Body Mass Index Is an Important Predictor for Suicide: Results from a Systematic Review and Meta-Analysis

Suicidal thoughts and attempts in a transdiagnostic eating disorder sample: Do diagnostic severity criteria predict risk?

OBJECTIVE

Eating disorders (EDs) are associated with elevated suicide. Low body mass index (BMI) and frequency of purging and binge eating represent severity criteria for EDs and distinguish full-threshold EDs from other specified feeding and eating disorders (OSFED). However, no work has taken a transdiagnostic approach to studying whether severity of these or other features is associated with suicidal ideation (SI) and attempts.

METHOD

We examined diagnostic status, ED features, and SI and attempts in a large, transdiagnostic, community sample of 257 women with EDs and 45 controls without a current or past ED in the United States using the EDs Examination interview and the Structured Clinical Interview for the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders).

RESULTS

SI and suicide attempts (SA) were elevated in OSFED compared to controls but did not differ between OSFED and full-threshold EDs. Higher BMI predicted increased SI. Number of purging methods, but not frequency, was related to history of SA. Binge episode frequency and size were not significant predictors.

CONCLUSIONS

OSFED presents with elevated SI and SA, and ED severity criteria that distinguish OSFED from full-threshold EDs do not predict SI or SA. Suicide risk assessments should be implemented universally across EDs in clinical practice.

Suicidal ideation in female individuals with fibromyalgia and comorbid obesity: prevalence and association with clinical, pain-related, and psychological factors

OBJECTIVE

Individuals with fibromyalgia report alarming levels of suicidal ideation, and comorbidity with other chronic health conditions such as obesity-a risk factor for suicidal ideation per se-could further complicate the clinical picture. The aim of this study is to determine, in a sample of women with fibromyalgia and comorbid obesity, the prevalence of suicidal ideation and to evaluate clinical, pain-related and psychological factors associated with suicidal ideation.

METHODS

In total, 156 female individuals with fibromyalgia and obesity were recruited and completed a series of self-report measures that assessed (i) the level of pain intensity, (ii) depressive symptomatology, (iii) sleep quality, and (iv) pain catastrophizing. Suicidal ideation was evaluated by item #9 of the Beck Depression Inventory. In addition, information regarding previous suicide attempts and current opioid use was collected.

RESULTS

3n sum, 7.8% of participants reported presence of suicidal ideation. According to the results of the multiple logistic regression, depressive symptomatology, sleep quality, and pain catastrophizing were associated with the presence of suicidal ideation.

DISCUSSION

The presence of suicidal ideation in our sample was significantly associated with depressive symptomatology, sleep quality, and pain catastrophizing. Our findings are the first to suggest a unique (ie, independent of depressive symptomatology, and sleep quality) association between pain catastrophizing and suicidal ideation in the context of fibromyalgia and comorbid obesity. In order to prevent and reduce suicidal ideation, these factors should be assessed and targeted in interventions for pain management. Future research should investigate the extent to which addressing depressive symptoms, sleep quality, and pain catastrophizing reduces suicidal ideation.

The impact of body mass index on the clinical features of bipolar disorder: A STEP-BD study

INTRODUCTION

The effects of body mass index (BMI) on the core symptoms of bipolar disorder (BD) and its implications for disease trajectory are largely unexplored.

OBJECTIVE

To examine whether BMI impacted hospitalization rate, medical and psychiatric comorbidities, and core symptom domains such as depression and suicidality in BD.

METHODS

Participants (15 years and older) were 2790 BD outpatients enrolled in the longitudinal STEP-BD study; all met DSM-IV criteria for BD-I, BD-II, cyclothymia, BD NOS, or schizoaffective disorder, bipolar subtype. BMI, demographic information, psychiatric and medical comorbidities, and other clinical variables such as bipolarity index, history of electroconvulsive therapy (ECT), and history of suicide attempts were collected at baseline. Longitudinal changes in Montgomery-Åsberg Depression Rating Scale (MADRS) score, Young Mania Rating Scale (YMRS) score, and hospitalizations during the study were also assessed. Depending on the variable of interest, odds-ratios, regression analyses, factor analyses, and graph analyses were applied.

RESULTS

A robust increase in psychiatric and medical comorbidities was observed, particularly for baseline BMIs >35. A significant relationship was noted between higher BMI and history of suicide attempts, and individuals with BMIs >40 had the highest prevalence of suicide attempts. Obese and overweight individuals had a higher bipolarity index (a questionnaire measuring disease severity) and were more likely to have received ECT. Higher BMIs correlated with worsening trajectory of core depression symptoms and with worsening lassitude and inability to feel.

CONCLUSIONS

In BD participants, elevated BMI was associated with worsening clinical features, including higher rates of suicidality, comorbidities, and core depression symptoms.

Age-Dependent Association Between Body Mass Index and All-Cause Mortality Among Patients with Hypertension: A Longitudinal Population-Based Cohort Study in China

PURPOSE

The association between body mass index (BMI) and all-cause mortality may vary among hypertensive patients of different ages. This study aimed to investigate the age-dependent association between BMI and all-cause mortality among patients with hypertension.

PATIENTS AND METHODS

A total of 212,394 participants with hypertension aged 20-85 years from Minhang Hypertension Standardization Management System in Shanghai of China were included. Follow-up began at the time when individuals were first recorded and ended at death, loss to follow-up, or December 31, 2018, whichever came first. Additive Cox proportional hazards models with thin plate smoothing functions and conventional Cox proportional hazards models were adopted to examine the relationship between BMI, age, and mortality. The joint effect of BMI and age on mortality was assessed using a bivariate response model.

RESULTS

We found that the BMI-mortality relationship followed a U-shaped pattern, with a trough at 26-27 kg/m2. Compared with normal weight, underweight was associated with a 50% increased risk of premature mortality (hazard ratio 1.50, 95% confidence interval 1.43 to 1.57). Whereas among those aged 45-59 and 60-85 years, overweight was associated with 13% (0.87, 0.80 to 0.94) and 18% (0.82, 0.80 to 0.84) reduction in risk of death, respectively. Bivariate response model indicated a significant interaction between BMI and age (P < 0.05). Among younger and older patients, we found a descending trend for mortality risk, with BMI increasing at different age levels, whereas a reverse J-shaped relation pattern was observed among middle-aged patients.

CONCLUSION

The impact of BMI on all-cause mortality in hypertensive patients varies with age, and moderate weight gain may benefit longevity in middle-aged and older patients.

The Mental "Weight" of Discrimination: The Relationship between Perceived Interpersonal Weight Discrimination and Suicidality in the United States

Extant research has investigated the relationship between body weight and suicidality because obesity is highly stigmatized, leading to social marginalization and discrimination, yet has produced mixed results. Scholars have speculated that factors associated with body weight, such as weight discrimination, may better predict suicidality than body weight itself. We consider this possibility among a sample of 12,057 adult participants ages 33 to 43 in Wave V of the National Longitudinal Study of Adolescent to Adult Health through investigation of the relationships between weight discrimination and two dimensions of suicidality-suicide ideation and attempts. We also examine gender as a moderator of these relationships. We find that weight discrimination is positively associated with both suicide ideation and attempts, and this relationship is similar among men and women. Our findings underscore the need to address issues of weight discrimination in our society to better promote mental well-being.

Individual-level risk factors for suicide mortality in the general population: an umbrella review

BACKGROUND

Deaths by suicide remain a major public health challenge worldwide. Identifying and targeting risk factors for suicide mortality is a potential approach to prevention. We aimed to summarise current knowledge on the range and magnitude of individual-level risk factors for suicide mortality in the general population and evaluate the quality of the evidence.

METHODS

In this umbrella review, five bibliographic databases were systematically searched for articles published from database inception to Aug 31, 2022. We included meta-analyses of observational studies on individual-level risk factors for suicide mortality in the general population. Biological, genetic, perinatal, and ecological risk factors were beyond the scope of this study. Effect sizes were synthesised and compared across domains. To test robustness and consistency of the findings, evidence for small-study effects and excess significance bias (ie, the ratio between the overall meta-analysis effect size and that of its largest included study) was examined, and prediction intervals were calculated. Risk of bias was assessed by the Risk of Bias in Systematic Reviews instrument. The protocol was pre-registered with PROSPERO (CRD42021230119).

FINDINGS

We identified 33 meta-analyses on 38 risk factors for suicide mortality in the general population. 422 (93%) of the 454 primary studies included in the meta-analyses were from high-income countries. A previous suicide attempt and suicidal ideation emerged as strong risk factors (with effect sizes ranging from 6 to 16). Psychiatric disorders were associated with a greatly elevated risk of suicide mortality, with risk ratios in the range of 4-13. Suicide risk for physical illnesses (such as cancer and epilepsy) and sociodemographic factors (including unemployment and low education) were typically increased two-fold. Contact with the criminal justice system, state care in childhood, access to firearms, and parental death by suicide also increased the risk of suicide mortality. Among risk factors for which sex-stratified analyses were available, associations were generally similar for males and females. However, the quality of the evidence was limited by excess significance and high heterogeneity, and prediction intervals suggested poor replicability for almost two-thirds of identified risk factors.

