to non-psychotic psychiatric controls to determine whether the linguistic anomalies in English speakers with schizophrenia were replicated in Korean speakers.

METHODS

Thirty-four schizophrenia patients and 70 non-psychotic psychiatric controls were included in this study. The SCT was utilised as the text data for analysis. For linguistic analysis, we evaluated texts regarding semantics and syntax. We separately counted the number of semantic or syntactic errors in the written texts of study participants and compared them between patients and controls.

RESULTS

Schizophrenia patients showed significantly more semantic errors (p < .001) and syntactic errors (p < .001) per 1,000 characters than non-psychotic psychiatric controls. Specifically, inappropriate word or syntactic component selection is noticeable in schizophrenia patients. These differences were still significant after adjusting for general intelligence measured by the K-WAIS-IV.

CONCLUSION

Schizophrenia patients showed both semantic and syntactic errors in written language. Moreover, these errors seemed to be partly independent of general intelligence. Notably, patients showed a noticeable number of syntactic errors. Further investigation into the language of patients with schizophrenia and schizophrenia-spectrum disorders is required.

Formal thought disorder in patients with first-episode schizophrenia: Results of a one-year follow-up study

Formal thought disorder (FTD) refers to abnormal speech patterns that can be characterized by deficiencies in thought organization and direction. The present study aimed to assess the factor structure of FTD and to examine its relationship with cognition and clinical features at first admission in patients with first-episode schizophrenia. We also examined the course of FTD during the twelve months after first admission. We assessed FTD using the alogia items of the Scale for the Assessment of Negative Symptoms and FTD items of the Scale for the Assessment of Positive Symptoms in 160 drug-naïve patients. A three-factor structure as a disorganization factor, poverty factor, and verbosity factor were found in principal component analysis. The poverty factor was correlated negatively with executive functions, attention, and global cognition. The poverty factor was also correlated with global functioning. Admission FTD factor scores were not related to global functioning and work/study status at one year. The positive-FTD score decreased from admission to the third month, but no change occurred from the third to the twelfth month. The negative-FTD score did not differ throughout the follow-up. Our findings showed that FTD had three factors. Each factor had a different relationship with cognition and functioning.

Facilitative Effects of Transcranial Direct Current Stimulation on Semantic Memory Examined by Text-Mining Analysis in Patients With Schizophrenia

Background: Beneficial effects of transcranial direct current stimulation (tDCS) are relevant to cognition and functional capacity, in addition to psychiatric symptoms in patients with schizophrenia. However, whether tDCS would improve higher-order cognition, e.g., semantic memory organization, has remained unclear. Recently, text-mining analyses have been shown to reveal semantic memory. The purpose of the current study was to determine whether tDCS would improve semantic memory, as evaluated by text-mining analyses of category fluency data, in patients with schizophrenia. Methods: Twenty-eight patients entered the study. Cognitive assessment including the category fluency task was conducted at baseline (before tDCS treatment) and 1 month after t administration of tDCS (2 mA × 20 min, twice per day) for 5 days, according to our previous study. The category fluency data were also obtained from 335 healthy control subjects. The verbal outputs (i.e., animal names) from the category fluency task were submitted to singular valued decomposition (SVD) analysis. Semantic memory structures were estimated by calculating inter-item cosines (i.e., similarities) among animal names frequently produced in the category fluency task. Data were analyzed longitudinally and cross-sectionally to compare the semantic structure within the patient group (i.e., baseline vs. follow-up) and between groups (patients vs. healthy controls). In the former, semantic associations for frequent items were compared in the form of cosine profiles, while in the latter, the difference in the magnitude of the correlations for inter-item cosines between healthy controls and patients (baseline, follow-up) was examined. Results: Cosine profiles in the patient group became more cluster-based (i.e., pet, carnivores, and herbivores) at follow-up compared to those at baseline, yielding higher cosines within subcategories. The correlational coefficient of inter-item cosines between healthy controls and patients was significantly greater at follow-up compared to baseline; semantic associations in patients approached the normality status after multi-session tDCS. Conclusions: To our knowledge, this is the first study to demonstrate the facilitative effect of tDCS on semantic memory organization in patients with schizophrenia. Text-mining analysis was indicated to effectively evaluate semantic memory structures in patients with psychiatric disorders.

fNIRS Evaluation of Frontal and Temporal Cortex Activation by Verbal Fluency Task and High-Level Cognition Task for Detecting Anxiety and Depression

Anxiety and depression are widespread psychosis which are believed to affect cerebral metabolism, especially in frontal and temporal cortex. The comorbidity patients of anxiety and depression (A&D) have more serious clinical symptoms. Functional near-infrared spectroscopy (fNIRS) is a noninvasive modality used to monitor human brain oxygenation, and it could be considered as a potential tool to detect psychosis which may lead to abnormal cerebral oxygen status when the brain is activated. However, how sensitive the cerebral oxygenation response to the cortex activation and whether these responses are consistent at different stages of A&D or different regions still remains unclear. In this study, a conventional physiological paradigm for cortex activation, i.e., verbal fluency task (VFT), and a relatively new paradigm, i.e., high-level cognition task (HCT), were compared to detect A&D through a longitudinal measurement of cerebral oxygen status by fNIRS. The A&D patients at the acute, consolidation and maintenance stages as well as the healthy subjects participated in the VFT and HCT paradigms, respectively. For the VTF paradigm, the subject was instructed to answer questions of phrase constructions within 60 s. For the HCT paradigm, the subject was instructed to categorize items, logical reasoning, and comprehensive judgment and write down the answers within 60 s. For most of the subjects, the oxy-Hb is found to increase remarkably, accompanied with a relatively small reduction in deoxy-Hb when subject to both paradigms. The statistical analyses show a relatively large variability within any group, leading to the significant difference that was only found between A&D at the acute stage and healthy subjects in the temporal lobe region (p < 0.001). Nevertheless, HCT would activate more oxygen increment when compared with the VFT, with a large integral value in oxy-Hb. On average, the oxy-Hb integral value of the A&D patients differs substantially at different stages when subject to HCT paradigm. Moreover, the prefrontal lobe and temporal lobe responses were more consistent to the HCT paradigm rather than the VFT paradigm. Under the VFT paradigm, however, no remarkable difference in integral value was found among the three stages, either at the prefrontal lobe or at the temporal lobe. This study indicated that HCT, which is intensively involved in brain function, would activate more oxygenation changes in the cerebral cortex. Additionally, with good performance at distinguishing different stages according to the oxy-Hb criterion, the HCT has the potential to evaluate the therapeutic effects for A&D patients.

