Cognitive impairment is a growing problem with increasing burden in ageing global population. Older adults with major depressive disorder (MDD) have higher risk of dementia during ageing. Neurofilament light chain (NfL) has been proven as a potential biomarker related to dementia. The present study aims to assess the cognitive deficits in older adults with MDD and investigate their association with peripheral blood levels of NfL.

We enrolled 39 individuals with MDD and 15 individuals with mild neurocognitive disorder or major neurocognitive disorder, Alzheimer’s type. Both groups were over age 65 and with restricted Mini-Mental State Examination (MMSE) score. Demographic data, clinical variables, and plasma NfL levels were obtained. We used cluster analysis according to their cognitive profile and estimated the correlation between plasma NfL levels and cognitive impairment in each domain.

In the MDD group, participants have higher rate of family psychiatry history and higher rate of current alcohol use habit compared with patients with neurocognitive disorders. In the neurocognitive disorders group, participants showed significantly lower score in total MMSE and higher plasma NfL levels. Part of the MDD patients presented cognitive deficits similar to that of neurocognitive disorders (cluster A). In cluster A, the total MMSE score (r=-0.58277, p=0.0287) and the comprehension domain (r=-0.71717, p=0.0039) were negatively correlated to NfL levels after adjusting for age, while the associations had not been observed in the other cluster.

We noted the negative correlation between NfL levels and cognitive performance in MDD patients whose cognitive manifestation were more similar to that of degenerative neurocognitive disorders. NfL might be a potential marker to predict patients with MDD to develop cognitive decline especially in domains typically found in Alzheimer’s disease. Further longitudinal studies are required to validate our findings for clinical implications.

We explored long-term employment status and income before and after depression diagnosis among men and women and at different working ages in Taiwan.

Data from 2006 to 2019 were obtained from the National Health Insurance Research Database (NHIRD). Individuals with newly diagnosed depressive disorder aged 15 to 64 years during the study period were identified. An equal number of individuals without depression were matched for their demographic and clinical characteristics. Employment outcomes included employment status, which was categorized into employed or unemployed, and annual income. Based on the occupation categories and monthly insurance salary recorded in the Registry for Beneficiaries of the NHIRD, a subject was defined as unemployed if he or she differed from the income earner or the occupation category was unemployed. Monthly income was defined as zero for unemployed subjects and proxied as monthly insurance salary for others. Annual income was the sum of monthly income in each observation year.

A total of 420,935 individuals with depressive disorder were included in the study, and an equal number of individuals with not diagnosed depression served as controls. Employment rate and income were lower in the depression group than in the control group before the year of diagnosis, with a difference of 5.7% in employment rate and USD 1,173 in annual income. This gap increased considerably after the year of diagnosis (7.3% in employment rate and USD 1,573 in annual incomes) and further widened in the subsequent years (8.1% in employment rate and USD 2,006 in annual incomes in the 5th following year). The drops in the employment rate and income caused by depression were more evident in men and older age groups than in women and younger age groups, respectively. However, the reduction in employment rate and income in the following years after the diagnosis was more considerable among younger age groups.

The effect of depression on employment status and income was significant during the year of diagnosis and continued afterwards. The effect on employment outcomes varied between genders and across all age groups.

Evidence suggests a familial coaggregation of major psychiatric disorders, including schizophrenia, bipolar disorder, major depression (MDD), autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD). Those disorders are further related to suicide and accidental death. However, whether death by suicide may coaggregate with accidental death and major psychiatric disorders within families remains unclear.

To clarify the familial coaggregation of deaths by suicide with accidental death and five major psychiatric disorders.

Using a database linked to the entire Taiwanese population, 68 214 first-degree relatives of individuals who died by suicide between 2003 and 2017 and 272 856 age- and gender-matched controls were assessed for the risks of death by suicide, accidental death and major psychiatric disorders.

A Poisson regression model showed that the first-degree relatives of individuals who died by suicide were more likely to die by suicide (relative risk RR = 4.61, 95% CI 4.02–5.29) or accident (RR = 1.62, 95% CI 1.43–1.84) or to be diagnosed with schizophrenia (RR = 1.53, 95% CI 1.40–1.66), bipolar disorder (RR = 1.99, 95% CI 1.83–2.16), MDD (RR = 1.98, 95% CI 1.89–2.08) or ADHD (RR = 1.34, 95% CI 1.24–1.44).

