High-functioning autism patients share similar but more severe impairments in verbal theory of mind than schizophrenia patients.

BACKGROUND: Evidence suggests that autism and schizophrenia share similarities in genetic, neuropsychological and behavioural aspects. Although both disorders are associated with theory of mind (ToM) impairments, a few studies have directly compared ToM between autism patients and schizophrenia patients. This study aimed to investigate to what extent high-functioning autism patients and schizophrenia patients share and differ in ToM performance. METHODS: Thirty high-functioning autism patients, 30 schizophrenia patients and 30 healthy individuals were recruited. Participants were matched in age, gender and estimated intelligence quotient. The verbal-based Faux Pas Task and the visual-based Yoni Task were utilised to examine first- and higher-order, affective and cognitive ToM. The task/item difficulty of two paradigms was examined using mixed model analyses of variance (ANOVAs). Multiple ANOVAs and mixed model ANOVAs were used to examine group differences in ToM. RESULTS: The Faux Pas Task was more difficult than the Yoni Task. High-functioning autism patients showed more severely impaired verbal-based ToM in the Faux Pas Task, but shared similar visual-based ToM impairments in the Yoni Task with schizophrenia patients. CONCLUSIONS: The findings that individuals with high-functioning autism shared similar but more severe impairments in verbal ToM than individuals with schizophrenia support the autism-schizophrenia continuum. The finding that verbal-based but not visual-based ToM was more impaired in high-functioning autism patients than schizophrenia patients could be attributable to the varied task/item difficulty between the two paradigms.

Heritability and familiality of neurological soft signs: evidence from healthy twins, patients with schizophrenia and non-psychotic first-degree relatives.

BACKGROUND: Neurological soft signs (NSS) have long been considered potential endophenotypes for schizophrenia. However, few studies have investigated the heritability and familiality of NSS. The present study examined the heritability and familiality of NSS in healthy twins and patient-relative pairs. METHOD: The abridged version of the Cambridge Neurological Inventory was administered to 267 pairs of monozygotic twins, 124 pairs of dizygotic twins, and 75 pairs of patients with schizophrenia and their non-psychotic first-degree relatives. RESULTS: NSS were found to have moderate but significant heritability in the healthy twin sample. Moreover, patients with schizophrenia correlated closely with their first-degree relatives on NSS. CONCLUSIONS: Taken together, the findings provide evidence on the heritability and familiality of NSS in the Han Chinese population.

Altered corticostriatal functional connectivity in individuals with high social anhedonia.

BACKGROUND: Dysregulation of the striatum and altered corticostriatal connectivity have been associated with psychotic disorders. Social anhedonia has been identified as a predictor for the development of schizophrenia spectrum disorders. The aim of the present study was to examine corticostriatal functional connectivity in individuals with high social anhedonia. METHOD: Twenty-one participants with high social anhedonia score and 30 with low social anhedonia score measured by the Chinese version of the Revised Social Anhedonia Scale were recruited from university undergraduates (age 17-21 years) to undergo resting-state functional MRI scans. Six subdivisions of the striatum in each hemisphere were defined as seeds. Voxel-wise functional connectivity analyses were conducted between each seed and the whole brain voxels, followed by repeated-measures ANOVA for the group effect. RESULTS: Participants with high social anhedonia showed hyper-connectivity between the ventral striatum and the anterior cingulate cortex and the insula, and between the dorsal striatum and the motor cortex. Hypo-connectivity in participants with high social anhedonia was also observed between the ventral striatum and the posterior cingulate cortex. Partial correlation analyses further showed that the functional connectivity between the ventral striatum and the prefrontal cortex was associated with pleasure experience and emotional suppression. CONCLUSIONS: Our findings suggest that altered corticostriatal connectivity can be found in participants with high levels of social anhedonia. Since social anhedonia has been considered a predictor for schizophrenia spectrum disorders, our results may provide novel evidence on the early changes in brain functional connectivity in at-risk individuals.

The nature of anhedonia and avolition in patients with first-episode schizophrenia.