A cognitive model of diminished expression in schizophrenia: The interface of metacognition, cognitive symptoms and language disturbances

The resistance of negative symptoms to pharmacologic treatment has spurred interest in understanding the psychological factors that contribute to their formation and persistence. However, little is understood about the psychological processes that reinforce and sustain the negative symptoms domain of diminished expression. Prior research has shown that higher levels of diminished expression relate to deficits in metacognitive capacity. We propose a more complex model in which diminished expression occurs when impairments in metacognitive self-reflectivity, alterations in higher-order language structure, and cognitive symptoms interact and thus interfere with persons' ability to understand and express emotions in ways others can recognize. Individuals with schizophrenia-spectrum disorders (N = 201) provided personal narratives detailing their life story and reflections about their mental illness. Self-reflectivity was measured with the Metacognition Assessment Scale-Abbreviated, and situation models were extracted from participants' personal narratives via Coh-Metrix 3.0, an automated program that calculates language indices. Diminished expression and cognitive symptoms were measured with the Positive and Negative Syndrome Scale. Structural equation models (SEM) examined whether self-reflectivity mediated the impact of cognitive symptoms and situation models on diminished expression. Results of the SEM revealed that self-reflectivity partially mediated the impact of situation models on diminished expression (β = -.073, p = .008, ±95% CI [-0.126, -0.019]). and fully mediated the influence of cognitive symptoms in diminished expression (β = 0.099, p = .001, ±95% CI [0.038, 0.160]). In conclusion, results suggest that self-reflectivity, linguistic cohesion, and cognitive symptoms may be useful targets for intervention in efforts to treat diminished expression in psychosis.

Metacognition Is Uniquely Related to Concurrent and Prospective Assessments of Negative Symptoms Independent of Verbal Memory in Serious Mental Illness

The inability to synthesize information into experience of self and others could be one significant cause of negative symptoms. To explore this possibility, we examined the relationships between baseline metacognition and concurrent and prospective negative symptoms controlling for verbal memory. The participants were 62 adults diagnosed with serious mental illness enrolled in outpatient treatment. Metacognition was measured with the Metacognitive Assessment Scale-Abbreviated, symptoms were assessed using the Brief Psychiatric Rating Scale, and verbal memory was assessed using the California Verbal Learning Test. Significant correlations were found, indicating that poorer overall metacognition was associated with greater levels of negative symptoms assessed concurrently (r = 0.39) and 1 month later (r = 0.36). A significant relationship persisted after controlling for verbal memory and education. These findings support the idea that metacognitive deficits are related to negative symptoms and point to the potential of metacognitive interventions to positively influence negative symptoms.

Semantic Memory Impairment Across the Schizophrenia Continuum: A Meta-Analysis of Category Fluency Performance

Semantic memory (SM) impairments are a core feature of schizophrenia and are present along the psychosis continuum. It is, however, unclear whether the degree of SM impairments vary along this continuum and if demographic and clinical factors affect impairment severity. This study performed meta-analyses of category fluency task performance (a task commonly used to assess SM) in 4 groups along the schizophrenia continuum: high schizotypes (HSZT), first-degree relatives (FDR), recent-onset patients (≤2 y; ROP) and chronic patients (CSZ). Electronic databases were searched for relevant studies published up to October 2019 resulting in the inclusion of 48 articles. The main analyses assessed fluency productivity scores in 2978 schizophrenia spectrum disorder patients, 340 first-degree relatives of schizophrenia spectrum disorder patients, and 3204 healthy controls. Further analyses assessed errors, mean cluster size, and switching data that were available in the CSZ group only. Results revealed significant impairments in fluency productivity were present in the FDR, ROP, and CSZ groups relative to healthy controls, but not in HSZT. In the CSZ group, significant differences relative to healthy controls were also observed in non-perseverative errors, mean cluster size, and number of switches. The findings collectively suggest that SM deficits are present at each stage of the continuum and are exacerbated post-illness onset. They also support the centrality of SM impairments in schizophrenia and most elevated risk groups. Future studies with more diverse measures of SM function are needed to replicate and extend this research.

Language in schizophrenia and aphasia: the relationship with non-verbal cognition and thought disorder

Objective: To determine the relationship between language abnormalities and broader cognitive impairment and thought disorder by examining language and cognition in schizophrenia and aphasia (a primary language disorder).Methods: Cognitive and linguistic profiles were measured with a battery of standardised tests, and compared in a clinical population of n = 50 (n = 30 with schizophrenia and n = 20 with aphasia) and n = 61 non-clinical comparisons (n = 45 healthy controls and n = 16 non-affected first-degree relatives of patients with schizophrenia).Results: Both clinical groups showed linguistic deficits. Verbal impairment was more severe in participants with aphasia, whereas non-verbal performance was more affected in participants with schizophrenia. In schizophrenia, but not in aphasia, verbal and non-verbal performance were associated. Formal thought disorder was associated with impairment in executive function and in grammatical, but not naming, tasks.Conclusion: While patients with schizophrenia and aphasia showed language impairments, the nature and cognitive basis of these impairments may be different; language performance disassociates from broader cognitive functioning in aphasia but may be an intrinsic expression of a broader cognitive impairment in schizophrenia. Thought disorder may represent a core malfunction of grammatical processing. Results suggests that communicative ability may be a valid target in cognitive remediation strategies in schizophrenia.

Neurocognitive and linguistic correlates of positive and negative formal thought disorder: A meta-analysis

Executive dysfunction and language impairment are the most prominent neuropsychological models of formal thought disorder (FTD) in schizophrenia. However, available studies have provided contradictory findings regarding the accuracy of these models. Furthermore, specific neurocognitive underpinnings of positive FTD (PosFTD) and negative FTD (NegFTD) are not clear. Following the systematic review of schizophrenia studies, a random-effects meta-analysis of the relationship between FTD and neurocognition/language in schizophrenia was conducted in 52 reports including 2805 patients. Neurocognition was significantly associated with both PosFTD (r = -0.21, CI = -0.14 to -0.27) and NegFTD (r = -0.24, CI = -0.18 to -0.30). Both PosFTD (r = ranged from -0.18 to -0.27) and NegFTD (r = ranged from -0.19 to -0.23) were significantly correlated with verbal memory, visual memory, attention, and processing speed. In meta-analyses of executive functions, PosFTD was significantly associated with working memory (r = -0.21), planning (r = -0.19), and inhibition (r = -0.21) and NegFTD was significantly associated with planning (r = -0.27), fluency (r = -0.27), and working memory (r = -0.24). In meta-analyses of linguistic variables, PosFTD was associated with deficits in syntactic comprehension (r = -0.27) and semantic processing (r = -0.18). In contrast, NegFTD was associated only with semantic comprehension (r = -0.21). Both PosFTD and NegFTD were significantly associated with executive dysfunction, neurocognitive deficits and semantic dysfunction but syntactic deficits were more specific to PosFTD. There were also some distinct patterns of relationships between the pattern of executive dysfunction and types of FTD. Fluency deficit was associated more strongly with NegFTD and poor inhibition was more specifically related to PosFTD. Current findings suggest that neurocognitive and linguistic correlates of PosFTD and NegFTD might be partly different.

