Association of Urbanicity with Schizophrenia and Related Mortality in China: Association de l'urbanicité avec la schizophrénie et la mortalité qui y est reliée en Chine

The association between area-level factors and mortality in severe mental illnesses: A systematic review

BACKGROUND

Premature mortality is a well-documented adverse outcome for people living with severe mental illnesses (SMI). Emerging evidence suggests that area-level factors play a role that are experienced disproportionately by this population. This review assesses the potential association between area-level factors and mortality in people with SMI.

METHOD

We searched Medline, EMBASE, PsychINFO, Social Policy and Practice, Web of Science and OpenGrey databases. Literature searches were conducted in May 2020 and updated in June 2023. Reference lists were hand-searched and authors of included studies contacted to identify additional studies and minimise publication biases. Narrative synthesis was used to appraise the included studies. The review protocol was registered on PROSPERO (CRD42019155447).

RESULTS

Our searches identified 7 studies (8 papers), which were included in the review, and indicated evidence of an association between deprivation and mortality. One study suggested an association between mortality in SMI and urbanicity in low to middle income settings which was not observed in studies from high income settings. One study suggested a protective association of area-level ethnic density with mortality within urbanised settings.

CONCLUSION

Consistent associations were reported between residence in areas of higher deprivation and increased risk of mortality in SMI. Two studies suggested an association between area-level ethnic density and urbanicity and mortality in SMI. Most studies were conducted across high income countries and therefore future research could benefit from similar investigations being conducted in low- and middle-income countries. These methods would inform health and social policies, including interventions to reduce premature mortality in SMI.

Incidence, prevalence, and mortality of schizophrenia from 2016 to 2020 in Shandong, China

The epidemiology of schizophrenia has been reported in many countries. However, due to the limitations of those studies, the findings cannot be generalized to other parts of the world, especially in China. In this study, the incidence, prevalence, and mortality of schizophrenia in Shandong, China were calculated using data from the National Severe Mental Disorder Registration System collected between 2016 and 2020 and census data from 2010 to 2020. The overall incidence decreased from 9.61 per 100,000 in 2016 to 4.40 per 100,000 in 2020, the aggregate prevalence was approximately 3.20 per 1000, and the overall mortality ranged from 6.17 per 100,000 to 7.71 per 100,000. The evidence from this study indicated that the incidence, prevalence, and mortality of schizophrenia were higher in rural areas than in urban areas. Females had higher incidence, prevalence, and mortality than males. This study provided epidemiological information on schizophrenia and opened avenues for future research.

Schizophrenia: A Review of Social Risk Factors That Affect Women

Social risk factors are long-term or repeated environmental exposures in childhood and youth that change the brain and may, via epigenetic effects, change gene expression. They thus have the power to initiate or aggravate mental disorders. Because these effects can be mediated via hormonal or immune/inflammatory pathways that differ between men and women, their influence is often sex-specific. The goal of this narrative review is to explore the literature on social risk factors as they affect women with schizophrenia. We searched the PubMed and Scopus databases from 2000 to May 2023 using terms referring to the various social determinants of health in conjunction with "women" and with "schizophrenia". A total of 57 studies fulfilled the inclusion criteria. In the domains of childhood and adult abuse or trauma, victimization, stigma, housing, and socioeconomics, women with schizophrenia showed greater probability than their male peers of suffering negative consequences. Interventions targeting appropriate housing, income support, social and parenting support, protection from abuse, violence, and mothering-directed stigma have, to different degrees, yielded success in reducing stress levels and alleviating the many burdens of schizophrenia in women.

Suicidality and Its Association with Stigma in Clinically Stable Patients with Schizophrenia in Rural China

Purpose

Patients with schizophrenia not only experience more stigma than those with other mental illnesses, but they also have a higher risk of committing suicide. There are, however, few research on the connection between rural individuals with clinically stable schizophrenia and suicidality when they feel stigmatized. Therefore, the purpose of this study was to look at the suicidality in clinically stable patients with schizophrenia in rural China, including the prevalence, clinical correlates, and its relationships with stigma.

Patients and Methods

From September 2022 to October 2022, we conducted a multicenter, cross-sectional study in rural Chaohu, Anhui Province, China, and A total of 821 patients with schizophrenia completed the assessment. Three standardized questions were used to assess suicidality (including suicidal ideation, suicide plan, and suicide attempt), Patient Health Questionnaire with 9 items (PHQ-9) for determining depressive state, the first two items of the World Health Organization Quality of Life Questionnaire-Brief Version (QOL), which measures quality of life, the Social Impact Scale (SIS) to assess stigma, and some other important variables (eg employment, psychiatric medication, etc.) were measured using a homemade scale.

