Eric F.C. Cheung

Impaired facial emotion perception in schizophrenia: a meta-analysis.

Research into facial emotion perception in schizophrenia has burgeoned over the past several decades. The evidence is mixed regarding whether patients with schizophrenia have a general facial emotion perception deficit (a deficit in facial emotion perception plus a more basic deficit in facial processing) or specific facial emotion perception deficits (deficits only in facial emotion perception tasks). A meta-analysis is conducted of 28 facial emotion perception studies that include control tasks. These studies use differential deficit designs to examine whether patients with schizophrenia demonstrate a general deficit or specific deficit in facial emotion perception. A significant mean effect size is found for total facial emotion perception (d=-0.85). Patients with schizophrenia demonstrate impaired ability to perform corresponding control tasks, and the mean effect size is -0.70. The current findings suggest that patients with schizophrenia have moderately to severely impaired perception of facial emotion.

Motivational deficits in effort-based decision making in individuals with subsyndromal depression, first-episode and remitted depression patients

Anhedonia is a hallmark symptom of major depressive disorder (MDD). Preliminary findings suggest that anhedonia is characterized by reduced reward anticipation and motivation of obtaining reward. However, relatively little is known about reward-based decision-making in depression. We tested the hypothesis that anhedonia in MDD may reflect specific impairments in motivation on reward-based decision-making and the deficits might be associated with depressive symptoms severity. In study 1, individuals with and without depressive symptoms performed the modified version of the Effort Expenditure for Rewards Task (EEfRT), a behavioral measure of cost/benefit decision-making. In study 2, MDD patients, remitted MDD patients and healthy controls were recruited for the same procedures. We found evidence for decreased willingness to make effort for rewards among individuals with subsyndromal depression; the effect was amplified in MDD patients, but dissipated in patients with remitted depression. We also found that reduced anticipatory and consummatory pleasure predicted decreased willingness to expend efforts to obtain rewards in MDD patients. For individuals with subsyndromal depression, the impairments were correlated with anticipatory anhedonia but not consummatory anhedonia. These data offer novel evidence that motivational deficits in MDD are correlated with depression severity and predicted by self-reported anhedonia.

Revisiting the therapeutic effect of rTMS on negative symptoms in schizophrenia: A meta-analysis

This study sought to determine the moderators in the treatment effect of repetitive transcranial magnetic stimulation (rTMS) on negative symptoms in schizophrenia. We performed a meta-analysis of prospective studies on the therapeutic application of rTMS in schizophrenia assessing the effects of both low-frequency and high-frequency rTMS on negative symptoms. Results indicate that rTMS is effective in alleviating negative symptoms in schizophrenia. The effect size was moderate (0.63 and 0.53, respectively). The effect size of rTMS on negative symptoms in sham-controlled trials was 0.80 as measured by the SANS and 0.41 as measured by the PANSS. A longer duration of illness was associated with poorer efficacy of rTMS on negative symptoms. A 10 Hz setting, at least 3 consecutive weeks of treatment, treatment site at the left dorsolateral prefrontal cortex (DLPFC) and a 110% motor threshold (MT) were found to be the best rTMS parameters for the treatment of negative symptoms. The results of our meta-analysis suggest that rTMS is an effective treatment option for negative symptoms in schizophrenia. The moderators of rTMS on negative symptoms included duration of illness, stimulus frequency, duration of illness, position and intensity of treatment as well as the type of outcome measures used.

The influence of anhedonia on feedback negativity in major depressive disorder.

Anhedonia is associated with reward-processing deficits of the dopamine system, which may increase the risk of depression. Nevertheless, few previous studies have examined the influence of hedonic tone on event-related potential (ERP) measures of reward processing in major depressive disorder. A simple gambling task was used to elicit feedback negativity (FN), an ERP component elicited by feedback indicating gain versus loss, in 27 patients with major depression and 27 healthy participants. We found that participants with depression were characterized by reduced FN responses, especially towards monetary gains, but not losses, compared with healthy individuals. In addition, the amplitude of FN to gain feedback in participants with depression was related to anhedonia severity and depressive symptoms. These findings indicate an association between low hedonic capacity and reduction in FN. As a neural measure of reward sensitivity, FN may be generated in part by reward-related activity.