Neurocognitive functioning and quality of life in patients with and without deficit syndrome of schizophrenia

Deficit syndrome of schizophrenia is a subtype of schizophrenia characterized by primary and enduring negative symptoms. This study examined the differences in neurocognitive functioning and quality of life (QOL) between deficit and non-deficit patients, and specific predictors of both clinical measures. Overall, 344 subjects (175 patients with non-deficit schizophrenia (NDSZ), 58 patients with deficit schizophrenia (DSZ) and 111 healthy controls) were evaluated on severity of psychopathology, QOL and a smaller subset of 198 subjects (104 NDSZ, 27 DSZ, 67 healthy controls) underwent neurocognitive assessments. Multivariate analyses were used to determine differences in outcomes between subject groups and predictors of clinical measures. Both DSZ and NDSZ had significantly worse QOL compared with healthy controls. DSZ had more extensive cognitive deficits compared with healthy controls and performed worse on semantic fluency task compared to NDSZ. Multiple linear regression analysis found that DSZ, shorter duration of illness were associated with poorer QOL whereas fewer years of education, lower premorbid intelligence were associated with poorer overall neurocognitive functioning. The poorer QOL, greater extent of neurocognitive deficits especially semantic fluency associated with DSZ behoves the need for greater attention during clinical evaluation and treatment planning of this subgroup of individuals with schizophrenia.

Predictors of negative symptoms in the chronic phase of schizophrenia: A cross-sectional study

This study was designed to investigate the relationship between negative symptoms and key indicators for long-term hospital stays among inpatients with schizophrenia. A further aim was to elucidate the clinical determinants of negative symptoms. The following were used as index factors: age, duration of illness, duration of hospitalization, age at onset, years of education, smoking status, body mass index, concentrations of serum triglycerides, total cholesterol, uric acid, QTc interval duration from electrocardiography, dose equivalents of antipsychotic and anticholinergic agents, neurocognitive function, drug-induced extrapyramidal symptoms, involuntary movements, and psychiatric symptoms. Spearman's rank correlation coefficients were calculated and regression analyses were performed to examine associations between these factors and negative symptoms. Positive symptoms correlated positively with negative symptoms as rated on the Brief Psychiatric Rating Scale. Age at onset correlated negatively with negative symptoms. Multiple regression analysis showed that dose equivalents of atypical antipsychotics and positive symptoms predicted negative symptoms. Increasing our understanding of these predictors as key indicators of the severity of negative symptoms may aid in the reconsideration of therapeutic programs for chronic schizophrenia.

Semantic Memory Organization in Japanese Patients With Schizophrenia Examined With Category Fluency

BACKGROUND

Disorganization of semantic memory in patients with schizophrenia has been studied by referring to their category fluency performance. Recently, data-mining techniques such as singular value decomposition (SVD) analysis have been reported to be effective in elucidating the latent semantic memory structure in patients with schizophrenia. The aim of this study is to investigate semantic memory organization in patients with schizophrenia using a novel method based on data-mining approach.

METHOD

Category fluency data were collected from 181 patients with schizophrenia and 335 healthy controls at the Department of Psychiatry, Osaka University. The 20 most frequently reported animals were chosen for SVD analysis. In the two-dimensional (2D) solution, item vectors (i.e., animal names) were plotted in the 2D space of each group. In the six-dimensional (6D) solution, inter-item similarities (i.e., cosines) were calculated among items. Cosine charts were also created for the six most frequent items to show the similarities to other animal items.

RESULTS

In the 2D spatial representation, the six most frequent items were grouped in the same clusters (i.e., dog, cat as pet cluster, lion, tiger as wild/carnivorous cluster, and elephant, giraffe as wild/herbivorous cluster) for patients and healthy adults. As for 6D spatial cosines, the correlations (Pearson's r) between 17 items commonly generated in the two groups were moderately high. However, cosine charts created for the three pairs from the six most frequent animals (dog-cat, lion-tiger, elephant-giraffe) showed that pair-wise similarities between other animals were less salient in patients with schizophrenia.

DISCUSSION

Semantic memory organization in patients with schizophrenia, revealed by SVD analysis, did not appear to be seriously impaired in the 2D space representation, maintaining a clustering structure similar to that in healthy controls for common animals. However, the coherence of those animals was less salient in 6D space, lacking pair-wise similarities to other members of the animal category. These results suggests subtle but structural differences between the two groups. A data-mining approach by means of SVD analysis seems to be effective in evaluating semantic memory in patients with schizophrenia, providing both a visual representation and an objective measure of the structural alterations.

Individual negative symptoms and domains - Relevance for assessment, pathomechanisms and treatment

The negative symptoms of schizophrenia can be divided into two domains. Avolition/apathy includes the individual symptoms of avolition, asociality and anhedonia. Diminished expression includes blunted affect and alogia. Until now, causes and treatment of negative symptoms have remained a major challenge, which is partially related to the focus on negative symptoms as a broad entity. Here, we propose that negative symptoms may become more tractable when the different domains and individual symptoms are taken into account. There is now increasing evidence that the relationship with clinical variables - in particular outcome - differs between the domains of avolition/apathy and diminished expression. Regarding models of negative symptom formation, those relevant to avolition/apathy are now converging on processes underlying goal-directed behavior and dysfunctions of the reward system. In contrast, models of the diminished expression domains are only beginning to emerge. The aim of this article is to review the specific clinical, behavioral and neural correlates of individual symptoms and domains as a better understanding of these areas may facilitate specific treatment approaches.

The current conceptualization of negative symptoms in schizophrenia

Negative symptoms have long been conceptualized as a core aspect of schizophrenia. They play a key role in the functional outcome of the disorder, and their management represents a significant unmet need. Improvements in definition, characterization, assessment instruments and experimental models are needed in order to foster research aimed at developing effective interventions. A consensus has recently been reached on the following aspects: a) five constructs should be considered as negative symptoms, i.e. blunted affect, alogia, anhedonia, asociality and avolition; b) for each construct, symptoms due to identifiable factors, such as medication effects, psychotic symptoms or depression, should be distinguished from those regarded as primary; c) the five constructs cluster in two factors, one including blunted affect and alogia and the other consisting of anhedonia, avolition and asociality. In this paper, for each construct, we report the current definition; highlight differences among the main assessment instruments; illustrate quantitative measures, if available, and their relationship with the evaluations based on rating scales; and describe correlates as well as experimental models. We conclude that: a) the assessment of the negative symptom dimension has recently improved, but even current expert consensus-based instruments diverge on several aspects; b) the use of objective measures might contribute to overcome uncertainties about the reliability of rating scales, but these measures require further investigation and validation; c) the boundaries with other illness components, in particular neurocognition and social cognition, are not well defined; and d) without further reducing the heterogeneity within the negative symptom dimension, attempts to develop successful interventions are likely to lead to great efforts paid back by small rewards.

The current conceptualization of negative symptoms in schizophrenia

Negative symptoms have long been conceptualized as a core aspect of schizophrenia. They play a key role in the functional outcome of the disorder, and their management represents a significant unmet need. Improvements in definition, characterization, assessment instruments and experimental models are needed in order to foster research aimed at developing effective interventions. A consensus has recently been reached on the following aspects: a) five constructs should be considered as negative symptoms, i.e. blunted affect, alogia, anhedonia, asociality and avolition; b) for each construct, symptoms due to identifiable factors, such as medication effects, psychotic symptoms or depression, should be distinguished from those regarded as primary; c) the five constructs cluster in two factors, one including blunted affect and alogia and the other consisting of anhedonia, avolition and asociality. In this paper, for each construct, we report the current definition; highlight differences among the main assessment instruments; illustrate quantitative measures, if available, and their relationship with the evaluations based on rating scales; and describe correlates as well as experimental models. We conclude that: a) the assessment of the negative symptom dimension has recently improved, but even current expert consensus-based instruments diverge on several aspects; b) the use of objective measures might contribute to overcome uncertainties about the reliability of rating scales, but these measures require further investigation and validation; c) the boundaries with other illness components, in particular neurocognition and social cognition, are not well defined; and d) without further reducing the heterogeneity within the negative symptom dimension, attempts to develop successful interventions are likely to lead to great efforts paid back by small rewards.