INTERPRETATION

A wide range of risk factors were identified across various domains, which underscores suicide mortality as a multifactorial phenomenon. Prevention strategies that span individual and population approaches should account for the identified factors and their relative strengths. Despite the large number of risk factors investigated, few associations were supported by robust evidence. Evidence of causal inference will need to be tested in high-quality study designs.

FUNDING

Wellcome Trust.

Association of Body Mass Index and Cardiometabolic Factors With Elderly Suicide: A Cohort Study of 101,518 Older Taiwanese

BACKGROUND

Older people have the highest suicide rate across age groups in most countries. The prevalence of cardiometabolic risk factors also increases with age. We investigated the association between body mass index (BMI), cardiometabolic risk factors, and suicide in a large cohort of older people in Taiwan.

METHODS

We conducted a cohort study using data from an elderly health examination program in Taipei City, Taiwan (2005-2010), linked to the national cause-of-death data files. We used competing risk Cox regression models to investigate the associations of BMI (kg/m2) and cardiometabolic factors with suicide after adjusting for sex, age, socioeconomic variables, chronic diseases, psychological distress, and cognitive function.

RESULTS

Among 101,518 individuals aged ≥ 65 years, 92 died by suicide during an average follow-up of 3.9 years. Underweight (BMI<18.5) was associated with increased suicide risk (adjusted hazard ratio [aHR]=2.33, 95% confidence interval [CI] 1.20-4.52) (reference: normal weight). Low diastolic blood pressure was associated with increased suicide risk - aHR was 0.51 (95% CI 0.29-0.91) and 0.55 (95% CI 0.31-0.99) for the third and fourth quartiles of diastolic blood pressure (reference: the lowest quartile), respectively. Older people with a higher waist circumference (aHR per 1-standard-deviation increase=0.60 [95% CI 0.37-0.98]) and a higher number of metabolic syndrome criteria (aHR per 1-criterion increase=0.65 [95% 0.46-0.92]) had lower suicide risk. Systolic blood pressure, pulse rate, fasting blood glucose, and lipid profiles were not associated with suicide risk.

CONCLUSIONS

Underweight, low diastolic blood pressure, and low waist circumference may be markers of increased suicide risk in older people.

Association between body mass index and suicide attempts in Chinese patients of a hospital in Shanxi district with first-episode drug-naïve major depressive disorder

OBJECTIVE

In patients with major depressive disorder (MDD), the relationship between body mass index (BMI) and risk of suicide attempts (SA) remains unclear, and findings are controversial. The aim of this study was to investigate the relationship between BMI and SA in a Chinese population with first-episode drug-naïve (FEDN) MDD.

METHODS

A total of 1718 patients with FEDN MDD were enrolled in this cross-sectional study. Their socio-demographic characteristics as well as anthropometric data were collected. The 17-item Hamilton Rating Scale (HAMD-17) and Hamilton Anxiety Scale (HAMA) were used to assess the severity of depression and anxiety symptoms in all participants. Thyroid hormones, lipid profile, and fasting blood glucose (FBG) were measured. A history of suicide attempts was verified based on medical records and interviews with patients and their family members. Multiple logistic regression analysis was used to estimate the association between BMI and the risk of SA. Threshold effects were examined by a two-piecewise logistic regression model.

RESULTS

Multiple logistic regression analysis showed that BMI was independently and negatively correlated with SA (OR = 0.91, 95%CI: 0.85 to 0.98, P = 0.01) in patients with FEDN MDD after adjusting for covariates. Smoothing plots also revealed a non-linear (L-shaped) relationship between BMI and SA, and a two-piecewise logistic regression model was used to calculate the inflection point of BMI as 22.1 kg/m2. On the left of the inflection point, a negative association between BMI and SA was detected (OR = 0.54, 95%CI: 0.42 to 0.70, P < 0.001), while no significant association was observed on the right side of the inflection point (OR = 1.01, 95%CI: 0.93 to 1.10, P = 0.75).

CONCLUSIONS

Our results suggest that lower BMI is associated with a higher risk of recent SA in Chinese patients with FEDN MDD, especially in those with BMI below 22.1 kg/m2.

Gender differences in the association between body mass index and recent suicide attempts in Chinese patients with first-episode drug-naïve major depressive disorder

Controversial evidence exists on the relationship between body mass index (BMI) and suicide attempts (SA) in patients with major depressive disorder (MDD). This cross-sectional study aimed to explore the association between BMI and SA in first-episode drug-naïve (FEDN) MDD patients in China. The study was conducted from 2016 to 2018 in Taiyuan, China. Univariate and multivariate logistic regression analyzed the BMI-SA association, with subgroup analysis for gender. Threshold effects were examined using two-piecewise regression. In males, BMI was significantly associated with SA (OR = 0.84, 95% CI 0.74-0.94, P = 0.003) after full adjustment, but not in females (OR = 0.97, 95% CI 0.89-1.06, P = 0.541). The interaction with gender was significant (P for interaction < 0.05). Smoothing plots revealed an L-shaped BMI-SA relationship in both genders, with BMI inflection points at 27.3 kg/m2 in males and 21.4 kg/m2 in females. Below the inflection points, BMI is negatively associated with SA in males (OR = 0.75, 95% CI 0.66-0.86, P < 0.001) and females (OR = 0.48, 95% CI 0.32-0.72, P < 0.001). Above the inflection points, no association existed for both genders (all P > 0.05). Results showed an L-shaped nonlinear BMI-SA relationship in FEDN MDD patients but differing BMI inflection points between genders, thus contributing to effective prevention programs for suicide.

Body mass index and clinical outcomes in individuals with major depressive disorder: Findings from the GSRD European Multicenter Database

BACKGROUND

Individuals with major depressive disorder (MDD) are at higher risk for obesity. In turn, weight gain is a predisposing factor for depression. Although clinical data are sparse, suicide risk also appears to be elevated in obese patients. This study used data from the European Group for the Study of Resistant Depression (GSRD) to investigate clinical outcomes associated with body mass index (BMI) in MDD.

METHODS

Data were drawn from 892 participants with MDD over the age of 18 years (580 female, 50.5 ± 13.6 years). Response and resistance to antidepressant medication, depression rating scale scores, and further clinical and sociodemographic variables were compared using multiple logistic and linear regressions controlled for age, sex, and risk of weight gain due to psychopharmacotherapy.

RESULTS

Of the 892 participants, 323 were categorized as treatment-responsive and 569 as treatment-resistant. Within this cohort, 278 (31.1 %) were overweight (BMI = 25-29.9 kg/m2) and 151 (16.9 %) were obese (BMI > 30 kg/m2). Elevated BMI was significantly associated with higher suicidality, longer duration of psychiatric hospitalizations over their lifetimes, earlier age of onset of MDD, and comorbidities. There was a trend-wise association of BMI with treatment resistance.

LIMITATIONS

Data were analyzed in a retrospective, cross-sectional design. BMI was used as an exclusive measure of overweight and obesity.

CONCLUSIONS

Participants with comorbid MDD and overweight/obesity were at risk for worse clinical outcomes, suggesting that weight gain should be closely monitored in individuals with MDD in daily clinical practice. Further studies are needed to explore the neurobiological mechanisms linking elevated BMI to impaired brain health.

Non-suicidal self-injuries and suicide risk in adolescent girls with eating disorders: associations with weight control, body mass index, and interpersonal sensitivity

BACKGROUND

Eating disorders (EDs) are associated with a risk of premature death, as well as suicidal and self-injurious behavior. A low or high body mass index (BMI) and weight control behavior can also have an impact on self-injurious and suicidal behavior. While some studies show that interpersonal sensitivity is a risk factor for EDs, affective disorders, and self-injurious behavior, in-depth studies of these issues have not been done.

AIM

The present study investigates how self-injurious and suicidal behavior relate to weight control behavior, BMI, and interpersonal sensitivity in adolescent girls from a clinical population with diagnosed EDs compared with adolescent girls from the general population.

METHODS

The main group was comprised of 31 girls with a diagnosis of ED (as the main diagnosis or co-occurring with affective disorders, M=151.13 years), being treated in in the Eating Disorder Clinic of the Scientific and Practical Center for Mental Health of Children and Adolescents named after G.E. Sukhareva. The comparison group consisted of 27 adolescent girls recruited from Proton Educational Center (M=15.511.09 years). The measures included a qualitative survey that yielded data on weight control behavior, and self-injurious behavior, a Blitz questionnaire probing the suicide risk (used only in the main group), and the Interpersonal Sensitivity Measure. Height and weight data were also recorded for BMI calculation.