BACKGROUND: Patients with schizophrenia have intact ability to experience emotion, but empirical evidence suggests that they fail to translate emotional salience into effortful behaviour. Previous research in patients with chronic schizophrenia suggests that working memory is important in integrating emotion and behaviour. This study aimed to examine avolition and anhedonia in patients with first-episode schizophrenia and clarify the role of working memory in emotion-behaviour coupling. METHOD: We recruited 72 participants with first-episode schizophrenia and 61 healthy controls, and used a validated emotion-inducing behavioural paradigm to measure participants' affective experiences and how experienced emotion coupled with behaviour. Participants were given the opportunity to expend effort to increase or decrease their exposure to emotion-inducing photographs. Participants with schizophrenia having poor working memory were compared with those with intact working memory in their liking and emotion-behaviour coupling. RESULTS: Patients with first-episode schizophrenia experienced intact 'in-the-moment' emotion, but their emotion was less predictive of the effort expended, compared with controls. The emotion-behaviour coupling was significantly weaker in patients with schizophrenia with poor working memory than in those with intact working memory. However, compared with controls, patients with intact working also showed substantial emotion-behaviour decoupling. CONCLUSIONS: Our findings provide strong evidence for emotion-behaviour decoupling in first-episode schizophrenia. Although working memory deficits contribute to defective translation of liking into effortful behaviour, schizophrenia alone affects emotion-behaviour coupling.

The Hong Kong mental morbidity survey: background and study design.

Mental disorders are highly prevalent conditions with immense disease burden. To inform health and social services policy formulation, local psychiatric epidemiological data are required. The Hong Kong Mental Morbidity Survey is a 3-year population-based study in which 5700 community-dwelling Chinese adults aged between 16 and 75 years were interviewed with the aim of evaluating the prevalence, co-morbidity, functional impairment, physical morbidity, and social determinants of significant mental disorders in the population. This paper describes the background and design of the survey, and is the first territory-wide psychiatric epidemiological study in Hong Kong.

Patients with bipolar disorders share similar but attenuated prospective memory impairments with patients with schizophrenia.

BACKGROUND: Prospective memory (PM) refers to the ability to remember to carry out an intended action in the future. PM is consistently found to be impaired in individuals with schizophrenia. Bipolar disorder and schizophrenia may represent conditions along a continuum, and share similar neurocognitive and genetic architecture. This study aimed to compare the nature and extent of PM impairment in individuals with schizophrenia and bipolar disorder. METHOD: Participants were 38 out-patients with schizophrenia and 40 out-patients with bipolar disorder in an early psychosis intervention programme, and 37 healthy controls. Time-, event- and activity-based PMs were assessed using a dual-task laboratory paradigm. Self-reported PM performance was gauged using the Prospective and Retrospective Memory Questionnaire. Analysis of covariance (ANCOVA), with intelligence quotient (IQ) and education included as covariates, was used to examine group difference on various types of PM. Repeated measures of ANCOVA were used to examine the group × PM type interaction effect. Correspondence between laboratory and self-reported PM measures was examined using correlational analysis. RESULTS: The group × PM type interaction effect was not significant, but the main effect of group was significant. Patients with schizophrenia and patients with bipolar disorder both performed more poorly than healthy participants in PM. The two clinical groups did not significantly differ in PM. Laboratory and self-reported PM measures did not correlate significantly with each other. CONCLUSIONS: Patients with bipolar disorder shared a similar PM impairment with those with schizophrenia. Findings of this study extended the similarity in neurocognitive impairments between the two psychiatric disorders to PM.

Concurrent psychiatric disorders are associated with significantly poorer quality of life in patients with rheumatoid arthritis.

OBJECTIVES: To study the effect of concurrent psychiatric disorders on health-related quality of life (HRQOL) in patients with rheumatoid arthritis (RA). METHODS: Consecutive Chinese patients who fulfilled the American College of Rheumatology (ACR) criteria for RA were recruited and interviewed by a psychiatrist for psychiatric disorders using the Chinese Bilingual Structured Clinical Interview for DSM-IV Axis I Disorders, Patient version (CB-SCID-I/P). HRQOL was assessed by the validated Chinese version of the 36-item Short Form Health Survey (SF-36). Sociodemographic and clinical data were also collected. Fatigue was assessed by the Functional Assessment of Chronic Illness Therapy - Fatigue scale (FACIT-F). RESULTS: Two hundred patients with RA were studied (79% women, mean age 51.4 ± 10.5 years; median RA duration 4.0 years). Forty-seven (23.5%) patients were diagnosed with a psychiatric disorder: depressive disorders in 29 patients and anxiety disorders in 26 patients. Patients with either condition had significantly higher fatigue scores (26 ± 8.8 vs. 16 ± 6.9, p < 0.001) and were more likely to be unemployed (p = 0.02) and dependent on government subsidy for living (p < 0.001) than those without. The scores of the eight domains and the physical and mental components of the SF-36 were significantly lower in RA patients with psychiatric disorders (p < 0.001 in all). In a linear regression model, the presence of either depressive or anxiety disorders (ß = -0.23, p < 0.001), older age (ß = -0.16, p = 0.006), self-perceived pain (ß = -0.25, p < 0.001) and fatigue (ß = -0.42, p < 0.001) were independently and inversely associated with the total SF-36 score after adjustment for disease activity and other sociodemographic variables. CONCLUSIONS: Concomitant depressive or anxiety disorders in RA patients are associated with significantly poorer HRQOL. Early identification and treatment of psychiatric disorders in RA patients are warranted.