Verbal fluency, clustering, and switching in patients with psychosis following traumatic brain injury (PFTBI)

Verbal fluency in patients with psychosis following traumatic brain injury (PFTBI) has been reported as comparable to healthy participants. This finding is counterintuitive given the prominent fluency impairments demonstrated post-traumatic brain injury (TBI) and in psychotic disorders, e.g. schizophrenia. We investigated phonemic (executive) fluency (3 letters: 'F' 'A' and 'S'), and semantic fluency (1 category: fruits and/or vegetables) in four matched groups; PFTBI (N=10), TBI (N=10), schizophrenia (N=23), and healthy controls (N=23). Words produced (minus perseverations and errors), and clustering and switching scores were compared for the two fluency types across the groups. The results confirmed that PFTBI patients do show impaired fluency, aligned with existing evidence in TBI and schizophrenia. PFTBI patients produced the least amount of words on the phonemic fluency ('A') trial and total score, and demonstrated reduced switching on both phonemic and semantic tasks. No significant differences in clustering performance were found. Importantly, the pattern of results suggested that PFTBI patients share deficits with their brain-injured (primarily executive), and psychotic (executive and semantic), counterparts, and that these are exacerbated by their dual-diagnosis. These findings add to a very limited literature by providing novel evidence of the nature of fluency impairments in dually-diagnosed PFTBI.

Creativity and positive symptoms in schizophrenia revisited: Structural connectivity analysis with diffusion tensor imaging

Both creativity and schizotypy are suggested to be manifestations of the hyperactivation of unusual or remote concepts/words. However, the results of studies on creativity in schizophrenia are diverse, possibly due to the multifaceted aspects of creativity and difficulties of differentiating adaptive creativity from pathological schizotypy/positive symptoms. To date, there have been no detailed studies comprehensively investigating creativity, positive symptoms including delusions, and their neural bases in schizophrenia. In this study, we investigated 43 schizophrenia and 36 healthy participants using diffusion tensor imaging. We used idea, design, and verbal (semantic and phonological) fluency tests as creativity scores and Peters Delusions Inventory as delusion scores. Subsequently, we investigated group differences in every psychological score, correlations between fluency and delusions, and relationships between these scores and white matter integrity using tract-based spatial statistics (TBSS). In schizophrenia, idea and verbal fluency were significantly lower in general, and delusion score was higher than in healthy controls, whereas there were no group differences in design fluency. We also found positive correlation between phonological fluency and delusions in schizophrenia. By correlation analyses using TBSS, we found that the anterior part of corpus callosum was the substantially overlapped area, negatively correlated with both phonological fluency and delusion severity. Our results suggest that the anterior interhemispheric dysconnectivity might be associated with executive dysfunction, and disinhibited automatic spreading activation in the semantic network was manifested as uncontrollable phonological fluency or delusions. This dysconnectivity could be one possible neural basis that differentiates pathological positive symptoms from adaptive creativity.

Negative symptoms of schizophrenia: clinical features, relevance to real world functioning and specificity versus other CNS disorders

Negative symptoms have long been recognized as a central feature of the phenomenology of schizophrenia, dating back to the early descriptions by Kraepelin and Bleuler. Over the ensuing century, there have been important clarifications and reconceptualizations regarding the phenomenology of negative symptoms in schizophrenia. This review explores these developments, including the delineation of two underlying subdomains of negative symptoms - amotivation (i.e., avolition/apathy and asociality) and diminished expression (i.e., poverty of speech and affective flattening). Further, advances in our understanding of specific motivational and hedonic deficits seen in schizophrenia are explored. The findings that negative symptoms stand apart from depressive and cognitive symptoms in schizophrenia are also discussed. In terms of the predictors of functional outcomes in schizophrenia, we explore both the direct role of negative symptoms in this regard, as well as their indirect role through cognition. We then broaden our examination of negative symptoms to related disorders across the schizophrenia spectrum, as well as to other neuropsychiatric illnesses, where negative symptoms have been increasingly recognized. We explore the differential characteristics of negative symptoms across these illnesses, and their relevance to functional outcomes. This transdiagnostic presence and relevance of negative symptoms highlights the need for continued exploration of their phenomenology and neurobiology as we move to develop effective interventions to address these debilitating symptoms and improve functional outcomes.

Does sleep improve memory organization?

Sleep can integrate information into existing memory networks, look for common patterns and distil overarching rules, or simply stabilize and strengthen the memory exactly as it was learned. Recent research has shown that sleep facilitates abstraction of gist information as well as integration across multiple memories, insight into hidden solutions, and even the ability to make creative connections between distantly related ideas and concepts. To investigate the effect of sleep on memory organization, 35 normal volunteers were randomly assigned either to the sleep (n = 17) or wake group (n = 18). The sleep subjects performed the Japanese Verbal Learning Test (JVLT), a measure of learning and memory, three times in the evening, and slept. On the following morning (9 h later), they were asked to recall the words on the list. The wake subjects took the same test in the morning, and were asked to recall the words in the same time interval as in the sleep group. The semantic clustering ratio (SCR), divided by the total number of words recalled, was used as an index of memory organization. Our main interest was whether the sleep subjects elicit a greater increase in this measure from the third to the fourth assessments. Time × Group interaction effect on SCR was not significant between the sleep group and wake group as a whole. Meanwhile, the change in the SCR between the third and fourth trials was negatively correlated with duration of nocturnal waking in the sleep group, but not other sleep indices. Based on this observation, further analysis was conducted for subjects in the sleep group who awoke nocturnally for <60 min for comparison with the wake group. A significant Time × Group interaction was noted; these "good-sleepers" showed a significantly greater improvement in the memory index compared with the wake subjects. These results provide the first suggestion that sleep may enhance memory organization, which requires further study.

Splitting in schizophrenia and borderline personality disorder

Background

Splitting describes fragmentation of conscious experience that may occur in various psychiatric disorders. A purpose of this study is to examine relationships between psychological process of splitting and disturbed cognitive and affective functions in schizophrenia and borderline personality disorder (BPD).

Methods

In the clinical study, we have assessed 30 patients with schizophrenia and 35 patients with BPD. The symptoms of splitting were measured using self-reported Splitting Index (SI). As a measure of semantic memory disorganization we have used verbal fluency test. Other psychopathological symptoms were assessed using Health of the Nation Outcome Scale (HoNOS).

Results

Main results show that SI is significantly higher in BPD group than in schizophrenia, and on the other hand, verbal fluency is significantly lower in schizophrenia group. Psychopathological symptoms measured by HoNOS are significantly higher in the BPD group than in schizophrenia. Significant relationship was found between verbal fluency and the SI “factor of others” (Spearman r = −0.52, p<0.01) in schizophrenia patients.