RESULTS

The qualitative analysis of weight control behavior yielded the following results: purging behavior, restrictive behavior, and corrective behavior. Participants in the main group used purging and restrictive behavior more often, whereas participants in the comparison group used strategies associated with a healthy lifestyle. The main group and participants who practiced purging and restrictive weight control in the overall sample had the smallest BMI. Self-injurious behavior was approximately evenly distributed both amongst the main and comparison groups. Self-cutting was the most prevalent type of self-injury. In the main group, self-injury was associated with a smaller BMI, while in the comparison group it was associated with an increase in the fear of rejection and overall interpersonal sensitivity. Based on the assessment of the suicide risk, six participants in the main group were deemed high-risk; they also displayed increased fear of rejection, dependence on the assessments of others, and overall interpersonal sensitivity. All girls in the suicide risk subgroup had non-suicidal self-injuries.

CONCLUSION

The results of our study broaden our understanding of the risk factors of suicidal and self-injurious behavior in adolescent girls with EDs and reveal the characteristics of the type of weight control behavior used by this group in comparison with adolescent girls in the general population. Girls with EDs who were considered at the risk of committing suicide demonstrated high interpersonal sensitivity, which provides a rationale for further studying the general interpersonal mechanisms that underlie the pathogenesis of EDs, as well as that of self-injurious and suicidal behavior.

Weight loss as a risk factor for suicide. A prospective cohort study in more than 200,000 adults

This study examined the association of changes in body weight with suicide mortality in 214,105 participants, aged 18-97 years, from the MJ cohort, Taiwan. During a mean follow-up of 15.0 ± 4.9 years, 239 participants died for suicide. Mean change in body weight was 0.29 ± 1.8 Kg/year. A nonlinear dose-response relationship between changes in body weight and suicide was detected (p < 0.001), so that incidence of suicide raised when body weight decreased. The HR (95%CI) per 1 kg/year of weight loss was 1.35 (1.03-1.75) for underweight participants. These findings highlight that weight loss could be a risk factor for suicide, especially among underweight people.

Prediction of Suicidal Behaviors in the Middle-aged Population: Machine Learning Analyses of UK Biobank

BACKGROUND

Suicidal behaviors, including suicide deaths and attempts, are major public health concerns. However, previous suicide models required a huge amount of input features, resulting in limited applicability in clinical practice.

OBJECTIVE

We aimed to construct applicable models (ie, with limited features) for short- and long-term suicidal behavior prediction. We further validated these models among individuals with different genetic risks of suicide.

METHODS

Based on the prospective cohort of UK Biobank, we included 223 (0.06%) eligible cases of suicide attempts or deaths, according to hospital inpatient or death register data within 1 year from baseline and randomly selected 4460 (1.18%) controls (1:20) without such records. We similarly identified 833 (0.22%) cases of suicidal behaviors 1 to 6 years from baseline and 16,660 (4.42%) corresponding controls. Based on 143 input features, mainly including sociodemographic, environmental, and psychosocial factors; medical history; and polygenic risk scores (PRS) for suicidality, we applied a bagged balanced light gradient-boosting machine (LightGBM) with stratified 10-fold cross-validation and grid-search to construct the full prediction models for suicide attempts or deaths within 1 year or between 1 and 6 years. The Shapley Additive Explanations (SHAP) approach was used to quantify the importance of input features, and the top 20 features with the highest SHAP values were selected to train the applicable models. The external validity of the established models was assessed among 50,310 individuals who participated in UK Biobank repeated assessments both overall and by the level of PRS for suicidality.

RESULTS

Individuals with suicidal behaviors were on average 56 years old, with equal sex distribution. The application of these full models in the external validation data set demonstrated good model performance, with the area under the receiver operating characteristic (AUROC) curves of 0.919 and 0.892 within 1 year and between 1 and 6 years, respectively. Importantly, the applicable models with the top 20 most important features showed comparable external-validated performance (AUROC curves of 0.901 and 0.885) as the full models, based on which we found that individuals in the top quintile of predicted risk accounted for 91.7% (n=11) and 80.7% (n=25) of all suicidality cases within 1 year and during 1 to 6 years, respectively. We further obtained comparable prediction accuracy when applying these models to subpopulations with different genetic susceptibilities to suicidality. For example, for the 1-year risk prediction, the AUROC curves were 0.907 and 0.885 for the high (>2nd tertile of PRS) and low (<1st) genetic susceptibilities groups, respectively.

CONCLUSIONS

We established applicable machine learning-based models for predicting both the short- and long-term risk of suicidality with high accuracy across populations of varying genetic risk for suicide, highlighting a cost-effective method of identifying individuals with a high risk of suicidality.

Bullying victimization and suicide attempts among adolescents in 41 low- and middle-income countries: Roles of sleep deprivation and body mass

Background

Suicide is the fourth leading cause of death for adolescents, and globally, over 75% of completed suicides occur in low- and middle-income countries (LMICs). Bullying has been proven to be closely related to suicide attempts. However, further understanding of the mechanisms underlying the relationship between bullying and adolescents' suicide attempts is urgently needed.

Methods

We used data from the Global School-based Student Health Survey (GSHS) (2010-2017) from 41 LMICs or regions. This study was based on questions assessing bullying victimization, suicide attempts, sleep deprivation, and body mass. Chi-square tests were used to explore the correlations among the main variables. The mediating role of sleep deprivation and the moderating role of body mass index (BMI) were analyzed using PROCESS.

Results

The results showed a positive association between bullying victimization and suicide attempts. Sleep deprivation partially mediated the relationship between the frequency of being bullied and suicide attempts. In addition, sleep deprivation played a full or partial mediating role in the relationship between different types of bullying and suicide attempts. BMI moderated the relationships between the frequency of being bullied and suicide attempts, between being made fun of about one's body and sleep deprivation, and between sleep deprivation and suicide attempts.

Conclusion

Being bullied has a positive effect on suicide attempts, which is mediated by sleep deprivation and moderated by body mass. The results of this study are consistent with the stress-diathesis model of suicide, suggesting that being bullied is one of the stressors of suicide in adolescents, while sleep deprivation and body mass are susceptibility diatheses of suicide. The results are conducive to identifying adolescents at a high risk of suicide, suggesting that there is a need to pay more attention to bullied adolescents, especially their sleep quality and body mass, and design effective intervention measures to improve the current situation of adolescent suicide in LMICs.

Apolipoprotein E genotype, inflammatory biomarkers, and non-psychiatric multimorbidity contribute to the suicidal ideation phenotype in older age. The Salus in Apulia Study

BACKGROUND

Possible relationships between suicidal ideation and biopsychosocial predictors in older age are unclear. In the population-based Salus in Apulia Study, we investigated the relationships among biomarkers, socio-demographic, psychopathological, inflammatory and metabolic characteristics and suicidal ideation in 1252 older subjects.

METHODS

Suicidal ideation was evaluated with the brief version of the Columbia-Suicide Severity Rating Scale. Apolipoprotein E (APOE) genotype and inflammatory profile [interleukin (IL)-6, tumor necrosis factor (TNF)-α, C-reactive protein (CRP)] were evaluated. A machine learning algorithm, the Random Forest (RF), selected potential biopsychosocial factors associated to suicidal ideation.

RESULTS

Suicidal ideators accounted for 2.32 % of subjects, were female, smokers, and obese with multimorbidity. After adjusting for age, gender, education and social dysfunction, logistic regression analyses revealed that suicidal ideation was associated to late-life depression (LLD) (odds ratio:21.71,95 % confidence interval:9.22-51.14). In the full RF model, asthma was the most important contributor to suicidal ideation. In the final RF model, education, age, and mild cognitive impairment followed by gender and global cognition were considered the most important contributors. Among biomarkers, in the final RF model, IL-6 followed by TNF-α, APOE ε4 allele presence, CRP and high-density lipoprotein cholesterol contributed most to suicidal ideation.

LIMITATIONS

A relatively small number of older subjects with suicidal ideation (2.3 %); we did not distinguish between active and passive suicidal ideation.

CONCLUSIONS

Although LLD is a strong determinant of suicidal ideation, other non-psychiatric factors, i.e., serum inflammation biomarkers, APOE ε4 allele, and multimorbidity, should be taken into account when evaluating a suicidal ideation phenotype in older age.

Prediction of suicide attempts in a prospective cohort study with a nationally representative sample of the US population

BACKGROUND

There is still little knowledge of objective suicide risk stratification.

