Latent structure of psychosis in the general population: results from the Singapore mental health study

Psychosis risk among pregnant women in Ghana

Introduction

Psychotic illness, although is rare, has been reported in the perinatal period. Individuals diagnosed with psychotic illness tend to first exhibit psychotic-like experiences (PLEs), defined as subclinical psychotic symptoms that occur outside the context of sleep or drug use. However, there is a paucity of empirical data on PLEs in pregnancy to advance scholarly discourse and support professional practice. The current study investigated the prevalence and correlates of PLEs among pregnant women in Ghana, a West African state.

Design

A cross-sectional survey design was used to collect data from 702 pregnant women who responded to measures of PLEs, COVID-19 concerns and behavioral maladies such as anxiety and depressive symptoms. Descriptive and inferential statistics, namely chi square, exploratory factor analysis, MANOVA and multinomial logistic regression were used to analyze the data.

Results

The results showed that 54.2%, 27.3% and 18.5% of participants were at no/low, moderate and high risk for psychosis, respectively. A total of 44.4% participants were not distressed by PLEs, whereas 32.2% and 23.4% were a bit/quite and very distressed, respectively. Psychosis risk was elevated among pregnant women who were more concerned about the COVID-19 effects, scored high in suicidal ideation, depressive symptoms and sleep difficulties.

Conclusion

The study showed that psychosis risk is present in pregnancy.

Implications

Screening for psychosis risk in pregnancy should be prioritized for pregnant women with behavioral maladies, including suicidal tendencies, depressive symptoms, sleep difficulties and heightened concerns about COVID-19.

Latent structure of psychotic-like experiences in adolescents: Evidence from a multi-method taxometric study of a school-based sample in Ghana

Psychotic-like experiences (PLEs) are subclinical psychotic symptoms that occur outside the context of sleep or are unrelated to drug use. PLEs of varying severity are reportedly very common in adolescence. However, there are concerns about whether the structure of PLEs among adolescents is latently dimensional or categorical ("taxonic"). The current study investigates the latent structure of PLEs in 1,886 adolescents recruited from senior high schools in Ghana. Four multivariate taxometric procedures (MAMBAC, MAXEIG, l-Mode and MAXSLOPE) were applied to analyze the data. Across the taxometric procedures, there was evidence that a dimensional structure underpins positive PLEs, negative PLEs and a combination of positive and negative PLEs. The findings suggest that PLEs are distributed in the adolescent population at differing degrees/severity and that evidence of discontinuity between milder and more severe PLEs is non-existent. The findings highlight the importance of incorporating a dimensional assessment of PLEs into the existing categorical approach so that differences between people can been seen as quantitative variations along the PLEs continuum.

Testing Measurement Invariance Across Unobserved Groups: The Role of Covariates in Factor Mixture Modeling

Factor mixture modeling (FMM) has been increasingly used to investigate unobserved population heterogeneity. This study examined the issue of covariate effects with FMM in the context of measurement invariance testing. Specifically, the impact of excluding and misspecifying covariate effects on measurement invariance testing and class enumeration was investigated via Monte Carlo simulations. Data were generated based on FMM models with (1) a zero covariate effect, (2) a covariate effect on the latent class variable, and (3) covariate effects on both the latent class variable and the factor. For each population model, different analysis models that excluded or misspecified covariate effects were fitted. Results highlighted the importance of including proper covariates in measurement invariance testing and evidenced the utility of a model comparison approach in searching for the correct specification of covariate effects and the level of measurement invariance. This approach was demonstrated using an empirical data set. Implications for methodological and applied research are discussed.

Maternal cerebellar gray matter volume is associated with daughters' psychotic experience

AIM

A substantial portion of children and adolescents show subthreshold psychotic symptoms called psychotic experience (PE). Because PE shares its biological and environmental risk factors with psychotic spectrum disorders, parental neuroanatomical variation could reflect a heritable biological underpinning of PE that may predict an offspring's PE.

METHODS

A total of 94 participants from 35 families without a diagnosis of major neuropsychiatric disorders were examined, including 14 mother-daughter, 17 mother-son, 12 father-daughter, and 16 father-son dyads. An offspring's PE was assessed with the Atypicality subscale of the Behavior Assessment System for Children - 2nd Edition, Self-Report of Personality form (BASCaty). We examined correlations between voxel-by-voxel parental gray matter volume and their offspring's BASCaty score.

RESULTS

Maternal cerebellar gray matter volume using voxel-based morphometry was positively correlated with their daughters' BASCaty scores. The findings were significant in a more robust approach using cerebellum-specific normalization known. We did not find significant correlation between paternal gray matter volume and BASCaty scores or between offspring gray matter volumes and their BASCaty scores.

CONCLUSION

Expanding upon parent-of-origin effects in psychosis, maternal neuroanatomical variation was associated with daughters' PE. The nature of this sex-specific intergenerational effect is unknown, but maternally transmitted genes may relate cerebellum development to PE pathogenesis.