The components of executive functioning in a cohort of patients with chronic schizophrenia : A multiple single-case study design

We examined the fractionation of executive functioning performance in ninety patients with schizophrenia, who were tested for initiation, sustained attention, switching/flexibility, attention allocation and impulsivity/disinhibition. The participants were also given tests of general intelligence and memory. We analysed the executive functioning performance of individual patients against normative data from our laboratory, and summary scores for all of the executive functioning components were computed. For each component, participants were classified as having impairment with a test performance of 1.5 standard deviations or more from the norm of the corresponding test. Of all of the participants, 27.8% (n=25) demonstrated poor performance in all of the components, and 5.6 % (n=5) exhibited intact or fair performance in all of the components. Furthermore, 18.9% (n=17) showed intact or fair performance in one component, 16.7% (n=15) in two components, 21.1% (n=19) in three components and 10% (n=9) in four components. The groups did not differ in education, gender or duration of illness, but the group that showed impaired performance in all of the components demonstrated the most severe psychotic symptoms after controlling for background intelligence, age and medication. The differential breakdown for the executive functioning performance across the participants suggests that the fractionation of central executive functioning occurs in schizophrenia.

Neurological soft signs discriminate schizophrenia from major depression but not bipolar disorder.

BACKGROUND Neurological soft signs (NSS) are minor neurological abnormalities, including motor, sensory, and inhibitory dysfunction. Schizophrenia and other neuropsychiatric disorders are associated with a higher prevalence of NSS. However, the relationships between NSS and schizophrenia, bipolar disorder, and major depression are unclear. The present study aimed to examine the specificity of NSS among these three clinical groups. METHOD A total of 120 demographically matched participants (30 each in schizophrenia, bipolar disorder, major depression, and healthy controls) were recruited for the study. NSS subscales of the Cambridge Neurological Inventory (CNI) were administered to each participant. RESULTS Significant differences were found in the total score of NSS (p<0.01), and the subscale scores for motor coordination (p<0.01), sensory integration (p=0.01) and disinhibition (p<0.01). Both patients with schizophrenia and bipolar disorder showed more total NSS signs than healthy controls (p<0.01). Patients with schizophrenia also showed more total NSS signs than patients with major depression (p=0.02). Both patients with schizophrenia and patients with bipolar disorder showed more motor coordination signs than healthy controls and patients with major depression (p<0.05). Moreover, compared with healthy controls, patients with schizophrenia showed more disinhibition signs (p<0.01), while patients with bipolar disorder showed more sensory integration signs (p<0.01). Discriminant analysis showed 77.5% of correct classification of patients with schizophrenia and bipolar disorder from patients with major depression and healthy controls. CONCLUSIONS NSS are not unique to schizophrenia, but are also found in bipolar disorder, while patients with major depression are comparable to normal controls. Our results suggest that NSS, especially motor-coordination signs, can differentiate schizophrenia from major depression but not bipolar disorder. Our results may provide further evidence to support the similarity between schizophrenia and bipolar disorder from the dimension of behavioral expression.

Recovery in Hong Kong: Service user participation in mental health services

Abstract This article provides an overview of mental health services (MHS) and the application of the recovery concept in Hong Kong, focusing on user participation. It presents stakeholders’ views of the recovery movement in a round-table discussion format, demonstrating agreement that user participation merits more public and official attention. Some of the present difficulties with the movement are also reviewed. Social identity theory (SIT) is then analysed as a potentially useful framework for theorizing how service users’ identities change as they become service providers. The paper then provides an overview of the current financial and political position of MHS, and identifies signs that the recovery approach is becoming accepted. It also addresses the cultural meanings of the concept, and sets out examples of its implementation in the health and social welfare sectors. Lastly, it summarizes the challenges facing service providers and users and concludes that as the recovery movement is still in its infancy in Hong Kong, more coordinated efforts are needed to establish the organizational support and policy framework, so that sustainable and evidence-based service provision can be achieved.

Semantic processing disturbance in patients with schizophrenia: a meta-analysis of the N400 component.

