The 12-month prevalence of psychotic experiences and their association with clinical outcomes in Hong Kong: an epidemiological and a 2-year follow up studies

BACKGROUND

The relationship between the subtypes of psychotic experiences (PEs) and common mental health symptoms remains unclear. The current study aims to establish the 12-month prevalence of PEs in a representative sample of community-dwelling Chinese population in Hong Kong and explore the relationship of types of PEs and common mental health symptoms.

METHOD

This is a population-based two-phase household survey of Chinese population in Hong Kong aged 16-75 (N = 5719) conducted between 2010 and 2013 and a 2-year follow-up study of PEs positive subjects (N = 152). PEs were measured with Psychosis Screening Questionnaire (PSQ) and subjects who endorsed any item on the PSQ without a clinical diagnosis of psychotic disorder were considered as PE-positive. Types of PEs were characterized using a number of PEs (single v. multiple) and latent class analysis. All PE-positive subjects were assessed with common mental health symptoms and suicidal ideations at baseline and 2-year follow-up. PE status was also assessed at 2-year follow-up.

RESULTS

The 12-month prevalence of PEs in Hong Kong was 2.7% with 21.1% had multiple PEs. Three latent classes of PEs were identified: hallucination, paranoia and mixed. Multiple PEs and hallucination latent class of PEs were associated with higher levels of common mental health symptoms. PE persistent rate at 2-year follow-up was 15.1%. Multiple PEs was associated with poorer mental health at 2-year follow-up.

CONCLUSIONS

Results highlighted the transient and heterogeneous nature of PEs, and that multiple PEs and hallucination subtype of PEs may be specific indices of poorer common mental health.

The role of symptoms and insight in mediating cognition and functioning in first episode psychosis

INTRODUCTION

Achieving functional recovery in patients with psychosis is a challenge in clinical practice. Investigating the complex interplay between cognition, symptoms, insight and functional outcome in first episode psychosis will be crucial to understanding the factors leading to better functioning.

METHODS

In this 12-month prospective follow-up study, we investigated how cognition, clinical symptoms, and insight into illness affected overall functioning in 160 patients with first episode psychosis recruited from the Early Assessment Service for Young People with Psychosis (EASY) in Hong Kong from July 1, 2014 to June 30, 2016. Cognition was assessed at baseline while symptoms, insight, and functioning were assessed at 12-month follow-up. Structural equation modelling was used to examine the direct and indirect relationships between functioning and other latent constructs.

RESULTS

Symptoms (negative symptoms and general psychopathology) and insight were shown to be significant mediators between cognition and functioning. The significant direct relationship between cognition and functioning (β = 0.387; p < 0.001) became insignificant (β = 0.079; p = 0.578) after including symptoms and insight in the model. Symptoms and insight were significantly associated with cognition (symptoms, β = -0.469; p < 0.001; insight, β = -0.372; p < 0.001) and predicted functioning (symptoms, β = -0.558; p < 0.001; insight, β = -0.264; p < 0.01).

CONCLUSION

Symptoms and insight mediated the effects of cognition on functioning. Interventions for improving functioning in patients with first episode psychosis should target not only cognition but also symptoms and insight.

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.

Lifetime Prevalence and Correlates of Schizophrenia-Spectrum, Affective, and Other Non-affective Psychotic Disorders in the Chinese Adult Population

Lifetime prevalence of psychotic disorders varies widely across studies. Epidemiological surveys have rarely examined prevalences of specific psychotic disorders other than schizophrenia, and the majority used a single-phase design without employing clinical reappraisal interview for diagnostic verification. The current study investigated lifetime prevalence, correlates and service utilization of schizophrenia-spectrum, affective, and other non-affective psychotic disorders in a representative sample of community-dwelling Chinese adult population aged 16-75 years (N = 5719) based on a territory-wide, population-based household survey for mental disorders in Hong Kong. The survey adopted a 2-phase design comprising first-phase psychosis screening and second-phase diagnostic verification incorporating clinical information from psychiatrist-administered semi-structured interview and medical record review to ascertain DSM-IV lifetime diagnosis for psychotic disorders. Data on sociodemographics, psychosocial characteristics and service utilization were collected. Our results showed that lifetime prevalence was 2.47% for psychotic disorder overall, 1.25% for schizophrenia, 0.15% for delusional disorder, 0.38% for psychotic disorder not otherwise specified, 0.31% for bipolar disorder with psychosis, and 0.33% for depressive disorder with psychosis. Schizophrenia-spectrum disorder was associated with family history of psychosis, cigarette smoking and variables indicating socioeconomic disadvantage. Victimization experiences were significantly related to affective psychoses and other non-affective psychoses. Around 80% of participants with any psychotic disorder sought some kind of professional help for mental health problems in the past year. Using comprehensive diagnostic assessment involving interview and record data, our results indicate that approximately 2.5% of Chinese adult population had lifetime psychotic disorder which represents a major public health concern.

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.

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.

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.

Prevalence and determinants of psychiatric disorders in patients with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is the most common chronic rheumatological disorder among southern Chinese patients in Hong Kong, with an estimated prevalence of 0.33%-0.35%. The resulting chronic pain, disability, social stress, and isolation contribute to the development of psychiatric symptoms.

OBJECTIVE

The authors identify the prevalence and determining factors of psychiatric disorders in patients with RA.

METHOD

Consecutive RA patients (N=200) were recruited from a rheumatology outpatient clinic. Psychiatric disorders were diagnosed by a psychiatrist using the Chinese-bilingual Structured Clinical Interview for DSM-IV Axis I disorders, Patient Research Version. Sociodemographic and clinical data and subjective health status and perceived social support data were also collected. Factors associated with the occurrence of psychiatric disorders were studied by multivariate analysis.

RESULTS

A total of 47 patients were diagnosed with a current psychiatric disorder (depressive disorders, 14.5%; anxiety disorders, 13.0%; schizophrenia, 0.5%). Major depressive disorder and generalized anxiety disorder were the commonest current mood and anxiety disorders, respectively. Independent predictors for a current psychiatric disorder were poverty and perceived poor social support. Limited social interaction, perceived poor social support, high pain intensity, and a family history of psychiatric disorders were independently associated with a current depressive disorder, whereas poverty and perceived poor social support were associated with a current anxiety disorder.

CONCLUSION

Depression and anxiety are common in Chinese patients with RA. Patients who lack social support or rely on economic assistance are more prone to the development of psychiatric disorders.

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.

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.

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.