Our findings identified a familial coaggregation of death by suicide with accidental death, schizophrenia, major affective disorders and ADHD. Further studies would be required to elucidate the pathological mechanisms underlying this coaggregation.

Bipolar disorder is a chronic mental disorder related to cognitive deficits. Low serum vitamin D levels are significantly associated with compromised cognition in neuropsychiatric disorders. Although patients with bipolar disorder frequently exhibit hypovitaminosis D, the association between vitamin D and cognition in bipolar disorder, and their neuroaxonal integrity, is unclear.

To investigate the interaction effects between vitamin D and neurofilament light chain (NfL) levels on cognitive domains in bipolar disorder.

Serum vitamin D and NfL levels were determined in 100 euthymic patients with bipolar disorder in a cross-sectional study. Cognitive function was measured with the Brief Assessment of Cognition in Affective Disorders. We stratified by age groups and used general linear models to identify associations between vitamin D and NfL levels and their interaction effects on cognitive domains.

The mean vitamin D and NfL levels were 16.46 ng/nL and 11.10 pg/mL, respectively; 72% of patients were vitamin D deficient. In the older group, more frequent hospital admissions and lower physical activity were identified in the group with versus without vitamin D deficiency. The age-modified interaction effect of vitamin D and NfL was associated with composite neurocognitive scores and verbal fluency in both age groups, and with processing speed domain in the younger group.

We observed a high vitamin D deficiency prevalence in bipolar disorder. We identified the interaction of vitamin D and NfL on cognitive domains, and the effect was modified by age. Longitudinal or randomised controlled studies enrolling patients with various illness durations and mood statuses are required to validate our findings.

To investigate potential risk factors for mild behavioral impairment (MBI) among non-demented geriatrics.

Population-based, cross-sectional survey.

Taiwan Alzheimer Disease Association (TADA) Database.

Participants were selected by multistage random sampling of all Taiwan counties. They received in-person interviews between December 2011 and March 2013.

Demographic data, lifestyle and habits, medical comorbidities, cognitive status measured by the Taiwanese Mini-Mental Status Examination (TMSE) and presence of MCI of the participants were collected. Subjects were distributed to the MBI and non-MBI groups. These factors had been evaluated for their effects on MBI in the univariate and multivariable logistic regression models.

In total, 6,196 non-demented participants aged 65 years or older, including 409 MBI and 5,787 non-MBI participants, were recruited. After adjustment for age, sex, education, body mass index, lifestyle and habits, medical comorbidities, and MCI, good sleep was associated with lower risk of MBI (OR 0.09, 95% CI 0.07 – 0.12). Low body weight (OR 2.01, 95% CI 1.21–3.33), low-to-medium education (OR 1.40, 95%CI 1.06–1.85; OR 2.32, 95% CI 1.67–3.21), medical comorbidities of hypertension (OR 1.56, 95% CI 1.25–1.95), hyperlipidemia (OR 1.29, 95% CI 1.00–1.67), cancer (OR 2.05, 95% CI 1.37–3.06) were significantly associated with increased MBI risk. MCI neither increased nor decreased risk of MBI (OR 1.00, 95% CI 0.76–1.32).

Good sleep was associated with lower MBI risk. Underweight, lower education, medical comorbidities of cancer, hypertension, hyperlipidemia were predictive of MBI.

The impact of baseline hypertension status on the BMI–mortality association is still unclear. We aimed to examine the moderation effect of hypertension on the BMI–mortality association using a rural Chinese cohort.

In this cohort study, we investigated the incident of mortality according to different BMI categories by hypertension status.

Longitudinal population-based cohort.

17 262 adults ≥18 years were recruited from July to August of 2013 and July to August of 2014 from a rural area in China.

During a median 6-year follow-up, we recorded 1109 deaths (610 with and 499 without hypertension). In adjusted models, as compared with BMI 22–24 kg/m2, with BMI ≤ 18, 18–20, 20–22, 24–26, 26–28, 28–30 and >30 kg/m2, the hazard ratios for mortality in normotensive participants were 1·92 (95% CI 1·23, 3·00), 1·44 (95% CI 1·01, 2·05), 1·14 (95% CI 0·82, 1·58), 0·96 (95% CI 0·70, 1·31), 0·96 (95% CI 0·65, 1·43), 1·32 (95% CI 0·81, 2·14) and 1·32 (95% CI 0·74, 2·35), respectively, and in hypertensive participants were 1·85 (95% CI 1·08, 3·17), 1·67 (95% CI 1·17, 2·39), 1·29 (95% CI 0·95, 1·75), 1·20 (95% CI 0·91, 1·58), 1·10 (95% CI 0·83, 1·46), 1·10 (95% CI 0·80, 1·52) and 0·61 (95% CI 0·40, 0·94), respectively. The risk of mortality was lower in individuals with hypertension with overweight or obesity v. normal weight, especially in older hypertensives (≥60 years old). Sensitivity analyses gave consistent results for both normotensive and hypertensive participants.