Conclusions

Processes of splitting are different in schizophrenia and BPD. In BPD patients splitting results to mental instability, whereas in schizophrenia the mental fragmentation leads to splitting of associations observed as lower scores of verbal fluency, which in principle is in agreement with Bleuler’s historical concept of splitting in schizophrenia.

A positive correlation between serum levels of mature brain-derived neurotrophic factor and negative symptoms in schizophrenia

A meta-analysis study reported serum brain-derived neurotrophic factor (BDNF) levels as a potential biomarker for schizophrenia. However, at the time, commercially available human ELISA kits were unable to distinguish between pro-BDNF (precursor BDNF) and mature BDNF, because of limited antibody specificity. Here, we used new ELISA kits, to examine serum levels of mature BDNF and matrix metalloproteinase-9 (MMP-9), which converts pro-BDNF to mature BDNF in schizophrenia. Sixty-three patients with chronic schizophrenia and 52 age- and sex-matched healthy controls were enrolled. Patients were evaluated using the Brief Psychiatry Rating Scale, the Scale for the Assessment of Negative Symptoms (SANS) and neuropsychological tests. Neither serum mature BDNF nor MMP-9 levels differed between patients and controls. In male subgroups, serum MMP-9 levels of smoking patients were higher than those of non-smoking patients, but this was not observed in male controls or the female subgroup. In patients, serum mature BDNF levels were associated with SANS total scores and the Information subtest scores of the Wechsler Adult Intelligence Scale Revised (WAIS-R), while serum MMP-9 levels were associated with smoking and category fluency scores. These findings suggest that neither mature BDNF nor MMP-9 is a suitable biomarker for schizophrenia, although further studies using large samples are needed.

Possible dose-side effect relationship of antipsychotic drugs: relevance to cognitive function in schizophrenia

Management of adverse events is a major concern of clinicians who use antipsychotic drugs. The incidence of motor side effects is dose dependent. Atypical antipsychotic drugs are less likely to induce neurologic side effects compared with typical (conventional) antipsychotics, such as haloperidol. Some recent, large-scale studies have shown that the incidence of metabolic side effects often associated with atypical agents does not differ among typical and atypical antipsychotics. Cognitive function, such as verbal learning memory, working memory, executive function, verbal fluency and attention/information processing, is the most influential determinant of outcome in patients with schizophrenia. Atypical antipsychotic drugs have been shown to be more efficacious in treating cognitive disturbances of schizophrenia compared with typical antipsychotic drugs. Serotonin (5-hydroxytryptamine [5-HT]) receptor subtypes, such as the 5-HT1A receptor, are considered to mediate the ability of antipsychotic drugs to enhance cognition. On the other hand, treatment with some atypical agents, such as risperidone, may deteriorate working memory in some people with early-stage schizophrenia. The paradoxical side effects of these antipsychotic drugs in terms of cognition may be attributable to dose, duration of treatment and type of cognitive domain. Further research will add to the worldwide endeavor to develop more effective psychotropic drugs accompanied with minimal side effects, for the improvement of cognition, adherence and long-term outcome in patients with schizophrenia or other major psychiatric illnesses.

Building a neurocognitive profile of thought disorder in schizophrenia using a standardized test battery

A core symptom of schizophrenia is thought disorder (TD). The cognitive abilities of semantic processing and executive function are argued to be etiologically linked to TD. However, there has been no comprehensive investigation of neurocognition in TD to date. The neurocognitive profile of 58 schizophrenia patients and 48 healthy controls was examined using the MATRICS Consensus Cognitive Battery and the D-KEFS Color-Word Interference Test. TD patients performed more poorly than non-TD patients on the cognitive domains of Verbal Learning and Inhibition, reflective of semantic and executive function respectively, confirming their critical roles over and above other cognitive deficits in schizophrenia.

The relationship between positive and negative automatic thought and activity in the prefrontal and temporal cortices: a multi-channel near-infrared spectroscopy (NIRS) study

BACKGROUND

Recently, neurobiological studies of the cognitive model of depression have become vastly more important, and a growing number of such studies are being reported. However, the relationship between the proportion of positive and negative automatic thought and activity in the prefrontal and temporal cortices has not yet been explored. We examined the relationship between brain activity and the proportion of positive and negative automatic thought in patients with major depressive disorder (MDD), using multi-channel near-infrared spectroscopy (NIRS).

METHODS

We recruited 75 individuals with MDD (36 females; mean age=39.23 ± 12.49). They completed the Hamilton Rating Scale for Depression, Automatic Thoughts Questionnaire-Revised, Japanese version of the National Adult Reading Test, and the State-Trait Anxiety Inventory. Brain activation was measured by 52-channel NIRS.

RESULTS

We found that activation in the vicinity of the right superior temporal gyrus is related to a deviation to negative of the proportion of positive and negative thoughts in individuals with MDD. Left dorsolateral prefrontal cortex activity was higher in the group with comparatively frequent positive thought.

LIMITATIONS

Our participants were patients taking antidepressant medication, which is known to influence brain activity. Second, the poor spatial resolution of NIRS increases the difficulty of identifying the measurement position.

CONCLUSIONS

We found that activation of the prefrontal and temporal cortices is related to the proportion of automatic thoughts in the cognitive model of depression.

A discursive psychology critique of semantic verbal fluency assessment and its interpretation

Semantic verbal fluency (SVF), a psychological assessment method used in experimental research and clinical practice, requires participants to produce as many words as possible from a given superordinate category (e.g., “animals,” “vehicles”). Features of responses, such as the prototypicality and ordering of items, are then interpreted as if revealing details about the organisation—or, in instances of ostensibly atypical performance, disorganisation—of participants’ underlying conceptual and/or semantic systems. In this paper, we draw upon perspectives from Discursive Psychology, particularly the work of Derek Edwards (e.g., Edwards, 1997), to argue against this position. Following critical discussion of SVF’s strongly cognitivist theoretical foundations, we present analyses of social interactions across various contexts, including the real-life administration of the paradigm with a child with autism, to suggest that performance is unavoidably socially mediated rather than solely internally driven. Our arguments challenge SVF’s validity and its role in the description of “cognitive disorder.”

Predictors of quality of life in inpatients with schizophrenia

Shortening hospital stays has become a key focus in psychiatric care in recent years. However, patients with schizophrenia account for about 60% of inpatients in psychiatry departments in Japan. This study was designed to investigate the relationship between quality of life (QOL) and key indicators for long-term hospital stays among schizophrenia inpatients. A further aim was to elucidate the clinical determinants of QOL among long-stay inpatients. The study sample consisted of 217 inpatients with schizophrenia. Age, duration of illness, duration of hospitalization, years of education, body mass index, neurocognitive function, drug-induced extrapyramidal symptoms, involuntary movements, psychiatric symptoms, and dose equivalents of antipsychotics and anticholinergic agents were used as index factors. Pearson linear correlation and regression analyses were performed to examine the associations between QOL and the above-mentioned factors. Negative symptoms, psychological discomfort, and resistance as rated on the Brief Psychiatric Rating Scale (BPRS) were correlated with all subscale scores of the Japanese version of the Schizophrenia Quality of Life Scale (JSQLS). Stepwise regression showed that negative symptoms, psychological discomfort, and resistance predicted the dysfunction of psycho-social activity score and the dysfunction of motivation and energy score on the JSQLS. This study shows that active treatment for negative symptoms, psychological discomfort, and resistance should be recommended to improve QOL among inpatients with schizophrenia.