Background Theoretically semantic processing can be separated into early automatic semantic activation and late contextualization. Semantic processing deficits have been suggested in patients with schizophrenia, however it is not clear which stage of semantic processing is impaired. We attempted to clarify this issue by conducting a meta-analysis of the N400 component. Methods Twenty-one studies met the inclusion criteria for the meta-analysis procedure. The Comprehensive Meta-Analysis software package was used to compute pooled effect sizes and homogeneity. Results Studies favoring early automatic activation produced a significant effect size of −0.41 for the N400 effect. Studies favoring late contextualization generated a significant effect size of −0.36 for the N400 effect, a significant effect size of −0.52 for N400 for congruent/related target words, and a significant effect size of 0.82 for the N400 peak latency. Conclusion These findings suggest the automatic spreading activation process in patients with schizophrenia is very similar for closely related concepts and weakly or remotely related concepts, while late contextualization may be associated with impairments in processing semantically congruent context accompanied by slow processing speed.

Common Variants on Xq28 Conferring Risk of Schizophrenia in Han Chinese

Schizophrenia is a highly heritable, severe psychiatric disorder affecting approximately 1% of the world population. A substantial portion of heritability is still unexplained and the pathophysiology of schizophrenia remains to be elucidated. To identify more schizophrenia susceptibility loci, we performed a genome-wide association study (GWAS) on 498 patients with schizophrenia and 2025 controls from the Han Chinese population, and a follow-up study on 1027 cases and 1005 controls. In the follow-up study, we included 384 single nucleotide polymorphisms (SNPs) which were selected from the top hits in our GWAS (130 SNPs) and from previously implicated loci for schizophrenia based on the SZGene database, NHGRI GWAS Catalog, copy number variation studies, GWAS meta-analysis results from the international Psychiatric Genomics Consortium (PGC) and candidate genes from plausible biological pathways (254 SNPs). Within the chromosomal region Xq28, SNP rs2269372 in RENBP achieved genome-wide significance with a combined P value of 3.98 × 10(-8) (OR of allele A = 1.31). SNPs with suggestive P values were identified within 2 genes that have been previously implicated in schizophrenia, MECP2 (rs2734647, P combined = 8.78 × 10(-7), OR = 1.28; rs2239464, P combined = 6.71 × 10(-6), OR = 1.26) and ARHGAP4 (rs2269368, P combined = 4.74 × 10(-7), OR = 1.25). In addition, the patient sample in our follow-up study showed a significantly greater burden for pre-defined risk alleles based on the SNPs selected than the controls. This indicates the existence of schizophrenia susceptibility loci among the SNPs we selected. This also further supports multigenic inheritance in schizophrenia. Our findings identified a new schizophrenia susceptibility locus on Xq28, which harbor the genes RENBP, MECP2, and ARHGAP4.

An Association Study of RGS4 Polymorphisms With Clinical Phenotypes of Schizophrenia in a Chinese Population

The regulator of G‐protein signaling 4 (RGS4) has been suggested as a candidate gene for schizophrenia. However, following an initial positive report, subsequent association studies between RGS4 and schizophrenia have yielded inconclusive results. Also, few studies have investigated the association of RGS4 polymorphisms with the phenotypic subgroups of schizophrenia. To further clarify the role of RGS4 in this disease, we performed a case‐control study (504 cases and 531 controls of Han Chinese descent) to examine the association of RGS4 with schizophrenia and with clinical and neurocognitive profiles. The four markers (SNPs 1, 4, 7, and 18) implicated in the original association study were genotyped. We detected significant association of four‐marker haplotypes with schizophrenia (UNPHASED: global P = 0.037; PHASE: global P = 0.048). The haplotype G‐G‐G‐G, which was implicated in at least three previous studies, was the major risk haplotype (UNPHASED: P = 0.019; PHASE: P = 0.010). Regarding the clinical phenotypes, the Wechsler Adult Intelligence Test (WAIS) information subtest score was associated with SNP4 genotypes (P = 0.001). PANSS total and global psychopathology scores were also associated with SNP4, but may not reliably reflect the general severity of disease as the scores may be affected by confounders like medication response. Our study provides further support for a role of RGS4 in the pathogenesis of schizophrenia. We identified G‐G‐G‐G as the risk haplotype in our Chinese sample. The association with information subtest score suggests an effect of RGS4 on premorbid functioning, which may be related to neurodevelopmental processes. Further independent studies are required to verify our findings.