METHODS

This study aims to develop models using machine-learning approaches to predict suicide attempt (1) among survey participants in a nationally representative sample and (2) among participants with lifetime major depressive episodes. We used a cohort called the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) that was conducted in two waves and included a nationally representative sample of the adult population in the United States. Wave 1 involved 43 093 respondents and wave 2 involved 34 653 completed face-to-face reinterviews with wave 1 participants. Predictor variables included clinical, stressful life events, and sociodemographic variables from wave 1; outcome included suicide attempt between wave 1 and wave 2.

RESULTS

The model built with elastic net regularization distinguished individuals who had attempted suicide from those who had not with an area under the ROC curve (AUC) of 0.89, balanced accuracy 81.86%, specificity 89.22%, and sensitivity 74.51% for the general population. For participants with lifetime major depressive episodes, AUC was 0.89, balanced accuracy 81.64%, specificity 85.86%, and sensitivity 77.42%. The most important predictor variables were a diagnosis of borderline personality disorder, post-traumatic stress disorder, and being of Asian descent for the model in all participants; and previous suicide attempt, borderline personality disorder, and overnight stay in hospital because of depressive symptoms for the model in participants with lifetime major depressive episodes. Random forest and artificial neural networks had similar performance.

CONCLUSIONS

Risk for suicide attempt can be estimated with high accuracy.

Prediction of suicidal ideation in shift workers compared to non-shift workers using machine learning techniques

BACKGROUND

Shift work can affect sleep and increase the risk of suicide. This study attempted to predict suicidal ideation according to shift work by using machine learning techniques.

METHODS

We analyzed a total of 43,095 data conducted by using the 10-year Korean National Health and Nutrition Examination Survey (KHANES). Shift workers and daytime workers were categorized and analyzed using random forest (RF) and decision tree (DT) techniques of machine learning techniques.

RESULTS

Shift workers were more than twice as likely to have suicidal ideation as daytime workers. The RF model showed an accuracy of 91.6% for shift workers and 98% for daytime workers. In the DT technique, the rate of suicidal ideation was the highest among shift workers (82.7%) when they were depressed and had an EuroQol-5 Dimension (EQ-5D) score of less than 0.71.

LIMITATIONS

Shift work type was evaluated questionnaire and based on screening data, it was not possible to reflect recent changes in the work type and we evaluated for only suicidal ideation for suicide risk factors.

CONCLUSION

The variables influencing the suicide risk of shift workers and daytime workers differ. In the case of shift workers, negative factors such as depression and low quality of life are risk factors for suicide. Efforts are needed to reduce risk factors through administrative and policy interventions to manage workers' health by early screening.

Does Body Mass Index Confer Risk for Future Suicidal Thoughts and Behaviors? A Meta-analysis of Longitudinal Studies

PURPOSE OF REVIEW

Body mass index (BMI) outside of the "normal" range is commonly cited as a predictor of adverse health outcomes and has been identified as a potential risk factor for suicidal thoughts and behaviors (STBs). This meta-analysis provides a descriptive and quantitative summary of the literature evaluating the longitudinal relationship between BMI/weight status and STBs.

RECENT FINDINGS

The longitudinal literature examining the relationship between BMI/weight status and STBs is small and methodologically constrained. Within the existing literature, BMI and weight status are generally weak or nonsignificant risk factors for STBs. It is possible that body weight has a complex relationship with physical and mental health, including STBs, which may not be possible to accurately capture with a singular metric such as BMI. BMI and weight status do not appear to robustly predict STBs, at least within the methodological constraints of the existing literature.

Suicide Attempts by Poisoning: An Experience From a High-Volume Emergency Department

Background

There has been a tremendous increase in self-poisoning behavior worldwide, with different trends depending on cultural and geographic aspects.

Objectives

Our study aims to assess the trends, outcomes, and predictors in patients of suicide attempts by poisoning at King Abdulaziz Medical City (KAMC) ED.

Materials and methods

A retrospective cohort study took place at KAMC. Frequencies and percentages were used to display categorical variables. Minimum, maximum, mean, and SD were used to display continuous variables. Chi-squared test and independent t-test were utilized to test for factors associated with suicidal intention.

Results

A total of 130 cases were identified. The participants were mostly females (73.8%, n = 96). Most of the participants were pediatric patients (57.7%, n = 75). The most consumed agents were acetaminophen in 59 (45.83%) and non-steroidal anti-inflammatory drugs (NSAIDs) in 22 (16.92%). The ICU admission rate was 8.5% (n = 11). The management for both populations was unspecific, involving observation, supportive measures, and symptomatic treatment. BMI (p < 0.001), gender (p < 0.001), age (p = 0.012), and a history of neuropsychiatric disorders (p < 0.001) were associated factors.

Conclusion

It is crucial that the trends and risk factors of self-poisoning suicide attempts are identified to provide support to those in need. Several variables of interest were noted since the two most observed agents share several key features, such as accessibility and availability. However, contradicting literature reports warrant further investigation to confirm or negate the evidence.

Suicide Biomarkers to Predict Risk, Classify Diagnostic Subtypes, and Identify Novel Therapeutic Targets: 5 Years of Promising Research

BACKGROUND

Suicide is a global health crisis. However, no objective biomarkers of suicide risk currently exist, and self-reported data can be unreliable, which limits prediction, diagnostic, and treatment efforts. Reliable biomarkers that can differentiate between diagnostic subgroups, predict worsening symptoms, or suggest novel therapeutic targets would be extremely valuable for patients, researchers, and clinicians.

METHODS

MEDLINE was searched for reports published between 2016 and 2021 using search terms (suicid*) AND (biomarker*) OR (indicat*). Reports that compared biomarkers between suicidal ideation, suicide attempt, death from suicide, or any suicide subgroup against other neuropsychiatric disorders were included. Studies exclusively comparing suicidal behavior or death from suicide with healthy controls were not included to ensure that biomarkers were specific to suicide and not other psychopathology.

RESULTS

This review summarizes the last 5 years of research into suicide-associated biomarkers and provides a comprehensive guide for promising and novel biomarkers that encompass varying presentations of suicidal ideation, suicide attempt, and death by suicide. The serotonergic system, inflammation, hypothalamic-pituitary-adrenal axis, lipids, and endocannabinoids emerged as the most promising diagnostic, predictive, and therapeutic indicators.

CONCLUSIONS

The utility of diagnostic and predictive biomarkers is evident, particularly for suicide prevention. While larger-scale studies and further in-depth research are required, the last 5 years of research has uncovered essential biomarkers that could ultimately improve predictive strategies, aid diagnostics, and help develop future therapeutic targets.

Identifying long-term and imminent suicide predictors in a general population and a clinical sample with machine learning

BACKGROUND

Machine learning (ML) is increasingly used to predict suicide deaths but their value for suicide prevention has not been established. Our first objective was to identify risk and protective factors in a general population. Our second objective was to identify factors indicating imminent suicide risk.

METHODS

We used survival and ML models to identify lifetime predictors using the Cohort of Norway (n=173,275) and hospital diagnoses in a Saskatoon clinical sample (n=12,614). The mean follow-up times were 17 years and 3 years for the Cohort of Norway and Saskatoon respectively. People in the clinical sample had a longitudinal record of hospital visits grouped in six-month intervals. We developed models in a training set and these models predicted survival probabilities in held-out test data.

RESULTS

In the general population, we found that a higher proportion of low-income residents in a county, mood symptoms, and daily smoking increased the risk of dying from suicide in both genders. In the clinical sample, the only predictors identified were male gender and older age.

CONCLUSION

Suicide prevention probably requires individual actions with governmental incentives. The prediction of imminent suicide remains highly challenging, but machine learning can identify early prevention targets.

Body mass index and the risk of suicidal ideation and suicide attempt among youth in 45 low-and middle-income countries

BACKGROUND

Suicide has become a severe public health issue worldwide. Body weight has been put forward as a potentially modifiable element for suicide thought and behavior. However, there are discrepancies across previous studies. Furthermore, the relationships of body weight with suicidal ideation and suicide attempt among low- and middle-income countries (LMICs) remain unclear. Therefore, we addressed this issue among 104,907 adolescents of 12-15 years old in 45 LMICs.

METHODS

The present study used data from the Global School-based Student Health Survey (GSHS). Suicidal ideation and suicide attempt during the last year were self-reported. Participants were classified intro underweight, normal weight, overweight and obesity according to their body mass index classification. Multivariable logistic regression and meta-analyses based on country-wise estimates were conducted.

RESULTS

The prevalence of suicidal ideation and suicide attempt were 11.8% and 13.0%, respectively. Countrywide meta-analysis demonstrated that overweight and obesity were significantly associated with increased risks of suicidal ideation (For overweight: OR = 1.10; 95% CI = 1.01-1.20; for obesity: OR=1.17; 95%CI: 1.01-1.35) and suicide attempt (For overweight: OR = 1.12; 95% CI = 1.02-1.23; for obesity: OR=1.12; 95%CI: 1.00-1.25). Subgroup analyses showed that the associations between overweight/obesity and suicide attempt were significant for girls but not for boys.