Semantic clustering of category fluency in schizophrenia examined with singular value decomposition

Decreased productivity on verbal fluency tasks by persons with schizophrenia has been attributed to semantic system abnormalities. Semantic structure is often assessed using multidimensional scaling (MDS) to detect normal and aberrant semantic clustering. However, MDS has limitations that may be particularly problematic for such assessments. Here, we introduce a different clustering technique, singular value decomposition (SVD), to elucidate abnormalities of the semantic system in schizophrenia. We compared 102 treated outpatients with schizophrenia to 109 healthy adults on two category-cued word fluency tasks. Patients with schizophrenia showed semantic clustering patterns that differ markedly from those of healthy adults. However, SVD revealed more detailed and critical semantic system abnormalities than previously appreciated using MDS. Patients with schizophrenia showed less coherent semantic clustering of both low- and high-frequency category exemplars than healthy adults. These results suggest the intriguing possibility that impaired automatic activation of semantic information is a key deficit in schizophrenia.

Associations of serum brain-derived neurotrophic factor with cognitive impairments and negative symptoms in schizophrenia

Brain-derived neurotrophic factor (BDNF) may be involved in the pathophysiology of schizophrenia. The aim of this study was to examine the associations of serum BDNF levels with the cognition and clinical characteristics in patients with schizophrenia. Sixty-three patients with schizophrenia and 52 age- and sex-matched healthy controls were examined with neuropsychological tests. Serum BDNF levels were determined by enzyme-linked immunosorbent assay (ELISA). There were no significant differences in serum BDNF levels between normal controls and patients with schizophrenia. Serum BDNF levels of normal controls showed negative correlations with verbal working memory, but this was not the case with schizophrenic patients. Meanwhile, serum BDNF levels of schizophrenic patients showed positive correlations with the scores of the Scale for the Assessment of Negative Symptoms (SANS) and the Information subtest scores of Wechsler Adult Intelligence Scale Revised (WAIS-R). Serum BDNF levels are related with the impairment of verbal working memory and negative symptoms in patients with schizophrenia.

Differential pattern of semantic memory organization between bipolar I and II disorders

Semantic cognition is one of the key factors in psychosocial functioning. The aim of this study was to explore the differences in pattern of semantic memory organization between euthymic patients with bipolar I and II disorders using the category fluency task. Study participants included 23 euthymic subjects with bipolar I disorder, 23 matched euthymic subjects with bipolar II disorder and 23 matched control subjects. All participants were assessed for verbal learning, recall, learning strategies, and fluency. The combined methods of hierarchical clustering and multidimensional scaling were used to compare the pattern of semantic memory organization among the three groups. Quantitative measures of verbal learning, recall, learning strategies, and fluency did not differ between the three groups. A two-cluster structure of semantic memory organization was identified for the three groups. Semantic structure was more disorganized in the bipolar I disorder group compared to the bipolar II disorder. In addition, patients with bipolar II disorder used less elaborate strategies of semantic memory organization than those of controls. Compared to healthy controls, strategies for categorization in semantic memory appear to be less knowledge-based in patients with bipolar disorders. A differential pattern of semantic memory organization between bipolar I and II disorders indicates a higher risk of cognitive abnormalities in patients with bipolar I disorder compared to patients with bipolar II disorder. Exploring qualitative nature of neuropsychological domains may provide an explanatory insight into the characteristic behaviors of patients with bipolar disorders.

The relationship between atypical semantic activation and odd speech in schizotypy across emotionally evocative conditions

INTRODUCTION

Odd speech is prevalent in individuals with schizotypy compared to controls and this odd speech is particularly pronounced under stress-induced conditions. Despite a number of research studies that have examined odd speech, the mechanisms underlying this phenomenon remain unclear. There is reason to suspect that the increase in odd speech observed in schizotypy may reflect atypical semantic activation patterns, defined in terms of increased activation of weakly associated words within the semantic network.

METHODS

In this study, we compared atypical semantic activation in individuals with a broad set of cognitive-perceptual, interpersonal and disorganization schizotypal traits (n=83) and controls (n=23). Odd speech was measured using a behavior-based analysis of natural speech procured from a laboratory speech-task involving separate experimentally manipulated stressful, pleasant, and neutral conditions.

RESULTS

The schizotypy and control groups did not differ in semantic activation, but atypical semantic activation was more pronounced in individuals with disorganization traits and attenuated in those with interpersonal traits. Interestingly, the relationship between semantic activation and odd speech was observed for the stressful, but not pleasant or neutral conditions in the schizotypy group.

CONCLUSIONS

These findings suggest that individuals with schizotypy may be able to inhibit atypical associations in nonstressful situations. However, their ability to prevent atypical semantic activation from affecting speech may be disrupted under stress, thus resulting in more odd speech. This study also highlights the dramatic differences in semantic activation across the various manifestations of schizotypy.

The influence of 5-HTT and COMT genotypes on verbal fluency in ecstasy users

Deficits in verbal fluency associated with ecstasy use have been well established; however, the mechanisms underlying this impairment have yet to be elucidated. In this study we investigated for the first time whether there was a disproportionate impairment in two cognitive subcomponents of verbal fluency: clustering (ability to generate words within the same subcategory) and switching (ability to change the subcategory). We also investigated a possible association between ecstasy use and verbal fluency in subjects genotyped for 5-HTT (5-HTTLPR and 5-HTTVNTR) and COMT (val(108/158)met, rs165599 and rs2097603) polymorphisms, in order to find a potential implication of genetic factors. Ecstasy polydrug users (n = 30) and non-ecstasy users (n = 41) were evaluated in both semantic and phonemic fluency. Results showed that ecstasy users had poorer semantic (but not phonemic) fluency performance than controls. Detailed analysis of clustering and switching performance revealed that this impairment was associated with poorer clustering mechanisms. Clustering was also modulated by the COMT rs165599 polymorphism independently of the group. A specific effect of the 5-HTTLPR polymorphism on switching performance was also found, with ss carriers performing significantly worse than ls and ll carriers, suggesting a serotonin modulation of frontal-executive flexibility. Based on the impaired clustering and switching strategies observed in ecstasy users, it might be proposed that both semantic knowledge and retrieval are impaired in this population. The verbal fluency deficit in ecstasy users may be attributable to a disruption of frontal-striatal circuits directly related with the serotonin function as well as a depletion of lexical-semantic stores mediated by temporal structures.

Is semantic memory impaired in schizophrenia? A systematic review and meta-analysis of 91 studies

INTRODUCTION

Semantic memory impairments in schizophrenia have been reported across a wide range of neuropsychological tests. Set against a backdrop of fairly widespread cognitive impairments, it is difficult to know whether there is a primary, or secondary, impairment of semantic memory in schizophrenia. Also, whether there is a profile of differential impairment across the range of neuropsychological tests.

