The Frontiers of Suicide

Association between suicidal ideation and tandem repeats in contactins

Background

Death by suicide is one of the leading causes of death among adolescents. Genome-wide association studies (GWAS) have identified loci that associate with suicidal ideation and related behaviours. One such group of loci are the six contactin genes (CNTN1-6) that are critical to neurodevelopment through regulating neurite structure. Because single nucleotide polymorphisms (SNPs) detected by GWAS often map to non-coding intergenic regions, we investigated whether repetitive variants in CNTNs associated with suicidality in a young cohort aged 8 to 21. Understanding the genetic liability of suicidal thought and behavior in this age group will promote early intervention and treatment.

Methods

Genotypic and phenotypic data were obtained from the Philadelphia Neurodevelopment Cohort (PNC). Across six CNTNs, 232 short tandem repeats (STRs) were analyzed in up to 4,595 individuals of European ancestry who expressed current, previous, or no suicidal ideation. STRs were imputed into SNP arrays using a phased SNP-STR haplotype reference panel from the 1000 Genomes Project. We tested several additive and interactive models of locus-level burden (i.e., sum of STR alleles) with respect to suicidal ideation. Additive models included sex, birth year, developmental stage ("DevStage"), and the first 10 principal components of ancestry as covariates; interactive models assessed the effect of STR-by-DevStage considering all other covariates.

Results

CNTN1-[T]N interacted with DevStage to increase risk for current suicidal ideation (CNTN1-[T]N-by-DevStage; p = 0.00035). Compared to the youngest age group, the middle (OR = 1.80, p = 0.0514) and oldest (OR = 3.82, p = 0.0002) participant groups had significantly higher odds of suicidal ideation as their STR length expanded; this result was independent of polygenic scores for suicidal ideation.

Discussion

These findings highlight diversity in the genetic effects (i.e., SNP and STR) acting on suicidal thoughts and behavior and advance our understanding of suicidal ideation across childhood and adolescence.

Secular trends of suicide risk for residents in mainland China (2004 to 2019): An updated age-period-cohort analysis

BACKGROUND

The overall suicide rate in China has dropped substantially since the 1990s, but a slowdown in the decrease and even a reversing trend was observed in specific groups in recent years. This study aims to investigate the latest suicide risk in mainland China by using the age-period-cohort (APC) analysis.

METHOD

This population-based multiyear cross-sectional study included Chinese ages 10 to 84 years using data from the China Health Statistical Yearbook (2005-2020). Data were analyzed by the APC analysis and intrinsic estimator (IE) technique.

RESULTS

The data satisfactorily fit the constructed APC models. The cohort effect indicated a high risk of suicide among people birth in 1920-1944 and a sharp decline in the 1945-1979 cohort. The lowest risk occurred in the 1980-1994 cohort before a sharp increase in generation Z (birth years in 1995-2009). The period effect showed a declining trend since 2004. The age effect indicated that the suicide risk increased over time, except for a gradual decline from age 35 to 49. The suicide risk increased greatly in adolescents and reached the highest among the elderly.

LIMITATIONS

The aggregated population-level data and the non-identifiability of the APC model could result in bias in the accuracy of results in this study.

CONCLUSIONS

This study successfully updated the Chinese suicide risk from the age, period and cohort perspective using the latest available data (2004-2019). The findings enhance the understanding of suicide epidemiology and provide evidence supporting policies and strategies at the macro-level for suicide prevention and management. Immediate action is needed to focus on a national suicide prevention strategy that targets generation Z, adolescents and the elderly which will require a collaborative effort by government officials, public/community health planners and health care agencies.

Suicidal behavior sociocultural factors in developing countries during COVID-19

Objectives

Sociocultural factors in the aftermath of any pandemic can play a role in increasing suicidal behavior like suicidal ideation, suicidal attempts, or suicide. The authors discuss the risk and predisposing factors for suicidal ideation among mental health patients in four developing countries (Bangladesh, Colombia, India and Pakistan), this aims to grasp the heterogeneity of these motivators and to elaborate specific interventions regarding suicide in the COVID-19 pandemic.

Methods

We searched PubMed, Medline, and Google Scholar through March, 2021 for articles using a combination of the keywords and generic terms for suicide, suicide ideation, COVID-19, developing countries, low-middle-income countries, Sociocultural factors, Suicidal behavior, predisposing factors and predictive factors, for articles in English language only, and without publication time restriction.

Results

This narrative review summarizes the sociocultural risk and predisposing factors for suicidal behavior in developing countries during the COVID-19 pandemic. The findings reveal those factors such as fear of being infected, growing economic pressure, lack of resources due to lockdown are mostly responsible in the four countries for the current increase in suicides. There are a few cultural differences that are specified in the narrative.

Conclusion

The COVID-19 pandemic is a public health challenge, in which prevention and intervention of suicidal behavior have been suboptimal, especially in low-middle-income countries. Based on literature results, we provide practical suggestions (e.g., reducing infodemic, specialized helplines, improving mental health services availability) in order to tackle main challenges of suicide prevention, such as lack of adequate manpower, fragile health system and poverty.

Depression and suicidal ideation among the geriatric population of Kashmir, India

BACKGROUND

Depression is a common disorder that can lead to suicidal behaviours among the geriatric population.

AIM

We aimed to assess depression, hopelessness, and suicidal ideation among the elderly population of Kashmir.

METHODS

A community-based cross-sectional study was conducted in three districts of Kashmir between June and August 2019. The sample consisted of 200 persons aged >65 years. Beck's Depression Inventory, Beck's Hopelessness Scale, and the Beck Suicide Ideation scale were used to determine depression, hopelessness, and suicide ideation. Pearson's correlation was performed to assess the relationships between depression, hopelessness, and suicide.

RESULTS

The prevalence of severe depression with a score of ⩾31 on Beck's Depression Inventory was 56% among the studied population. Most of these elderly were found to have moderate levels of suicidal ideation (62.5%) and hopelessness (61%). Depression had a positive correlation with suicidal ideation (r = 0.35). Hopelessness and suicidal intent had a more significant positive correlation (r = 0.54), as compared to depression and hopelessness (r = 0.43).

CONCLUSION

More than half of the older persons in Kashmir had depression with superimposed hopelessness which is an important risk factor of suicidal ideation.