LIMITATIONS

The cross-sectional design cannot explore causality; mental health factors were not assessed; suicidal behaviors were self-reported; significant heterogeneity across countries; only students attending school were included.

CONCLUSIONS

Overweight/obesity was significantly associated with the risk of suicidal ideation and suicide attempt among adolescents in LMICs.

Behavioral risk factors for noncommunicable diseases associated with depression and suicide risk in adolescence

Noncommunicable diseases (NCDs) and mental disorders cooccur in adulthood, which is why their determinants and common risk factors should be addressed at an early age. Therefore, we estimated the association of the major risk factors for NCDs with depression and suicide risk by structural equation modeling considering pathways triggered by social vulnerability or mediated by obesity. This population-based study included 2,515 Brazilian adolescents. The following exposures were the major risk factors for NCDs: substance use behaviors (variable deduced from alcohol, tobacco, and drug use), physical inactivity, and components of unhealthy eating markers (added sugar and saturated fat). Obesity was assessed using the fat mass index. The outcomes were depression and suicide risk. Depression was associated with substance use behaviors (SC = 0.304; p < 0.001), added sugar (SC = 0.094; p = 0.005), and females (SC = 0.310; p < 0.001). Suicide risk was also associated with substance use behaviors (SC = 0.356; p < 0.001), added sugar (SC = 0.100; p = 0.012), and females (SC = 0.207; p < 0.001). In adolescents, these associations may help explain the cluster of NCDs and mental disorders in adulthood.

Methods of attempted suicide and risk factors in LGBTQ+ youth

BACKGROUND

This study aimed to identify patterns of attempted suicide methods and risk factors in lesbian, gay, bisexual, transgender, queer and other gender/sexual minority (LGBTQ+) youth by comparing them to non-LGBTQ+ youth.

METHODS

A total of 9281 Chinese college students completed the study, 8313 participants were included in the analysis of which 1032 were LGBTQ+ youth and 7281 were non-LGBTQ+ youth. Sociodemographic information was collected along with several scales and self-report items. This included anxiety scores using the Generalized Anxiety Disorder (GAD)-7, depression scores using the Patient Health Questionnaire (PHQ)-9, mania score using the Altman Self-Rating Mania (ASRM), Childhood Trauma Questionnaire (CTQ), and Intimate Partner Violence (IPV) victimization using the World Health Organization's definition. Self-report items were used to further collect history of non-fatal self-injurious behaviors, parents' related risk factors, history of suicide attempts, and methods of attempted suicide.

RESULTS

The prevalence of attempted suicide in LGBTQ+ youth was 4.2%, which in comparison was more than four times higher than non-LGBTQ+ youth. LGBTQ+ youth 19-22 years old were at a significantly higher risk of attempting suicide than non-LGBTQ+ youth. The most common method of attempted suicide was cutting of the wrist, followed by jumping from a high height. There were some common suicide risk factors that were similar between LGBTQ+ and non-LGBTQ+ youth, such as living in a rural area, having a history of a psychiatric disorder, and having a history of non-fatal self-injurious behaviors. The associated increased risk factors for LGBTQ+ youth were having a higher score for CTQ-emotional abuse and CTQ-sexual abuse.

LIMITATION

The causality of risk factors to attempted suicide cannot be assumed due to the cross-sectional nature of the survey. Also, due to the relatively small sample size within the subgroups, we did not assess LGBTQ+ youth separately according to the different sexuality groups.

CONCLUSION

LGBTQ+ youth showed a higher prevalence of attempted suicide when compared to their heterosexual peers. Emotional and sexual abuse showed higher rates among LGBTQ+ youth, the cumulative effects of childhood trauma might explain the difficulties in developing healthy coping styles.

Preoperative body-related emotional distress and culture as predictors of outcomes of bariatric surgery

PURPOSE

Findings concerning the impact of bariatric surgical intervention on both psychological variables and weight loss are often controversial and misconstrued the world over. The aim of this study was to classify bariatric surgery patients according to patterns of preoperative measures that may predict postoperative psychological and physiological outcomes and to compare these patterns between two distinct cultures.

METHODS

Of 169 consecutive bariatric surgery candidates from Israel and 81 candidates from the United States, 73 and 35 patients, respectively consented to be included in a follow-up phase. Body image dissatisfaction, emotional eating behaviors, risk of suicide, depressive symptoms, anxious symptoms, and percent excess weight loss were measured. K-means clustering procedure was used to classify bariatric surgery patients according to their preoperative body-related emotional distress, which was composed of body image dissatisfaction and emotional eating. The joint effect of culture and body-related emotional distress cluster on psychological distress was tested.

RESULTS

The cluster analysis revealed two preoperative body-related emotional distress patterns: high body-related emotional distress and low body-related emotional distress. Following surgery, US patients showed a higher risk of suicide and lower excess weight loss than Israeli patients within only the high body-related emotional distress cluster (a significant interaction effect).

CONCLUSION

Preoperative assessment of body-related emotional distress patterns among bariatric surgery candidates may enable professionals to identify potential postoperative risks of suicide, anxiety, and decreased weight loss. The relationship between the body-related emotional distress cluster and outcome measures is culture dependent.

LEVEL III

Case-control analytic study.

Suicidality risk among adults with binge-eating disorder

OBJECTIVE

To estimate relative suicidality risk associated with binge-eating disorder (BED).

METHODS

Retrospective study of patients identified as having BED (N = 1042) and a matched general population cohort (N = 10,420) from the Optum electronic health record database between January 2009 and September 2015. Patients had ≥1 outpatient encounter with a provider who recognized BED during the 12-month baseline preceding entry date. Incidence and relative risk of suicidality were assessed.

RESULTS

Incidence per 1000 person-years (95% CI) of suicidal ideation and suicide attempts, respectively, was 31.1 (23.1, 41.0) and 12.7 (7.9, 19.4) in the BED cohort and 5.8 (4.7, 7.1) and 1.4 (0.9, 2.2) in the comparator cohort. Risk of suicidal ideation and suicide attempts was greater in the BED cohort (HR [95% CIs], 6.43 [4.42, 9.37]) than in the comparator cohort (HR [95% CI], 9.47 [4.99, 17.98]) during follow-up. After adjusting for psychiatric comorbidities, associations of suicidal ideation and suicide attempts with BED remained elevated in patients with BED having histories of suicidality.

CONCLUSIONS

Findings suggest that history of suicidality may result in an increased risk of suicidal ideation and suicide attempts in patients with BED relative to the general population. Psychiatric comorbidity burden may explain the elevated risk of these conditions in BED.

Body mass index, subjective body shape, and suicidal ideation among community-dwelling Korean adults

Background

Previous studies have not investigated in depth the combination of objective body weight and subjective body shape and its association with suicidal ideation among different age groups. Therefore, this study aimed to examine the abovementioned association among Korean adults, stratified by developmental stages.

Methods

We used nationally representative data from the 2017 Korean Community Health Survey, and included 222,037 participants aged 19 years or older in our study. Suicidal ideation was considered as the dependent variable (1 = yes, 0 = no). Along with body mass index (BMI) and subjective body shape measures, seven categories were created (1 = underweight-skinny, 2 = underweight-normal/fat, 3 = healthy weight-skinny, 4 = healthy weight-normal, 5 = healthy weight-fat, 6 = overweight-skinny/normal, 7 = overweight-fat). Multivariate logistic regression was conducted for each age group.

Results

Adjusted for covariates, young adults who were overweight-fat (OR = 1.18, p < .01), middle-aged adults who were underweight-skinny (OR = 1.32, p < .05), and older adults who were healthy weight-fat (OR = 1.19, p < .05) were more likely to have suicidal ideation than their healthy weight-normal counterparts.

Conclusions

The results suggest that the association between the combination of objective body weight and subjective body shape and suicidal ideation differs according to the developmental stage. Therefore, this difference should be considered when developing suicide prevention interventions based on the developmental stages.

How Is the Suicide Ideation in the Korean Armed Forces Affected by Mental Illness, Traumatic Events, and Social Support?

BACKGROUND

Suicide is one of the leading causes of death in the military as in the general population. To mitigate such a serious public health problem, identifying the risk or protective factors of suicide behaviors is crucial.

METHODS

We analyzed the representative data of the 2014 Korean Armed Forces to explore the relationship between past year adverse events (PAE), accumulated lifetime trauma (ALT), mental illness vulnerability, perceived social support, and suicidal ideation in the previous year.

RESULTS

Among the 6,377 subjects, 3.7% of males and 6.2% of females reported suicidal ideation in the previous year. Multivariate analytic models identified significant associations of PAE and ALT with suicidal ideation with a dose-response pattern. The mental illness vulnerability showed the most significant association with suicidal ideation even after controlling PAE or ALT. We found that perceived social support may be potentially linked with a reduced risk of suicidal ideation.