METHODS

Employing a systematic search strategy, 91 papers were identified which have assessed participants with schizophrenia on a measure of semantic memory. A series of meta-analyses were then conducted which provided combined weighted means for performance on tasks of naming, word-picture matching, verbal fluency, priming, and categorisation.

RESULTS

An uneven profile of impairment is reported with large effect sizes for tests of naming and verbal fluency, medium effect sizes for word-picture matching and association and small effect sizes for categorisation and priming tests.

CONCLUSIONS

This uneven profile supports the claim that a degradation of semantic knowledge may not be adequate in explaining the semantic memory impairment in schizophrenia. This conclusion is supported by the data which report a relationship between an executive dysfunction and poor priming and fluency performance particularly. The data support a link between Formal Thought Disorder and semantic memory impairments on tests of naming and verbal fluency but on other tests evidence is equivocal.

Specific metabolites in the medial prefrontal cortex are associated with the neurocognitive deficits in schizophrenia: a preliminary study

We measured brain metabolites in the medial prefrontal cortex of 19 schizophrenic patients and 18 healthy controls by 3 T proton magnetic resonance spectroscopy ((1)H MRS), and examined the relationship between prefrontal cortex-related neurocognitive functions and brain metabolites in the medial prefrontal cortex. The patients with schizophrenia exhibited deficits on the verbal fluency, Wisconsin card sorting test (WCST), trail making test, Stroop test and digit span distraction test (DSDT), but not on the Iowa gambling test. The patients showed statistical significant changes in the ratio of glutamine/glutamate, the ratio of N-acetyl-l-aspartate (NAA)/glycerophosphorylcholine plus phosphorylcholine (GPC+PC) and the levels of taurine in the medial prefrontal cortex compared with normal controls. Furthermore, we found significant correlations of the ratio of glutamine/glutamate with WCST and DSDT scores, the ratio of NAA/(GPC+PC) with verbal fluency and WCST scores, and the levels of taurine with scores on the Stroop test and Trail making test A among the participants. The ratios of NAA/(GPC+PC) and (GPC+PC)/(Cr+PCr) had significant relationships with the duration of untreated psychosis of the schizophrenic patients. The glutamine/glutamate ratio and levels of taurine were significantly related to the duration of illness of the patients. These data suggest that specific metabolites of the medial prefrontal cortex are associated with the neurocognitive deficits in schizophrenia.

Verbal fluency, semantics, context and symptom complexes in schizophrenia

Lexical-semantic access and retrieval was examined in 15 adults diagnosed with schizophrenia and matched controls. This study extends the literature through the inclusion of multiple examinations of lexical-semantic production within the same patient group and through correlating performance on these tasks with various positive and negative clinical symptoms. On tasks of verbal fluency, meaning generation, sentence production using contextual information and confrontation naming, participants with schizophrenia made significantly more semantic errors on naming tasks; produced fewer meanings for homophones; produced fewer items on semantic, phonological, cued and switching fluency tasks; and produced more errors on sentence production tasks when compared to healthy controls. Significant correlations were also observed between ratings of psychomotor poverty and measures of semantic production and mental inflexibility. This study has provided additional evidence for deficits in lexical-semantic retrieval which are not due to underlying semantic store degradation, do not involve phonological based retrieval, and at the level of sentence generation appear to vary as a function of the contextual constraints provided.

The effects of galantamine on psychopathology in chronic stable schizophrenia

OBJECTIVES

Galantamine is an acetylcholinesterase inhibitor and an allosteric modulator of the alpha4beta2 and alpha7 nicotinic receptors. There are several case reports describing the potential benefits of galantamine for negative symptoms associated with schizophrenia. This secondary analysis describes the effects of galantamine on psychopathology in people with schizophrenia.

METHODS

Subjects with clinically stable chronic schizophrenia were randomized to adjunctive galantamine (24 mg/d) or placebo in a 12-week double-blind trial. Symptomatology was assessed with the Brief Psychiatric Rating Scale (BPRS) and the Clinical Global Impression Scale. The Scale for the Assessment of Negative Symptoms (SANS) was used to measure negative symptoms.

RESULTS

Eighty-six patients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of schizophrenia or schizoaffective disorder taking a stable dose of antipsychotic medications were randomized to adjunctive treatment with study drug (galantamine, n = 42; placebo, n = 44); 73 subjects completed the study (galantamine, n = 35; placebo, n = 38). No significant differences were found on BPRS total score (P = 0.585) or BPRS subfactor scores. Scale for the Assessment of Negative Symptoms total scores also did not decrease significantly (P = 0.106) in either group; however, galantamine treatment was associated with a greater benefit in the SANS subfactor, alogia (P = 0.007).

CONCLUSIONS

The lack of robust significant effects of galantamine on negative, and other symptom domains, may be due to the relatively low baseline level of these symptoms in the tested population. Galantamine may have some benefit on certain negative symptoms, particularly alogia. Studies specifically designed to address the issue of the efficacy of galantamine for negative symptoms are needed to confirm this observation.

Semantic memory deficits based on category fluency performance in schizophrenia: similar impairment patterns of semantic organization across Turkish and Japanese patients

Patients with schizophrenia exhibit a wide range of cognitive dysfunction, including impairments in semantic memory and verbal fluency. Previous studies report that semantic memory, i.e. associated meaning of words or knowledge, is specifically disorganized in patients who use the English or Japanese language. The purpose of the present study was to determine if semantic memory, as evaluated by verbal fluency data, shows similar patterns of semantic disorganization in non-English-speaking patients who do (Turkish) or do not (Japanese) use an alphabetical language. Turkish (N=20) and Japanese (N=22) patients with schizophrenia, as well as Japanese normal controls (N=22), entered the study. As a measure of semantic memory organization, two types of cluster analyses, i.e. ADDTREE and hierarchical cluster analysis, were performed on category fluency task data. The cluster analyses revealed a greater similarity between the Turkish patients vs. Japanese patients comparison than the Japanese patients vs. Japanese controls comparison. The results provide further support to the concept that impaired semantic memory organization is one of the core features of schizophrenia, and is independent of the language system or cultural backgrounds.

Acute and chronic effects of ketamine on semantic priming: modeling schizophrenia?

Acute administration of the N-methyl-D-aspartate receptor antagonist ketamine induces schizophrenia-like symptoms in healthy volunteers; furthermore, a window on ketamine's chronic effects is provided by regular recreational users. The current study utilized both acute ketamine administration in healthy volunteers and chronic ketamine abusers to investigate semantic processing, one of the key cognitive deficits in schizophrenia. Semantic processing was examined using a semantic priming paradigm. In experiment 1, acute effects of low (75 ng/mL) and high (150 ng/mL) ketamine doses were compared in a placebo-controlled double-blind independent group design with 48 participants. In experiment 2, 19 regular recreational ketamine users were compared with 19 ketamine-naive polydrug controls and 26 non-drug-using controls. In both experiments, semantic priming parameters were manipulated to distinguish between ketamine's effects on (1) automatic and strategic processing and (2) the facilitation and inhibition components of semantic priming for strongly (directly) related primes and targets. Acute effects of ketamine on semantic priming for weakly (indirectly) related primes and targets were also assessed in experiment 1. Acutely, ketamine impaired the employment of strategic mechanisms but not automatic processing within both the direct and indirect semantic priming tasks. Acute ketamine administration also induced clear schizophrenia-like symptoms. Schizotypy traits in the cognitive and perceptual domains tended to correlate with increased semantic priming in long-term ketamine users. In summary, acute and chronic ketamine-induced changes partially mirrored the findings on semantic priming in schizophrenia.