A study of sensitivity of the sustained attention to response task in patients with schizophrenia.

The sustained attention to response task (SART), a measure of sustained attention created by Robertson, Manly, Andrade, Baddeley, and Yiend (1997), was administered to 51 patients with schizophrenia and 51 normal controls to provide information on the sensitivity of the measure in this clinical group. Patients with schizophrenia performed significantly worse than the normal controls in correct response, reaction time for correct response, and efficiency estimate of taking account of both the accuracy and speed of movement. Moreover, the patient group was more often correctly classified as defective on the basis of efficiency estimate than the normal controls. These data provide further evidence of the sensitivity of the SART to patients with schizophrenia.

Problem-solving ability in chronic schizophrenia. A comparison study of patients with traumatic brain injury.

We tested the hypothesis that patients with schizophrenia are more prone to impairment in planning and problem-solving as compared with normal controls and patients with traumatic brain injury (TBI) by administering the Tower of Hanoi (TOH) task. A total of one hundred and fifty-three participants (51 in each group) were recruited. The performance of the patient groups was markedly worse than normal controls in terms of profile score, number of rule-breaking behaviour, and mean execution time. Two-way 3 (group) x 6 (complexity) ANOVAs indicated that significant main effects of group and complexity were observed in the number of moves, planning time to initiate the first move and subsequent execution time. The general performance of TOH in the schizophrenia group was very similar to that of the TBI group. Subsequent comparison of sub-groups of frontal and posterior lobe damage indicated the pattern of performance in schizophrenia patients lie between them. Taken together, these findings suggest that neither focal frontal nor temporal lobe damage is a sufficient explanation for the problem-solving deficits in patients with schizophrenia.

Executive dysfunctions in schizophrenia. Relationships to clinical manifestation.

Studies suggest that executive functions in patients with schizophrenia are markedly impaired as compared with normal controls. Most previous studies employed tests of executive functions adopted from frontal lobe neuropsychological paradigms based on lesion studies. This study employed several more recently developed theory-driven tests of executive functions addressing the construct of the supervisory attentional system. We explore the pattern of executive function impairment using factor analysis and subsequently investigate the relationships between these executive function factors and the clinical features in a sample of chronic schizophrenic patients. A total of 51 patients with chronic schizophrenia were recruited. The Sustained Attention Response to Task (SART), Six Elements Test (SET) and Hayling Sentence Completion Test (HSC) were used to assess executive functions. Three factors were identified within the executive function tests: 1) The "semantic inhibition factor" comprised items in the HSC, 2) the "action/attention inhibition" factor comprised the SART commission error and the SET rule-breaking score and 3) the "output generation factor" comprised the SET raw score and the correct SART response. Significant relationships were found between these derived factors and clinical features after partialling out the confounding effect of age, education and illness duration. The three theory-based tests of executive function were shown to have good construct validity among the group of chronic schizophrenic patients.

No association between T102C polymorphism of serotonin-2A receptor gene and clinical phenotypes of Chinese schizophrenic patients.

Serotonin dysfunction has been implicated in the pathogenesis of schizophrenia. Previous studies have shown an association between the T102C polymorphism of the 5HT2a receptor gene and schizophrenia. However, negative findings have also been reported. One possible explanation for such discrepancy is disease heterogeneity due to the current limitations in the diagnosis of schizophrenia. We conducted a case-control study of the T102C polymorphism with detailed characterisation of the clinical phenotypes to investigate the possible association with schizophrenia not only at the diagnostic level, but also with reference to other clinical phenotypes potentially related to serotonin dysfunction. Four hundred and seventy-one biologically unrelated schizophrenic patients and 523 unrelated healthy controls of Han Chinese descent in Hong Kong were compared for genotypes and allele frequencies of the T102C polymorphism by PCR amplification and restriction analysis. No evidence of association was detected at the diagnostic level and various clinical phenotypes. However, we found a trend association with small effect size between genotype 102T/102C and patients with better verbal fluency and less motor co-ordination soft neurological signs. There is a need for future large-scale studies on the possible associations between genetic polymorphisms and neurocognitive function impairments in schizophrenia.