CONCLUSION

This Korean military representative data demonstrates mental illness vulnerability; PAE; and lifetime trauma as significant risk factors of suicidal ideation, while perceived social support was found as a potential protective factor. Given the importance of the prevention of suicide in the military, those risk and protective factors may be used to screen soldiers at risk of suicide and provide further support on mental health services as needed.

Psychosocial Factors Associated with Suicidal Ideation Among HIV/AIDS Patients on Follow-Up at Dessie Referral Hospital, Northeast Ethiopia: A Cross-Sectional Study

Background

Psychosocial and mental health problems are common among HIV/AIDS patients that affect sustained utilization of healthcare services. To date, information is scarce regarding the perceived stigma, level of social support, and suicidal ideation among HIV/AIDS patients in the study setting. Therefore, this study aimed to assess psychosocial factors associated with suicidal ideation among HIV/AIDS patients on follow-up in the study setting.

Methods

A hospital-based cross-sectional study was conducted among people living with HIV/AIDS (PLWH) on antiretroviral therapy follow-up for at least six months at a referral hospital in northeastern Ethiopia from November to January 2019. A total of 395 study participants of antiretroviral therapy clinic visitors were selected systematically. A binary logistic regression model was fitted to identify factors associated with suicidal ideation among PLWH. An adjusted odds ratio (AOR) with 95% confidence interval (CI) and variables having less than or equal 0.05 p-value used to declare statistical significant association.

Results

This study revealed that 45.3%, 56.5%, and 20%, had perceived stigma, poor social support, and depression, respectively. Moreover, the prevalence of suicidal ideation was 9.4% (95% CI: 6.7 to 12.7) of which, 3.3% had attempted to kill themselves. Low body mass index (AOR=4.11, 95% CI: 1.70 9.91), stages three and above illnesses (AOR=6.63, 95% CI: 1.30 33.79), depression (AOR=4.67, 95% CI: 4.67, 95% CI: 1.75 3.93), poor social support (AOR=4.18, 95% CI: 1.46 11.94), and fair and poor adherence (AOR=3.51, 95% CI: 1.14 10.85) were factors associated with suicidal ideation among PLWH.

Conclusion

This study showed that mental disorders and psychosocial problems were common among PLWH. The poor social support, depression, low body mass index, and poor adherence to ART medications were factors associated with suicidal ideation. This finding underscores the importance of regular screening for common mental health disorders and the strengthening of counseling services, nutritional, and psychosocial support programs.

A comparison of models with weight, height, and BMI as predictors of mortality

Introduction

Body mass index (BMI) is a composite variable of weight and height, often used as a predictor of health outcomes, including mortality. The main purpose of combining weight and height in one variable is to obtain a measure of obesity independent of height. It is however unclear how accurate BMI is as a predictor of mortality compared with models including both weight and height or a weight × height interaction as predictors.

Methods

The current study used conscription data on weight, height, and BMI of Swedish men (N = 48,904) in 1969/70 as well as linked data on mortality (3442 deaths) between 1969 and 2008. Cox proportional hazard models including combinations of weight, height, and BMI at conscription as predictors of subsequent all-cause and cause-specific mortality were fitted to data.

Results

An increase by one standard deviation on weight and BMI were associated with an increase in hazard for all-cause mortality by 5.4% and 11.5%, respectively, while an increase by one standard deviation on height was associated with a decrease in hazard for all-cause mortality by 9.4%. The best-fitting model indicated lowest predicted all-cause mortality for those who weighed 60.5 kg at conscription, regardless of height. Further analyses of cause-specific mortality suggest that this weight seems to be a compromise between lower optimal weights to avoid cancer and CVD mortality and a higher optimal weight to not die by suicide.

Conclusions

According to the present findings, there are several ways to make better use of measured weight and height than to calculate BMI when predicting mortality.

Association of macro-level determinants with adolescent overweight and suicidal ideation with planning: A cross-sectional study of 21 Latin American and Caribbean Countries

BACKGROUND

Adolescents and young people (10-24 years old) in the Latin America and the Caribbean (LAC) region represent approximately 25% of the region's population. Since the 2008 global economic crisis, the pace of reduction in poverty and income inequality in the LAC region has stalled. The region is characterised by high levels of inequities and is also vulnerable to many natural disasters. Food systems are changing with increased availability and marketing of packaged and fast foods and sugar-sweetened drinks. Adolescence is a formative phase of the life course with multiple physical, emotional and social changes which can make them vulnerable to health problems. We assess the potential impact of macro-determinants, human and economic development as well as income inequality, on 2 top-ranking regional priorities for adolescent nutrition and mental health, using measures of overweight and suicidal ideation and planning which some have shown to be associated.

METHODS AND FINDINGS

The Global School-based Health Survey (GSHS) is a nationally representative self-administered, school-based survey. We examined overweight/obesity and suicidal ideation with planning by gross domestic product (GDP) per capita or human development index (HDI) in 10-19-year-old adolescents from 21 LAC countries between 2009 and 2013. Sample sizes varied from 943 in Anguilla to 27,988 in Argentina. A total of 55,295 adolescents had a measure of overweight/obesity status, and 59,061 adolescents reported about suicidal ideation with planning. There was equal representation by sex in the surveys (52% girls and 48% boys). A total of 28.8% of boys and 28.1% of girls had overweight/obesity, and 7.5% of boys and 17.5% of girls reported suicidal ideation with planning over the last 12 months. Adjusted for individual socioeconomic and risk behaviours, and relative to the highest GDP per capita tertile, the middle tertile was associated with 42% (95% confidence interval (CI) 59% to 17%, p = 0.003) and 32% (95% CI 60% to 5%, p = 0.023), and the lowest tertile with 40% (95% CI 55% to 19%, p = 0.001) and 46% (95% CI 59% to 29%, p < 0.001) lower chances of overweight/obesity for girls and boys, respectively. A similar positive effect was seen with HDI, with lowest chances of overweight in the lowest tertile compared with the highest tertile for both sexes. Overweight/obesity was positively related with suicidal ideation with planning for girls (odds ratio (OR) 1.12, 95% CI 1.02 to 1.22, p = 0.009) and weakly related for boys (OR 1.09, 95% CI 0.96 to 1.24, p = 0.182). In contrast to overweight/obesity status, suicidal ideation with planning was not related to macro-level indices despite both outcomes sharing common individual socioeconomic and risk behaviour correlates. Limitations include the dominance of Argentinians in the sample (40%), the exclusion of vulnerable adolescents who dropped out of school, and reporting bias due to stigma of mental health-related issues.

CONCLUSIONS

This study shows that economic and human development were positively associated with adolescent overweight/obesity but not with suicidal ideation with planning. We also observed an interconnectedness between overweight/obesity and suicide ideation with planning among girls. These findings highlight the importance of strategies that engage with both upstream and downstream determinants to improve adolescent nutrition and mental health.

Thigh Circumference and Risk of All-Cause, Cardiovascular and Cerebrovascular Mortality: A Cohort Study

Purpose

The relationship between thigh circumference and all-cause and cause-specific mortality has not been consistent. We aimed to examine how thigh circumference associates with all-cause, cardiovascular, and cerebrovascular mortality among US adults.

Patients and Methods

This cohort study included 19,885 US adults who participated in the 1999–2006 National Health and Nutrition Examination Survey (NHANES) with thigh circumference being measured at baseline, and survival status was ascertained until 31 December 2015. We used Cox proportional hazards models to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for mortality according to thigh circumference in quartiles. Kaplan–Meier survival curve and restricted cubic spline regression were performed to evaluate the prospective association. Finally, subgroup analyses by age, gender, body mass index (BMI), and medical history at baseline were conducted.

Results

During a median follow-up of 11.9 years, 3513 cases of death, 432 death cases due to cardiovascular disease, and 143 death cases due to cerebrovascular disease have occurred. Multivariate Cox regression indicated that every 1cm increase in thigh circumference was related to 4% and 6% decreased risk of all-cause mortality and cardiovascular mortality, respectively. Compared to the reference group, the highest quartile of thigh circumference significantly decreased all-cause mortality by 21% (HR 0.79, 95% CI 0.62–1.00, P<0.05). However, the association of thigh circumference with cerebrovascular mortality was not significant. BMI was a significant effect modifier among individuals with a BMI of less than 25 kg/m² (P<0.0001).

Conclusion

A low thigh circumference appears to be associated with increased risk of all-cause and cardiovascular mortality, but not cerebrovascular mortality.