Results

Of the 821 participants who completed the questionnaire, 19.2% of the patients were found to have suicidality, of which 19.2% (158/821) were suicidal ideation, 5.6% (46/821) were suicide plans and 4.5% (37/821) were suicide attempts. Binary logistic regression analysis showed that job status (OR=0.520, p=0.047), psychiatric medication (OR=2.353, p=0.020), number of hospitalizations (OR=1.047, p=0.042), quality of life (OR=0.829, p=0.027), PHQ-9 (OR=0.209, p<0.001) stigma (OR=1.060, p<0.001) and social isolation in stigma (OR=1.134, p=0.001) were associated independently with suicidality.

Conclusion

Among clinically stable schizophrenia patients in rural China, suicidality is frequent and associated with stigma. Since stigma and some risk factors have a negative impact on suicidality, we should conduct routine screening and take suicide prevention measures to clinically stable schizophrenia patients in rural areas of China.

Trends and burden in mental disorder death in China from 2009 to 2019: a nationwide longitudinal study

Objectives

We aimed to elucidate trends in the crude mortality rate (CMR), age-standardized mortality rate (ASMR), and burden of mental disorders (MD) in China.

Methods

A longitudinal observational study was performed using the data of MD deaths in the National Disease Surveillance System (DSPs) during 2009-2019. The mortality rates were normalized using the Segis global population. Trends in the mortality of MDs stratified by age, gender, region, and residency, respectively. The burden of MD was evaluated using age-standardized person years of life loss per 100,000 people (SPYLLs) and average years of life lost (AYLL).

Result

A total of 18,178 MD deaths occurred during 2009-2019, accounting for 0.13% of total deaths, and 68.3% of MD deaths occurred in rural areas. The CMR of MD in China was 0.75/100,00 persons (ASMR: 0.62/100,000 persons). The ASMR of all MDs decreased mainly due to the decrease in ASMR in rural residents. Schizophrenia and alcohol use disorder (AUD) were the leading causes of death in MD patients. The ASMR of schizophrenia and AUD was higher in rural residents than in urban residents. The ASMR of MD was highest in the 40-64 age group. As the leading causes of MD burden, the SPYLL and AYLL of schizophrenia were 7.76 person-years and 22.30 years, respectively.

Conclusion

Although the ASMR of all MDs decreased during 2009-2019, schizophrenia and AUD were still the most important causes of death for MDs. Targeted efforts focusing on men, rural residents, and the 40-64 years old population should be strengthened to decrease MD-related premature deaths.

Sunshine duration and risks of schizophrenia hospitalizations in main urban area: Do built environments modify the association?

BACKGROUND

Although studies have explored the relationship between sunshine duration and schizophrenia, the evidence was ambiguous. Different built environments may alter the effect of sunlight on schizophrenia, thus the purpose of this study was to investigate the effects of built environments on the sunshine duration-schizophrenia association.

MATERIALS AND METHODS

Daily schizophrenia hospitalizations data during 2017-2020 in Hefei's main urban area, China, and corresponding meteorological factors as well as ambient pollutants were collected. The impact of sunshine duration on schizophrenia admissions in urban areas was investigated using a generalized additive model combined with a distributed lagged nonlinear model. Additionally, the various modifying effects of different Building Density, Building Height, Normalized Vegetation Index, and Nighttime Light were also explored between sunshine duration and schizophrenia.

RESULTS

We observed that inadequate sunshine duration (<5.3 h) was associated with an increase in schizophrenia hospital admissions, with a maximum relative risk of 1.382 (95 % confidence interval (CI): 1.069-1.786) at 2.9 h. In turn, adequate sunshine duration reduced the risk of schizophrenia hospitalizations. Subgroup analyses indicated females and old patients were particularly vulnerable. In the case of insufficient sunshine duration, significant positive effects were noticed on schizophrenia risk at High-Building Density and High-Nighttime Light. Higher NDVI as well as Building Height were found to be associated with lower risks of schizophrenia.

CONCLUSIONS

Given that sunshine duration in various built environments might lead to distinct effects on schizophrenia hospitalizations. Our findings assist in identifying vulnerable populations that reside in particular areas, thus suggesting policymakers provide advice to mitigate the onset of schizophrenia by allocating healthcare resources rationally and avoiding adverse exposures to vulnerable populations timely.

Gender differences in association of urbanization with psychological stress in Chinese adults: A population-based study

Objective

To investigate the gender-specific associations between exposure to urbanization and psychological stress in China experiencing rapid urbanization.