Common Taxonomy of Traits and Symptoms: Linking Schizophrenia Symptoms, Schizotypy, and Normal Personality

The associations among normal personality and many mental disorders are well established, but it remains unclear whether and how symptoms of schizophrenia and schizotypal traits align with the personality taxonomy. This study examined the joint factor structure of normal personality, schizotypy, and schizophrenia symptoms in people with psychotic disorders (n = 288) and never-psychotic adults (n = 257) in the Suffolk County Mental Health Project. First, we evaluated the structure of schizotypal (positive schizotypy, negative schizotypy, and mistrust) and normal traits. In both the psychotic-disorder and never-psychotic groups, the best-fitting model had 5 factors: neuroticism, extraversion, conscientiousness, agreeableness, and psychoticism. The schizotypy traits were placed on different dimensions: negative schizotypy went on (low) extraversion, whereas positive schizotypy and mistrust went on psychoticism. Next, we added symptoms to the model. Numerous alternatives were compared, and the 5-factor model remained best-fitting. Reality distortion (hallucinations and delusions) and disorganization symptoms were placed on psychoticism, and negative symptoms were placed on extraversion. Models that separated symptom dimensions from trait dimensions did not fit well, arguing that taxonomies of symptoms and traits are aligned. This is the first study to show that symptoms of psychosis, schizotypy, and normal personality reflect the same underlying dimensions. Specifically, (low) extraversion, negative schizotypy, and negative symptoms form one spectrum, whereas psychoticism, positive schizotypy, and positive and disorganized symptoms form another. This framework helps to understand the heterogeneity of psychosis and comorbidity patterns found in psychotic disorders. It also underscores the importance of traits to understanding these disorders.

Evaluating DSM-5 Insomnia Disorder and the Treatment of Sleep Problems in a Psychiatric Population

STUDY OBJECTIVES

With the introduction of insomnia disorder in Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), greater emphasis has been placed on the diagnosis and treatment of sleep disorder even in the presence of a coexisting mental disorder. The current study seeks to explore the clinical picture of insomnia in the context of psychiatric disorders commonly associated with sleep complaints by assessing the prevalence and correlates of DSM-5 insomnia disorder, and examining the extent to which insomnia symptoms have been addressed in this population.

METHODS

Four hundred treatment-seeking outpatients suffering from depressive, bipolar affective, anxiety, and schizophrenia spectrum disorders were recruited. DSM-5 insomnia was established using the modified Brief Insomnia Questionnaire. Differences in sociodemographic factors, clinical status, impairment outcomes, and mental health services utilization were compared. Information on patients' help-seeking experiences for insomnia-related symptoms was collected to determine the treatment received and treatment effectiveness.

RESULTS

Almost one-third of our sample (31.8%) had DSM-5 insomnia disorder. Those with insomnia disorder had significantly higher impairment outcomes than their counterparts but no group difference was observed for mental health services utilization. Findings based on past treatment contact for sleep problems suggest that diagnosis and treatment of insomnia is lacking in this population.

CONCLUSIONS

With the new calling from DSM-5, clinicians treating psychiatric patients should view insomnia less as a symptom of their mental illnesses and treat clinical insomnia as a primary disorder. Patients should also be educated on the importance of reporting and treating their sleep complaints. Nonmedical (cognitive and behavioral) interventions for insomnia need to be further explored given their proven clinical effectiveness.

Poverty, low education, and the expression of psychotic-like experiences in the general population of São Paulo, Brazil

The aim of our study was to assess psychotic-like experiences in the general population aged 18-30 years old of the city of São Paulo, Brazil. A household survey was conducted with 1950 young-adults randomly drawn from the city's general population. The validated 92-item Portuguese version of the Prodromal Questionnaire (PQ) was used for face-to-face interviews. Latent class analysis was conducted. Mean age was of 24 years; 51.1% of the sample was of women. Mean total score on the PQ was 22.06 (SD=17.16). Considering a suggested cut-off of 14 in the positive subscale, 30.8% of individuals were above the threshold for ultra-high risk for psychosis detection. Latent class analysis resulted in a three classes clusterization. Class 1 (20%; n=390) had the highest overall PQ scores (mean=49.31,SD=10.783), class 2 (43%; n=835) had intermediate scores (mean=23.37,SD=6.56), and class 3 (37%; n=721) had the lowest scores (mean=5.81,SD=3.74). Class 1 had significantly more individuals with less education and significantly more individuals with lower socioeconomic class. Poverty and low education might be associated with the psychotic expression in the general population, amplifying their actions on the psychosis gradient in developing countries. The psychosis continuum might be constituted by three distinct quantitatively different classes.

Continuum beliefs and stigmatising beliefs about mental illness: results from an Asian community survey

OBJECTIVES

To establish the prevalence and correlates of continuum beliefs for five mental illnesses in a multiethnic population and to explore its association with stigma.

DESIGN

A community-based, cross-sectional study.

SETTING

A national study in a multiethnic Asian country.

PARTICIPANTS

A comprehensive study of 3006 Singapore residents (Singapore citizens and permanent residents) aged 18-65 years who were living in Singapore at the time of the survey.

OUTCOME MEASURES

Parameters assessed included belief in a continuum of symptom experience, stigma dimensions and causal beliefs in mental illness. Statistical analyses included descriptive statistics and multiple linear regression (MLR).