Apathy is associated with executive functioning in first episode psychosis

BACKGROUND

The underlying nature of negative symptoms in psychosis is poorly understood. Investigation of the relationship between the different negative subsymptoms and neurocognition is one approach to understand more of the underlying nature. Apathy, one of the subsymptoms, is also a common symptom in other brain disorders. Its association with neurocognition, in particular executive functioning, is well documented in other brain disorders, but only studied in one former study of chronic patients with schizophrenia. This study investigates the association between apathy and neurocognitive functioning in patients with first episode psychosis (FEP), with the hypothesis that apathy is more associated with tests representing executive function than tests representing other neurocognitive domains.

METHODS

Seventy-one FEP patients were assessed with an extensive neuropsychological test battery. Level of apathy was assessed with the abridged Apathy Evaluation Scale (AES-C-Apathy).

RESULTS

AES-C-Apathy was only significantly associated with tests from the executive domain [Semantic fluency (r = .37, p < .01), Phonetic fluency (r = .25, p < .05)] and working memory [Letter Number Span (r = .26; p =< .05)]; the first two representing the initiation part of executive function. Confounding variables such as co-occuring depression, positive symptoms or use of antipsychotic medication did not significantly influence the results.

CONCLUSION

We replicated in FEP patients the relationship between apathy and executive functioning reported in another study for chronic patients with schizophrenia. We also found apathy in FEP to have the same relationship to executive functioning, as assessed with the Verbal fluency tests, as that reported in patients with other brain disorders, pointing to a common underlying nature of this symptom across disorders.

Negative correlation between brain glutathione level and negative symptoms in schizophrenia: a 3T 1H-MRS study

Background

Glutathione (GSH), a major intracellular antioxidant, plays a role in NMDA receptor-mediated neurotransmission, which is involved in the pathophysiology of schizophrenia. In the present study, we aimed to investigate whether GSH levels are altered in the posterior medial frontal cortex of schizophrenic patients. Furthermore, we examined correlations between GSH levels and clinical variables in patients.

Methods and Findings

Twenty schizophrenia patients and 16 age- and gender-matched normal controls were enrolled to examine the levels of GSH in the posterior medial frontal cortex by using 3T SIGNA EXCITE ¹H-MRS with the spectral editing technique, MEGA-PRESS. Clinical variables of patients were assessed by the Global Assessment of Functioning (GAF), Scale for the Assessment of Negative Symptoms (SANS), Brief Psychiatric Rating Scale (BPRS), Drug-Induced Extra-Pyramidal Symptoms Scale (DIEPSS), and five cognitive performance tests (Word Fluency Test, Stroop Test, Trail Making Test, Wisconsin Card Sorting Test and Digit Span Distractibility Test). Levels of GSH in the posterior medial frontal cortex of schizophrenic patients were not different from those of normal controls. However, we found a significant negative correlation between GSH levels and the severity of negative symptoms (SANS total score and negative symptom subscore on BPRS) in patients. There were no correlations between brain GSH levels and scores on any cognitive performance test except Trail Making Test part A.

Conclusion

These results suggest that GSH levels in the posterior medial frontal cortex may be related to negative symptoms in schizophrenic patients. Therefore, agents that increase GSH levels in the brain could be potential therapeutic drugs for negative symptoms in schizophrenia.

Essential polyunsaturated fatty acids and social cognition in schizophrenia

Abnormal metabolism of essential polyunsaturated fatty acids (EPUFAs), a component of phospholipids in neural membranes, has been suggested to be related to the pathophysiology of schizophrenia. The purpose of this study was to examine the relationship between EPUFA concentrations in erythrocyte membranes, a peripheral measure of phospholipid composition in the brain, and clinical variables, such as cognitive performance relevant to social functions, in patients with schizophrenia. Erythrocyte membrane levels of EPUFAs, saturated fatty acids, and monounsaturated acids were measured in 25 patients with schizophrenia and 32 age- and gender-matched 32 normal volunteers. The script tasks, a measure of social cognition, and the Brief Psychiatric Rating Scale were administered to the patients. The levels of EPUFAs, but not those of saturated or monosaturated fatty acids, were significantly lower in patients than in normal controls. The degree of a decrease in EPUFA levels was positively correlated with severity of positive symptoms and impairment of frequency judgment performance on the script tasks, while no such correlations were found with negative symptoms, attention as measured by the Wechsler Adult Intelligence Scale-Revised-Digit Span, or verbal memory as measured by the Auditory Verbal Learning Test. These results provide the first suggestion for a contribution of decreased levels of EPUFAs to impaired social cognition, as represented by event schema, in patients with schizophrenia.

Brief assessment of cognition in schizophrenia: validation of the Japanese version

This preliminary study was performed to test the reliability and validity of the Brief Assessment of Cognition in Schizophrenia (BACS) as an assessment tool in a Japanese-language version (BACS-J). The subjects for the present study were 30 outpatients with chronic schizophrenia. Each subject gave written informed consent to participate in the research. Cronbach's alpha for the BACS-J was 0.77. The BACS-J composite score was significantly correlated with all primary measures of BACS-J (verbal memory, working memory, motor speed, verbal fluency, attention, and executive function). All BACS-J primary measures and the composite score were significantly correlated between two assessments. The mean score of the Digit Sequencing Task and composite score on the second assessment were significantly larger than those on the first assessment. All BACS-J primary measures except the Symbol Coding Task were significantly correlated with relevant standard neurocognitive tests. Also, the BACS-J composite score was significantly correlated with all standard neurocognitive tests except the Continuous Performance Test. A principal components analysis with varimax rotation resulted in a three-factor solution (executive function and memory; motor speed and general cognitive functions; and working memory). This preliminary study indicates that the BACS-J is a reliable and practical scale to evaluate cognitive function.

Verbal memory deficits in a preadolescent case of lesions of the left parahippocampal gyrus associated with a benign tumor

The authors report cognitive functions of a 13-year-old boy with a cavernous angioma occupying the posterior left parahippocampal gyrus (PHG) and part of the left fusiform gyrus but not hippocampus. Neuropsychological examinations soon after the removal of the tumor showed selective deficits in semantic memory function, as evaluated by the Category Fluency Task and the Wechsler Memory Scale-Revised, while visual memory, attention, and IQ were not affected. These observations suggest the involvement of the PHG in the processing of semantic memory and provide an insight into the neural substrates underlying the distinct cognitive deficits in some of the psychiatric diseases such as schizophrenia.