Methods

Data were obtained from the 2015 China Health and Nutrition Survey. A total of 4,388 men and 5,098 women aged at least 18 years were obtained from 288 communities across 12 provinces and municipalities. Tertiles of the urbanization index, summarizing 12 urbanization dimensions at the community level, were used to define low, medium, and high levels of urbanization. The psychological stress was measured based on the 10-item Perceived Stress Scale. The gender-stratified multilevel analysis (Level-1: Individuals, Level-2: Communities, and Level-3: provinces/municipalities) was used to estimate the association between exposure to urbanization and psychological stress.

Results

After controlling for age, education status, marital status, work status, household income per capita, current smoking, alcohol drinking, sleep duration, BMI, and chronic conditions, the urbanization index was negatively associated with psychological stress in women (P _trend = 0.017) but not men (P _trend = 0.476). More specifically, a one-standard deviation increase in the score of community population density (β = -0.329, P = 0.329), modern markets (β = -0.247, P = 0.044), education (β = -0.448, P = 0.002), and housing (β = -0.380, P = 0.005) was negatively associated with psychological stress only in women, separately.

Conclusion

Our data revealed that living in the most urbanized communities is associated with lower levels of psychological stress for women but not men. Thus, this study can help empower decision-makers to accurately target vulnerable communities and plan effective strategies to address psychological outcomes.

Associations between urban birth or childhood trauma and first-episode schizophrenia mediated by low IQ

Exposure to urban birth, childhood trauma, and lower Intelligence Quotient (IQ) were the most well-established risk factors for schizophrenia in developed countries. In developing countries, whether urban birth is a risk factor for schizophrenia and how these factors are related to one another remain unclear. This study aimed to investigate whether IQ mediates the relationship between urban birth or childhood trauma and first-episode schizophrenia (FES) in China. Birthplace, childhood trauma questionnaire (CTQ), and IQ were collected from 144 patients with FES and 256 healthy controls (HCs). Hierarchical logistic regression analysis was conducted to investigate the associations between birthplace, childhood trauma, IQ, and FES. Furthermore, mediation analysis was used to explore the mediation of IQ in the relationship between birthplace or childhood trauma and FES. After adjusting for age, sex and educational attainment, the final model identified urban birth (odds ratio (OR) = 3.15, 95% CI = 1.54, 6.44) and childhood trauma (OR = 2.79, 95% CI = 1.92, 4.06) were associated an elevated risk for FES. The 52.94% total effect of birthplace on the risk of FES could be offset by IQ (indirect effect/direct effect). The association between childhood trauma and FES could be partly explained by IQ (22.5%). In total, the mediation model explained 70.5% of the total variance in FES. Our study provides evidence that urban birth and childhood trauma are associated with an increased risk of FES. Furthermore, IQ mediates the relationship between urban birth or childhood trauma and FES.

Mortality in people with schizophrenia: a systematic review and meta-analysis of relative risk and aggravating or attenuating factors

People with schizophrenia die 15-20 years prematurely. Understanding mortality risk and aggravating/attenuating factors is essential to reduce this gap. We conducted a systematic review and random-effects meta-analysis of prospective and retrospective, nationwide and targeted cohort studies assessing mortality risk in people with schizophrenia versus the general population or groups matched for physical comorbidities or groups with different psychiatric disorders, also assessing moderators. Primary outcome was all-cause mortality risk ratio (RR); key secondary outcomes were mortality due to suicide and natural causes. Other secondary outcomes included any other specific-cause mortality. Publication bias, subgroup and meta-regression analyses, and quality assessment (Newcastle-Ottawa Scale) were conducted. Across 135 studies spanning from 1957 to 2021 (schizophrenia: N=4,536,447; general population controls: N=1,115,600,059; other psychiatric illness controls: N=3,827,955), all-cause mortality was increased in people with schizophrenia versus any non-schizophrenia control group (RR=2.52, 95% CI: 2.38-2.68, n=79), with the largest risk in first-episode (RR=7.43, 95% CI: 4.02-13.75, n=2) and incident (i.e., earlier-phase) schizophrenia (RR=3.52, 95% CI: 3.09-4.00, n=7) versus the general population. Specific-cause mortality was highest for suicide or injury-poisoning or undetermined non-natural cause (RR=9.76-8.42), followed by pneumonia among natural causes (RR=7.00, 95% CI: 6.79-7.23), decreasing through infectious or endocrine or respiratory or urogenital or diabetes causes (RR=3 to 4), to alcohol or gastrointestinal or renal or nervous system or cardio-cerebrovascular or all natural causes (RR=2 to 3), and liver or cerebrovascular, or breast or colon or pancreas or any cancer causes (RR=1.33 to 1.96). All-cause mortality increased slightly but significantly with median study year (beta=0.0009, 95% CI: 0.001-0.02, p=0.02). Individuals with schizophrenia <40 years of age had increased all-cause and suicide-related mortality compared to those ≥40 years old, and a higher percentage of females increased suicide-related mortality risk in incident schizophrenia samples. All-cause mortality was higher in incident than prevalent schizophrenia (RR=3.52 vs. 2.86, p=0.009). Comorbid substance use disorder increased all-cause mortality (RR=1.62, 95% CI: 1.47-1.80, n=3). Antipsychotics were protective against all-cause mortality versus no antipsychotic use (RR=0.71, 95% CI: 0.59-0.84, n=11), with largest effects for second-generation long-acting injectable anti-psychotics (SGA-LAIs) (RR=0.39, 95% CI: 0.27-0.56, n=3), clozapine (RR=0.43, 95% CI: 0.34-0.55, n=3), any LAI (RR=0.47, 95% CI: 0.39-0.58, n=2), and any SGA (RR=0.53, 95% CI: 0.44-0.63, n=4). Antipsychotics were also protective against natural cause-related mortality, yet first-generation antipsychotics (FGAs) were associated with increased mortality due to suicide and natural cause in incident schizophrenia. Higher study quality and number of variables used to adjust the analyses moderated larger natural-cause mortality risk, and more recent study year moderated larger protective effects of antipsychotics. These results indicate that the excess mortality in schizophrenia is associated with several modifiable factors. Targeting comorbid substance abuse, long-term maintenance antipsychotic treatment and appropriate/earlier use of SGA-LAIs and clozapine could reduce this mortality gap.