RESULTS

About half of the population indicated agreement with a continuum of symptoms for depression (57.9%) and dementia (46.8%), whereas only about one in three respondents agreed with it for alcohol abuse (35.6%), schizophrenia (32.7%) and obsessive-compulsive disorder (OCD) (36.8%). MLR analyses revealed that students (β=0.28; 95% CI 0.05 to 0.50; p=0.018) and those who were unemployed (β=0.60; 95% CI 0.26 to 0.95; p=0.001) (vs employed) as well as those who had previous contact with people with mental illness (β = 0.31; 95% CI 0.18 to 0.45; p<0.001) and believed stress, family arguments, difficulties at work or financial difficulties to be a cause for mental illness (β=0.43; 95% CI 0.13 to 0.73; p=0.005) were associated with a higher belief in a continuum of symptom experience. Continuum beliefs were related to lower desire for social distance in alcohol abuse, OCD and schizophrenia; however, they were associated with higher scores on 'weak-not-sick' stigma dimension in dementia and schizophrenia.

CONCLUSIONS

Perceiving that a person with a mental illness is similar to themselves may reduce social distancing by the public. Thus, the approach may lend itself well to public education aimed at reducing stigma.

Prevalence of psychotic symptoms among older adults in an Asian population

BACKGROUND

Psychotic symptoms are common among older adults and are seen in a wide range of conditions. Most studies examining the prevalence and correlates of psychotic symptoms among older adults have been conducted in Western populations. To address this gap the current study was undertaken to establish the prevalence and correlates of psychotic symptoms and paranoid ideation within a community sample of older adults without dementia in an Asian population.

METHODS

The Well-being of the Singapore Elderly (WiSE) study was a comprehensive single phase, cross-sectional survey. All respondents were assessed using the Geriatric Mental State examination (GMS). Specific questions of the GMS were then used to establish the prevalence of hallucinations and persecutory delusions.

RESULTS

A total of 2,565 respondents completed the study giving a response rate of 65.6%. The prevalence of any psychotic symptoms in this population of older adults was 5.2%. The odds of hallucinations and any psychotic symptoms were significantly higher among those of Malay ethnicity, and those who had no formal education. Older adults aged 75-84 years were significantly associated with lower odds of having hallucinations (vs. older adult aged 60-74 years), while homemaker status was significantly associated with lower odds of having any psychotic symptoms.

CONCLUSIONS

The prevalence of psychotic symptoms among older Asian adults without dementia was higher than that reported from Western countries. Psychotic symptoms were associated with Malay ethnicity, poor cognitive performance and fewer years of schooling, visual and hearing impairment as well as depression and irritability.

Adult psychotic symptoms, their associated risk factors and changes in prevalence in men and women over a decade in a poor rural district of Kenya

There have been no repeat surveys of psychotic symptoms in Kenya or indeed subSaharan Africa. A mental health epidemiological survey was therefore conducted in a demographic surveillance site of a Kenyan household population in 2013 to test the hypothesis that the prevalence of psychotic symptoms would be similar to that found in an earlier sample drawn from the same sample frame in 2004, using the same overall methodology and instruments. This 2013 study found that the prevalence of one or more psychotic symptoms was 13.9% with one or more symptoms and 3.8% with two or more symptoms, while the 2004 study had found that the prevalence of single psychotic symptoms in rural Kenya was 8% of the adult population, but only 0.6% had two symptoms and none had three or more psychotic symptoms. This change was accounted for by a striking increase in psychotic symptoms in women (17.8% in 2013 compared with 6.9% in 2004, p < 0.001), whereas there was no significant change in men (10.6% in 2013 compared with 9.4% in 2004, p = 0.582). Potential reasons for this increase in rate of psychotic symptoms in women are explored.

Factors of psychological distress: clinical value, measurement substance, and methodological artefacts

PURPOSE

Psychometric models and statistical techniques are cornerstones of research into latent structures of specific psychopathology and general mental health. We discuss "pivot points" for future research efforts from a psychometric epidemiology perspective, emphasising sampling and selection processes of both indicators that guide data collection as well as samples that are confronted with them.

METHOD

First, we discuss how a theoretical model of psychopathology determines which empirical indicators (questions, diagnoses, etc.) and modelling methods are appropriate to test its implications. Second, we deal with how different research designs introduce different (co-)variances between indicators, potentially leading to a different understanding of latent structures. Third, we discuss widening the range of statistical models available within the "psychometrics class": the inclusion of categorical approaches can help to enlighten the debate on the structure of psychopathology and agreement on a minimal set of models might lead to greater convergence between studies. Fourth, we deal with aspects of methodology that introduce spurious (co-)variance in latent structure analysis (response styles, clustered data) and differential item functioning to gather more detailed information and to guard against over-generalisation of results, which renders assessments unfair.

CONCLUSIONS

Building on established insights, future research efforts should be more explicit about their theoretical understanding of psychopathology and how the analysis of a given indicator-respondent set informs this theoretical model. A coherent treatment of theoretical assumptions, indicators, and samples holds the key to building a comprehensive account of the latent structures of different types of psychopathology and mental health in general.