Studying individual risk factors for self-harm in the UK Biobank: A polygenic scoring and Mendelian randomisation study

BACKGROUND

Identifying causal risk factors for self-harm is essential to inform preventive interventions. Epidemiological studies have identified risk factors associated with self-harm, but these associations can be subject to confounding. By implementing genetically informed methods to better account for confounding, this study aimed to better identify plausible causal risk factors for self-harm.

METHODS AND FINDINGS

Using summary statistics from 24 genome-wide association studies (GWASs) comprising 16,067 to 322,154 individuals, polygenic scores (PSs) were generated to index 24 possible individual risk factors for self-harm (i.e., mental health vulnerabilities, substance use, cognitive traits, personality traits, and physical traits) among a subset of UK Biobank participants (N = 125,925, 56.2% female) who completed an online mental health questionnaire in the period from 13 July 2016 to 27 July 2017. In total, 5,520 (4.4%) of these participants reported having self-harmed in their lifetime. In binomial regression models, PSs indexing 6 risk factors (major depressive disorder [MDD], attention deficit/hyperactivity disorder [ADHD], bipolar disorder, schizophrenia, alcohol dependence disorder, and lifetime cannabis use) predicted self-harm, with effect sizes ranging from odds ratio (OR) = 1.05 (95% CI 1.02 to 1.07, q = 0.008) for lifetime cannabis use to OR = 1.20 (95% CI 1.16 to 1.23, q = 1.33 × 10-35) for MDD. No systematic differences emerged between suicidal and non-suicidal self-harm. To further probe causal relationships, two-sample Mendelian randomisation (MR) analyses were conducted, with MDD, ADHD, and schizophrenia emerging as the most plausible causal risk factors for self-harm. The genetic liabilities for MDD and schizophrenia were associated with self-harm independently of diagnosis and medication. Main limitations include the lack of representativeness of the UK Biobank sample, that self-harm was self-reported, and the limited power of some of the included GWASs, potentially leading to possible type II error.

CONCLUSIONS

In addition to confirming the role of MDD, we demonstrate that ADHD and schizophrenia likely play a role in the aetiology of self-harm using multivariate genetic designs for causal inference. Among the many individual risk factors we simultaneously considered, our findings suggest that systematic detection and treatment of core psychiatric symptoms, including psychotic and impulsivity symptoms, may be beneficial among people at risk for self-harm.

Epidemiological Study and Cost Analysis of Suicide in Spain: Over 100 Years of Evolution

OBJECTIVE

Society has changed during the last 100 years of evolution; however, some problems, such as suicide, remain. The objective here is to carry out a long-term epidemiological study in Spain, and to calculate the social and labor costs of 2016.

METHOD

Epidemiological data were obtained from official data obtained between 1906 - 2016. The calculation of the costs of suicides included the social costs and the costs of production losses (labor costs). The latter were obtained by the human capital method, taking into account the unemployment rate. The economic growth rate stood at 2.6% per year.

RESULTS

The suicide rate was between 4 and 8% per year. The evolution during these 100 years had three periods. Until 1940 it had slight increases, and then it decreased until 1980 and, subsequently, the rate increased until it reached almost 8% in 2016. The costs of the suicides were 2,167 million € of economic losses for society, or its equivalent of 607 € for suicide.

CONCLUSIONS

Public health policies aimed at the prevention of suicide should be increased, and supported by the economic costs they mean for society.

Body mass index weight categories in adults who died by suicide: An observational study

BACKGROUND

There is conflicting evidence about the relationship between body mass index (BMI) and suicide death. This study aimed to characterize and compare suicide deaths by weight using BMI weight categories.

METHODS

We examined suicide deaths in adults in the city of Toronto (2009-2015); grouped them by BMI categories (underweight, normal weight, overweight, and obese) and compared groups based on demographics, clinical variables and method of suicide death.

RESULTS

Suicide decedents' (n = 1429) mean age was 48.6 years (SD = 17.4) and mean BMI was 25.5 (SD = 5.4). Underweight decedents were more likely to be female and to have cancer while obese decedents were more likely to have diabetes. Underweight decedents were more likely to have an identified history of any medical condition. Obese and overweight decedents were significantly more likely to have an identified history of any psychiatric condition. Non-violent methods (e.g., self-poisoning) were used at a higher proportion by people with obesity and by people who were underweight.

LIMITATIONS

Psychological autopsies were not available and it was not possible to assess for change in or stability of BMI over time.

CONCLUSIONS

These findings add to our understanding of the relationship between suicide and weight. A higher prevalence of females as well as those with a history of cancer and any medical condition in underweight decedents was noteworthy and of potential clinical significance.

Body mass index in midlife and risk of attempted suicide and suicide: prospective study of 1 million UK women

BACKGROUND

High body mass index (BMI) has been associated with lower risks of suicidal behaviour and being underweight with increased risks. However, evidence is inconsistent and sparse, particularly for women. We aim to study this relationship in a large cohort of UK women.

METHODS

In total 1.2 million women, mean age 56 (s.d. 5) years, without prior suicide attempts or other major illness, recruited in 1996-2001 were followed by record linkage to national hospital admission and death databases. Cox regression yielded relative risks (RRs) and 95% confidence intervals (CIs) for attempted suicide and suicide by BMI, adjusted for baseline lifestyle factors and self-reported treatment for depression or anxiety.

RESULTS

After 16 (s.d. 3) years of follow-up, 4930 women attempted suicide and 642 died by suicide. The small proportion (4%) with BMI <20 kg/m2 were at clearly greater risk of attempted suicide (RR = 1.38, 95% CI 1.23-1.56) and suicide (RR = 2.10, 1.59-2.78) than women of BMI 20-24.9 kg/m2; p < 0.0001 for both comparisons. Small body size at 10 and 20 years old was also associated with increased risks. Half the cohort had BMIs >25 kg/m2 and, while risks were somewhat lower than for BMI 20-24.9 kg/m2 (attempted suicide RR = 0.91, 0.86-0.96; p = 0.001; suicide RR = 0.79, 0.67-0.93; p = 0.006), the reductions in risk were not strongly related to level of BMI.

CONCLUSIONS

Being underweight is associated with a definite increase in the risk of suicidal behaviour, particularly death by suicide. Residual confounding cannot be excluded for the small and inconsistent decreased risk of suicidal behaviour associated with being overweight or obese.

Does perceived overweight increase risk of depressive symptoms and suicidality beyond objective weight status? A systematic review and meta-analysis

Obesity is associated with a significant disease burden, but whether recognising as opposed to failing to recognise personal overweight is beneficial or detrimental to mental health is unclear. Here we examine the associations between perceived overweight and depressive symptoms and suicidality. A systematic search of three electronic databases yielded 10,398 unique records, from which 32 studies (110 observations) were eligible for inclusion. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated for each outcome using random effects meta-analyses and potential publication bias was examined. Perceived overweight was associated with an increased risk of depressive symptoms (OR: 1.42, CI: 1.31, 1.54 p <.0001, N >128,585) and suicidality (OR: 1.41, CI: 1.28, 1.56, p <.0001, N = 133,576) in both cross-sectional and longitudinal studies. The association between perceived overweight and poorer mental health was observed irrespective of study origin, participant age (children vs. adults), gender, and whether or not a person was objectively overweight. The pooled statistical relationship between objective weight status and poorer mental health was attenuated to non-significance when perceived overweight was accounted for, suggesting that the detrimental effect of overweight on mental health is largely dependent on whether or not a person identifies as overweight.

Body mass index and all cause mortality in HUNT and UK Biobank studies: linear and non-linear mendelian randomisation analyses

EDITOR'S NOTE

Please see the Editor's Note (doi: https://doi.org/10.1136/bmj.l1042) on Methodological Criticism and an Updated Analysis

OBJECTIVE

To investigate the shape of the causal relation between body mass index (BMI) and mortality.

DESIGN

Linear and non-linear mendelian randomisation analyses.

SETTING

Nord-Trøndelag Health (HUNT) Study (Norway) and UK Biobank (United Kingdom).

PARTICIPANTS

Middle to early late aged participants of European descent: 56 150 from the HUNT Study and 366 385 from UK Biobank.

MAIN OUTCOME MEASURES

All cause and cause specific (cardiovascular, cancer, and non-cardiovascular non-cancer) mortality.

RESULTS

12 015 and 10 344 participants died during a median of 18.5 and 7.0 years of follow-up in the HUNT Study and UK Biobank, respectively. Linear mendelian randomisation analyses indicated an overall positive association between genetically predicted BMI and the risk of all cause mortality. An increase of 1 unit in genetically predicted BMI led to a 5% (95% confidence interval 1% to 8%) higher risk of mortality in overweight participants (BMI 25.0-29.9) and a 9% (4% to 14%) higher risk of mortality in obese participants (BMI ≥30.0) but a 34% (16% to 48%) lower risk in underweight (BMI <18.5) and a 14% (-1% to 27%) lower risk in low normal weight participants (BMI 18.5-19.9). Non-linear mendelian randomisation indicated a J shaped relation between genetically predicted BMI and the risk of all cause mortality, with the lowest risk at a BMI of around 22-25 for the overall sample. Subgroup analyses by smoking status, however, suggested an always-increasing relation of BMI with mortality in never smokers and a J shaped relation in ever smokers.