Low BMI was significantly associated with increased risk of all-cause mortality regardless of hypertension status in rural Chinese adults, but high BMI decreased the mortality risk among individuals with hypertension, especially in older hypertensives.

Family coaggregation of attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), bipolar disorder (BD), major depressive disorder (MDD) and schizophrenia have been presented in previous studies. The shared genetic and environmental factors among psychiatric disorders remain elusive.

This nationwide population-based study examined familial coaggregation of major psychiatric disorders in first-degree relatives (FDRs) of individuals with ASD. Taiwan's National Health Insurance Research Database was used to identify 26 667 individuals with ASD and 67 998 FDRs of individuals with ASD. The cohort was matched in 1:4 ratio to 271 992 controls. The relative risks (RRs) and 95% confidence intervals (CI) of ADHD, ASD, BD, MDD and schizophrenia were assessed among FDRs of individuals with ASD and ASD with intellectual disability (ASD-ID).

FDRs of individuals with ASD have higher RRs of major psychiatric disorders compared with controls: ASD 17.46 (CI 15.50–19.67), ADHD 3.94 (CI 3.72–4.17), schizophrenia 3.05 (CI 2.74–3.40), BD 2.22 (CI 1.98–2.48) and MDD 1.88 (CI 1.76–2.00). Higher RRs of schizophrenia (4.47, CI 3.95–5.06) and ASD (18.54, CI 16.18–21.23) were observed in FDRs of individuals with both ASD-ID, compared with ASD only.

The risk for major psychiatric disorders was consistently elevated across all types of FDRs of individuals with ASD. FDRs of individuals with ASD-ID are at further higher risk for ASD and schizophrenia. Our results provide leads for future investigation of shared etiologic pathways of ASD, ID and major psychiatric disorders and highlight the importance of mental health care delivered to at-risk families for early diagnoses and interventions.

Whether the first-degree relatives (FDRs) of patients with obsessive-compulsive disorder (OCD) have an increased risk of the major psychiatric disorders, namely schizophrenia, bipolar disorder, OCD, major depressive disorder (MDD), autism spectrum disorder (ASD), and attention deficit hyperactivity disorder (ADHD), remains unclear.

Using the Taiwan National Health Insurance Research Database with the whole population sample size (n = 23 258 175), 89 500 FDRs, including parents, offspring, siblings, and twins, of patients with OCD were identified in our study. The relative risks (RRs) of major psychiatric disorders were assessed among FDRs of patients with OCD.

FDRs of patients with OCD had higher RRs of major psychiatric disorders, namely OCD (RR 8.11, 95% confidence interval (CI) 7.68–8.57), bipolar disorder (RR 2.85, 95% CI 2.68–3.04), MDD (RR 2.67, 95% CI 2.58–2.76), ASD (RR 2.38, 95% CI 2.10–2.71), ADHD (RR 2.19, 95% CI 2.07–2.32), and schizophrenia (RR 1.97, 95% CI 1.86–2.09), compared with the total population. Different familial kinships of FDRs, such as parents, offspring, siblings, and twins consistently had increased risks for these disorders. In addition, a dose-dependent relationship was found between the numbers of OCD probands and the risk of each major psychiatric disorder.

The FDRs, including parents, offspring, siblings, and twins, of patients with OCD have a higher risk of OCD, schizophrenia, bipolar disorder, MDD, ADHD, and ASD. The familial co-aggregation of OCD with OCD and other major psychiatric disorders was existent in a dose-dependent manner. Given the increased risks of psychiatric disorders, medical practitioners should closely monitor the mental health of the FDRs of patients with OCD.

Health system reform is considered a tough issue worldwide. Great efforts have been made toward health system building and strengthening. However, it is still unclear which health system is appropriate for different countries. This study aimed to systematically compare the characteristics of the establishment periods between eighty-eight counties of National Health Service (NHS) and Social Health Insurance (SHI).

