Bridge centrality network structure of negative symptoms in people with schizophrenia.

Negative symptoms are complex psychopathology. Although evidence generally supported the NIMH five consensus domains, research seldom examined measurement invariance of this model, and domain-specific correspondence across multiple scales. This study aimed to examine the interrelationship between negative symptom domains captured by different rating scales, and to examine the domain-specific correspondence across multiple scales. We administered the Brief Negative Symptom Scale (BNSS), the Self-evaluation of Negative Symptoms (SNS), and the Scale for Assessment of Negative Symptoms (SANS) to 204 individuals with schizophrenia. We used network analysis to examine the interrelationship between negative symptom domains. Besides regularized partial correlation network, we estimated bridge centrality indices to investigate domain-specific correspondence, while taking each scale as an independent community. The regularized partial correlation network showed that the SNS nodes clustered together, whereas the SANS and the BNSS nodes intermingled together. The SANS attention domain lied at the periphery of the network according to the Fruchterman-Reingold algorithm. The SANS anhedonia-asociality (strength = 1.48; EI = 1.48) and the SANS affective flattening (strength = 1.06; EI = 1.06) had the highest node strength and EI. Moreover, the five nodes of the BNSS bridged the nodes of the SANS and the SNS. BNSS blunted affect (strength = 0.76; EI = 0.76) and SANS anhedonia-asociality (strength = 0.76; EI = 0.74) showed the highest bridge strength and bridge EI. The BNSS captures negative symptoms and bridges the symptom domains measured by the SANS and the SNS. The three scales showed domain-specific correspondence.

Latent structure of self-report negative symptoms in patients with schizophrenia: A preliminary study.

INTRODUCTION: Negative symptoms are associated with poor outcomes and functioning. Latent structure of negative symptoms is important for identifying potential intervention targets for novel treatments. Self-report instruments have been developed to measure negative symptoms. Previous findings on latent structure of negative symptoms are inconsistently and mainly rely on clinician-rated instruments. METHOD: We aimed to explore the latent structure of the Self-Evaluation of Negative Symptoms Scale (SNS) in 204 clinically-stable outpatients with schizophrenia. Confirmatory factor analysis (CFA) was used to compare the competing models (i.e., one-factor, two-factor and five-factor models), and estimated goodness-of-fit indexes. Other clinician-rated scales for psychopathology and medication side-effects were also collected. RESULTS: The CFA found the five-factor model performing best, with a comparative fit index (CFI) of > 0.95, a Tucker Lewis Index (TLI) of > 0.95, and a root mean square error of approximation (RMSEA) of < 0.06. The robust chi-square difference test for the weighted least squares with mean and variance adjusted estimation (WLSMV) also indicated a significant better fit for the five-factor model. DISCUSSION: Our preliminary findings support a five-factor latent structure of self-report negative symptoms in schizophrenia patients. Further research in this area should utilize multiple clinician-rated and self-report measures, and recruit large and homogeneous samples with schizophrenia.

The benefits of emotionally salient cues on event-based prospective memory in bipolar patients and schizophrenia patients.

Prospective memory (PM) refers to the ability to remember to carry out a delayed intention in the future. Evidence suggests that emotionally salient cues can enhance PM functions in healthy population, but whether the benefit exists in schizophrenia and bipolar patients remains unclear. This study aimed to examine and compare the potential enhancement effect of emotional PM cues in schizophrenia patients and bipolar patients. Twenty-eight clinically stable schizophrenia participants, 26 euthymic bipolar participants and 29 controls completed a computerized PM task involving PM cues with different types of valences (i.e., positive, neutral and negative). All the three groups showed better PM performance when negative PM cues were presented compared with positive and neutral PM cues. The sizes of the enhancement effects of negative PM cues were large (all Cohen's d ≥ 1.00) and comparable across three groups. Our findings suggested that patients with schizophrenia and bipolar disorders could benefit from negative PM cues to an extent similar to healthy individuals, thus extended the notion of psychosis continuum to the important area of emotion-cognition interaction.

Consensus statements on the clinical usage and characteristics of aripiprazole for Hong Kong.

Aripiprazole, a dopamine partial agonist, is a second-generation anti-psychotic that is widely used for the treatment of schizophrenia and other psychotic disorders. A group of psychiatric experts in Hong Kong developed a set of consensus statements, aiming to facilitate the understanding of clinical properties and usages of aripiprazole among local physicians. Of note, because aripiprazole long-acting injectable has been available locally not long before the establishment of the consensus panel, which limited the discussion on its use in the local context, the consensus statements were focused primarily on oral aripiprazole. To draft the consensus statements, the panellists discussed the published evidence and their clinical experience regarding aripiprazole in a series of meetings based on several areas. At the final meeting, each drafted statement was voted on anonymously by all panellists based on its practicability of recommendation in Hong Kong. A set of consensus statements on the characteristics and clinical use of aripiprazole was established and accepted by the panel. These statements serve to provide a practical reference for physicians in Hong Kong, and possibly other parts of the Asia-Pacific region, on the use of aripiprazole in people with schizophrenia spectrum disorders and other psychotic problems.

Impaired olfactory identification and hedonic judgment in schizophrenia patients with prominent negative symptoms.