Effects of extreme precipitation on hospitalization risk and disease burden of schizophrenia in urban and rural Lu'an, China, from 2010 to 2019

With the increasing frequency of extreme events caused by global climate change, the association between extreme precipitation (EP) and disease has aroused concern currently. However, no study has examined the relationship between EP and schizophrenia. Our study aimed to explore the relationship between EP and schizophrenia, and to further examine the difference between urban and rural areas. This study used quasi-Poisson generalized linear regression model combined with distributed lag non-linear model (DLNM) to estimate the association between EP (≥ 95th percentile) and hospitalization for schizophrenia from 2010 to 2019 in the city of Lu'an, China. EP could significantly increase the risk of hospitalization for schizophrenia. The effect firstly appeared at lag1 [relative risk (RR): 1.056, 95% confidence interval (95%CI): 1.003-1.110] and continued until lag17 (RR: 1.039, 95%CI: 1.004-1.075). Our research showed that EP had a significant effect on the hospitalization for schizophrenia in both urban and rural areas, and no significant difference was found (p>0.05). EP exerted more acute effects on schizophrenia living in rural areas than those in urban areas in the cold season. Further studies on the burden of schizophrenia found that patients who are male, aged ≤ 39 years or less, and living in urban areas are a priority for future warnings. We should pay more attention to the impact of EP on burden of schizophrenia, especially during the cold season, targeting those vulnerable groups, thereby implementing more accurate and timely preventive measures.

Temporal Trends in the Incidence and Disability Adjusted Life Years of Schizophrenia in China Over 30 Years

BACKGROUND

Schizophrenia is an important public health problem in China. This study aims to assess the long-term trends in the incidence and disability-adjusted life years (DALYs) rate of schizophrenia in China between 1990 and 2019.

METHODS

The incidence and DALYs data were drawn from the Global Burden of Disease Study 2019, and an age-period-cohort model was used in the analysis.

RESULTS

The age-standardized incidence rate (ASIR) and age-standardized DALYs rate (ASDR) of schizophrenia increased by 0.3 and 3.7% for both sexes between 1990 and 2019. For males, the local drift for incidence was higher than 0 (P < 0.05) in those aged 10 to 29 years (local drifts, 0.01 to 0.26%) and lower than 0 (P < 0.05) in those aged 35 to 74 years (local drifts, -1.01 to -0.06%). For females, the local drift was higher than 0 (P < 0.05) in those aged 10 to 34 years (local drifts, 0.05 to 0.26%) and lower than 0 (P < 0.05) in those aged 40 to 74 years (local drifts, -0.86 to -0.11%). The local drift for DALYs rate was higher than 0 (P < 0.05) in the age group from 10 to 69 years (local drifts, 0.06 to 0.26% for males and 0.06 to 0.28% for females). The estimated period and cohort relative risks (RR) for DALYs rate of schizophrenia were found in monotonic upward patterns, and the cohort RR for the incidence increased as the birth cohort moved forward starting with those born in 1972.

CONCLUSION

Although the crude incidence of schizophrenia has decreased in China, the ASIR, ASDR, and crude DALYs rate all showed a general increasing trend over the last three decades. The DALYs rate continue to increase as the birth cohort moved forward, and the increasing trend of incidence was also found in individuals born after 1972. More efforts are needed to promote mental health in China.