Forty-eight NHS countries and forty SHI countries with data availability were selected. The establishment years of current health systems and other eighteen indicators in economics, society, population and health during establishment periods were collected. Comparison between NHS and SHI was conducted by descriptive analysis of every indicator.

Most NHS countries were established during the cold war, while SHI had been set up since the cold war ended. The median of gross domestic product (GDP) per capita, urbanization rate and aging rate of SHI were USD 1535 in current dollars, 58.2 percent and 9.8 percent, respectively; compared with USD 1387, 41.2 percent and 4.7 percent, respectively of NHS. NHS countries had a smaller total population, lower mortality rate and elderly dependency ratio, while the birth rate and children's dependency ratio were higher. SHI countries showed a higher life expectancy and lower mortality rate in infants and children. NHS countries spent less in total health expenditure and a lower proportion of GDP. The median health expenditure per capita of SHI and NHS were USD 188 and USD 131 in current dollars, respectively. There was little difference among maternal mortality rates, and public and private health expenditure proportions.

NHS and SHI countries had different characteristics during the health system establishment periods. NHS was established earlier than SHI overall, so that SHI revealed higher levels in economic and social development. Health outcomes of NHS countries were slightly lower than SHI ones, while health expenditure was more in SHI countries. Specific social, economic, demographic and health conditions should be considered when countries are building their own health systems.

Research suggests an association between metabolic disorders, such as type 2 diabetes mellitus (T2DM), and schizophrenia. However, the risk of metabolic disorders in the unaffected siblings of patients with schizophrenia remains unclear.

Using the Taiwan National Health Insurance Research Database, 3135 unaffected siblings of schizophrenia probands and 12,540 age-/sex-matched control subjects were included and followed up to the end of 2011. Individuals who developed metabolic disorders during the follow-up period were identified.

The unaffected siblings of schizophrenia probands had a higher prevalence of T2DM (3.4% vs. 2.6%, p = 0.010) than the controls. Logistic regression analyses with the adjustment of demographic data revealed that the unaffected siblings of patients with schizophrenia were more likely to develop T2DM (odds ratio [OR]: 1.39, 95% confidence interval [CI]: 1.10–1.75) later in life compared with the control group. Moreover, only female siblings of schizophrenia probands had an increased risk of hypertension (OR: 1.47, 95% CI: 1.07–2.01) during the follow-up compared with the controls.

The unaffected siblings, especially sisters, of schizophrenia probands had a higher prevalence of T2DM and hypertension compared with the controls. Our study revealed a familial link between schizophrenia and T2DM in a large sample. Additional studies are required to investigate the shared pathophysiology of schizophrenia and T2DM.

Bipolar disorder is a highly heritable mental illness that transmits intergeneratively. Previous studies supported that first-degree relatives (FDRs), such as parents, offspring, and siblings, of patients with bipolar disorder, had a higher risk of bipolar disorder. However, whether FDRs of bipolar patients have an increased risk of schizophrenia, major depressive disorder (MDD), autism spectrum disorder (ASD), and attention deficit hyperactivity disorder (ADHD) remains unclear.

Among the entire population in Taiwan, 87 639 patients with bipolar disorder and 188 290 FDRs of patients with bipolar disorder were identified in our study. The relative risks (RRs) of major psychiatric disorders were assessed among FDRs of patients with bipolar disorder.

FDRs of patients with bipolar disorder were more likely to have a higher risk of major psychiatric disorders, including bipolar disorder (RR 6.12, 95% confidence interval (CI) 5.95–6.30), MDD (RR 2.89, 95% CI 2.82–2.96), schizophrenia (RR 2.64, 95% CI 2.55–2.73), ADHD (RR 2.21, 95% CI 2.13–2.30), and ASD (RR 2.10, 95% CI 1.92–2.29), than the total population did. These increased risks for major psychiatric disorders were consistent across different familial kinships, such as parents, offspring, siblings, and twins. A dose-dependent relationship was also found between risk of each major psychiatric disorder and numbers of bipolar patients.

Our study was the first study to support the familial coaggregation of bipolar disorder with other major psychiatric disorders, including schizophrenia, MDD, ADHD, and ASD, in a Taiwanese (non-Caucasian) population. Given the elevated risks of major psychiatric disorders, the public health government should pay more attention to the mental health of FDRs of patients with bipolar disorder.