Introduction: Evidence suggests that schizophrenia patients have olfactory dysfunctions, but the relationship between olfactory identification, hedonic judgement, and negative symptomatology remains unclear. Few studies have investigated whether co-activation of pleasant and unpleasant emotions are more prevalent in schizophrenia patients.Methods: Thirty schizophrenia outpatients with prominent negative symptoms (PNS), 30 outpatients without PNS, and 30 controls completed the University of Pennsylvania Smell Identification Test, and were asked to identify the odourants and to rate their emotions. The effects of gender and medications on olfactory function were examined.Results: Schizophrenia patients exhibited olfactory identification impairments, even after accounting for gender and medication effects. Patients with PNS demonstrated larger magnitude of deficit than those without. Patients with PNS reported less pleasure to positive-valenced odourants, and less unpleasantness to negative-valenced odourants than controls. Olfactory anhedonia in patients with PNS disappeared after controlling for medication effect. Schizophrenia patients do not exhibit affective ambivalence in olfaction.Conclusions: Schizophrenia patients with PNS exhibit deficits in olfactory identification and hedonic judgement, even after controlling for gender and medication effects. Our findings support the close relationship between olfactory dysfunctions and negative symptoms. Further studies should investigate the effect of dopamine-blocking agents on the olfactory hedonic judgment in schizophrenia patients.

Following Instructions in Patients With Schizophrenia: The Benefits of Actions at Encoding and Recall.

The ability to follow spoken instructions is important to everyday functioning but has seldom been studied in patients with schizophrenia (SZ). Recent evidence suggests that action-based processing may facilitate the ability to follow instructions, which relies largely on working memory. In this study, we tested the hypothesis that SZ patients may also benefit from action-based advantages in following instructions. Forty-eight clinically stable SZ patients and 48 demographic- and IQ-matched controls completed a following spoken instruction span task involving varied encoding and recall conditions. While SZ patients were impaired in the overall performance of following spoken instructions, this deficit could be attributed to working memory impairment. More importantly, SZ patients showed action-based advantages both at the encoding and retrieval stage to the same extent as healthy controls. Specifically, both healthy controls and SZ patients showed improved memory performance when they additionally performed the actions, or watched the experimenter carrying out the actions compared with simply listening to spoken instructions during the encoding stage. During the retrieval stage, memory was improved when they recalled the instructions by physical enactment compared with oral repetition. The present study provides the first empirical evidence for the impairment in the ability to follow instructions in SZ. We have shown that involving action-based processing in the encoding and retrieval stage facilitated memory of instructions, indicating that the enactment advantage in working memory also applies to SZ patients. These findings provide useful insights for clinical interventions and cognitive remediation for SZ patients.

CasExpress reveals widespread and diverse patterns of cell survival of caspase-3 activation during development in vivo.

Caspase-3 carries out the executioner phase of apoptosis, however under special circumstances, cells can survive its activity. To document systematically where and when cells survive caspase-3 activation in vivo, we designed a system, CasExpress, which drives fluorescent protein expression, transiently or permanently, in cells that survive caspase-3 activation in Drosophila. We discovered widespread survival of caspase-3 activity. Distinct spatial and temporal patterns emerged in different tissues. Some cells activated caspase-3 during their normal development in every cell and in every animal without evidence of apoptosis. In other tissues, such as the brain, expression was sporadic both temporally and spatially and overlapped with periods of apoptosis. In adults, reporter expression was evident in a large fraction of cells in most tissues of every animal; however the precise patterns varied. Inhibition of caspase activity in wing discs reduced wing size demonstrating functional significance. The implications of these patterns are discussed.

Olanzapine-induced diabetic ketoacidosis in a Chinese man.

We present a case report of a 22-year-old Chinese man with schizophrenia and dissocial personality disorder who was normoglycaemic before taking olanzapine. After commencing olanzapine he developed diabetic ketoacidosis and was managed in the intensive care unit of a general hospital. Olanzapine was stopped and replaced by haloperidol 5 mg/day. He was put on a strict 1500 kcal diabetic diet and required insulin injections to maintain a normal blood sugar level despite cessation of olanzapine for 4 months. Doctors prescribing olanzapine should be aware of the risk of diabetes mellitus. Baseline and regular monitoring of body weight, body mass index, and fasting blood glucose are essential to prevent serious consequences.

Clozapine alone versus clozapine and risperidone with refractory schizophrenia.

BACKGROUND: The treatment of schizophrenia with multiple antipsychotic drugs is common, but the benefits and risks are not known. METHODS: In a randomized, double-blind study, we evaluated patients with schizophrenia and a poor response to treatment with clozapine. The patients continued to take clozapine and were randomly assigned to receive eight weeks of daily augmentation with 3 mg of risperidone or with placebo. This course of treatment was followed by an optional 18 weeks of augmentation with risperidone. The primary outcome was reduction in the total score for severity of symptoms on the Positive and Negative Syndrome Scale (PANSS). The secondary outcomes included cognitive functioning. RESULTS: A total of 68 patients were randomly assigned to treatment. In the double-blind phase, the mean total score for the severity of symptoms decreased from baseline to eight weeks in both the risperidone and the placebo groups. There was no statistically significant difference in symptomatic benefit between augmentation with risperidone and placebo: 9 of 34 patients receiving placebo and 6 of 34 receiving risperidone responded to treatment (P=0.38). The mean difference in the change in PANSS scores from baseline to eight weeks between those receiving risperidone and those receiving placebo was 0.1 (95 percent confidence interval, -7.3 to 7.0). The verbal working-memory index showed a small decline in the risperidone group and a small improvement in the placebo group (P=0.02 for the comparison between the two groups in the change from baseline). The increase in fasting blood glucose levels was mildly greater in the risperidone group than in the placebo group (16.2 vs. 1.8 mg per deciliter [0.90 vs. 0.10 mmol per liter], P=0.04). The incidence and severity of other side effects did not differ between the two groups. CONCLUSIONS: In this short-term study, the addition of risperidone to clozapine did not improve symptoms in patients with severe schizophrenia. (ClinicalTrials.gov number, NCT00272584).