CONCLUSIONS

The previously observed J shaped relation between BMI and risk of all cause mortality appears to have a causal basis, but subgroup analyses by smoking status revealed that the BMI-mortality relation is likely comprised of at least two distinct curves, rather than one J shaped relation. An increased risk of mortality for being underweight was only evident in ever smokers.

Perceived Body Discrimination and Intentional Self-Harm and Suicidal Behavior in Adolescence

BACKGROUND

This study examines whether discrimination based on the body is associated with intentional self-harm and suicidal behavior in adolescence.

METHODS

Participants were from the Longitudinal Study of Australian Children (N = 2948; 48% female). Discrimination and items on self-harm and suicidal behavior were measured in the Wave 6 assessment, when study participants were 14-15 years old. BMI, depressive symptoms, peer victimization, and weight self-perception were also assessed.

RESULTS

Discrimination was associated with increased risk of thoughts of self-harm (OR = 2.41, 95% CI = 1.88-3.10), hurting the self on purpose (OR = 2.27, 95% CI = 1.67-3.08), considering suicide (OR = 2.17, 95% CI = 1.59-2.96), having a suicide plan (OR = 2.50, 95% CI = 1.81-2.47), attempting suicide (OR = 1.96, 95% CI = 1.30-2.96), controlling for sociodemographic factors, BMI, and depressive symptoms. These associations generally held adjusting for peer victimization or weight self-perception.

CONCLUSIONS

Weight discrimination has been associated consistently with poor outcomes in adulthood. The present research indicates these associations extend to adolescence and an extremely consequential outcome: the social experience of weight increases risk of intentional self-harm and suicidal behavior.

Lifestyle Interventions and Prevention of Suicide

Over the past years, there has been a growing interest in the association between lifestyle psychosocial interventions, severe mental illness, and suicide risk. Patients with severe mental disorders have higher mortality rates, poor health states, and higher suicide risk compared to the general population. Lifestyle behaviors are amenable to change through the adoption of specific psychosocial interventions, and several approaches have been promoted. The current article provides a comprehensive review of the literature on lifestyle interventions, mental health, and suicide risk in the general population and in patients with psychiatric disorders. For this purpose, we investigated lifestyle behaviors and lifestyle interventions in three different age groups: adolescents, young adults, and the elderly. Several lifestyle behaviors including cigarette smoking, alcohol use, and sedentary lifestyle are associated with suicide risk in all age groups. In adolescents, growing attention has emerged on the association between suicide risk and internet addiction, cyberbullying and scholastic and family difficulties. In adults, psychiatric symptoms, substance and alcohol abuse, weight, and occupational difficulties seems to have a significant role in suicide risk. Finally, in the elderly, the presence of an organic disease and poor social support are associated with an increased risk of suicide attempt. Several factors may explain the association between lifestyle behaviors and suicide. First, many studies have reported that some lifestyle behaviors and its consequences (sedentary lifestyle, cigarette smoking underweight, obesity) are associated with cardiometabolic risk factors and with poor mental health. Second, several lifestyle behaviors may encourage social isolation, limiting the development of social networks, and remove individuals from social interactions; increasing their risk of mental health problems and suicide.

Body mass index and risk of suicide: A systematic review and meta-analysis

BACKGROUND

Studies have examined associations between obesity and suicide. However, the overall outcomes of the studies are not fully elucidated, and the orientation of these studies needs to be identified. The aim of this systematic review and meta-analysis was to determine the suicide risk based on body mass index (BMI).

METHODS

The authors systematically searched PubMed, Scopus, PsycInfo and Google Scholar databases until December 2017. After the screening process, 15 prospective studies were included in meta-analysis. Stata-14 was used for meta-analysis. Forest Plot was calculated for the whole of the 15 studies and the subgroups; publication bias was examined as well.

RESULTS

In obesity group, Pooled Risk Ratio (RR) was achieved for suicide mortality (RR = 0.67; 95% confidence interval (CI) CI = 0.54-0.81) and suicidal ideation (RR = 1.50; 95% CI = 0.76-2.23). It was also measured in overweight group, for suicide mortality (RR = 0.78; 95% CI = 0.71-0.85) and suicidal ideation (RR = 1.17; 95% CI = 0.65-1.69).

CONCLUSION

Overall, there is an inverse association between obesity and overweight with suicide mortality and attempted suicide, and positive association between obesity and overweight with suicidal ideation. There was no evidence of publication bias. Overall, our findings indicate the role of BMI in suicide.

The relationship between body mass index, binge eating disorder and suicidality

BACKGROUND

While restrictive and compensatory eating disorders (e.g. anorexia and bulimia) are associated with elevated risk of suicide, less is known about binge eating disorder (BED). There is suggestive evidence of a U-shaped relationship between body mass index (BMI) and completed suicide, but fewer studies on suicidal ideation or attempts. This study examined the association between BED, BMI, and suicidality, and assessed whether these relationships varied by gender.

METHODS

Data come from the Collaborative Psychiatric Epidemiologic Surveys (N = 14,497). Binge episodes and BED were assessed using the Composite International Diagnostic Inventory (CIDI). BMI was calculated from self-reported height and weight. Suicidal ideation/attempts were assessed using the CIDI. Weighted logistic regression was used to assess the association between binging/BED, BMI and suicidality. Interaction terms were used to assess whether the relationship between BMI and suicidality was moderated by binging/BED, and whether the relationships between binging/BED and BMI differed by gender.

RESULTS

One-third of adults with BED had a history of suicidality, compared to 19% of those without. Both binging (OR: 1.95, 95% CI: 1.50-2.53) and BED (OR: 2.01, 95% CI: 1.41-2.86) were associated with suicidality in fully-adjusted models. BMI was associated with suicidality in a curvilinear manner, and this relationship was exacerbated by binging/BED (OR_{Binge eating x BMI}: 1.04, 95% CI: 1.01-1.09, p < 0.05). The relationship between BMI and suicidality did not differ by gender (OR_{gender x BMI}: 1.00, p < 0.770). However, the relationship between binge eating and suicidality was stronger for women relative to men (OR_{gender X binge}: 1.87, p < 0.012).

CONCLUSIONS

Binge eating, even below the threshold for BED, is associated with suicidality. BMI is associated with suicidality in a curvilinear manner, and the BMI-suicidality relationship is potentiated by binge eating/BED. Findings support the thoughtful integration of psychiatric care into weight loss programs for adults with a history of binging behavior.

The association between cannabis use and suicidal behavior in patients with psychiatric disorders: an analysis of sex differences

BACKGROUND

Cannabis is the most commonly used illicit drug. In the general population, its use has been linked to a heightened propensity for suicidal behavior (SB). We hypothesize that this association varies in patients with psychiatric disorders. SB is known to vary by sex and therefore an investigation of cannabis' association with SB must consider sex differences. The purpose of this study is to investigate the association between cannabis use and suicide attempts in men and women with psychiatric disorders.

METHODS

We merged data collected for two studies based in Ontario, Canada (n = 985). We employed a multivariable logistic regression to assess the association between cannabis use and suicide attempts in men and women with psychiatric disorders.

RESULTS

We analyzed data from 465 men and 444 women. Amongst these, 112 men and 158 women had attempted suicide. The average age of our participants was 40 years (standard deviation (SD) 12.4). We found no significant association between suicide attempts and cannabis use in men (odds ratio (OR) = 1.34, 95% confidence interval (CI) 0.81, 2.22, p = 0.260) or women (OR = 0.97, 95% CI 0.61, 1.54, p = 0.884). In a sensitivity analysis using a sample of patients with substance use disorder only, the heaviness of cannabis use was associated with small but significant association with SB in men (OR = 1.03, 95% CI 1.01, 1.05, p = 0.007).

CONCLUSION

Our findings indicate that there is no association between cannabis use and suicidal behavior in men or women with psychiatric disorders unlike what was reported for the general population, though the heaviness of cannabis use may have an effect in men. The impact of cannabis use in psychiatric disorders needs ongoing examination in light of its common use, impending legalization with expected increased access and the uncertainty about cannabis' effects on prognosis of psychiatric disorders. In addition, research should continue to investigate modifiable risk factors of SB in this population of which cannabis is not a significant factor based on this study.

The androgen model of suicide completion

Suicide is a devastating public health issue that imposes severe psychological, social, and economic burdens not only for the individuals but also for their relatives, friends, clinicians, and the general public. Among the different suicidal behaviors, suicide completion is the worst and the most relevant outcome. The knowledge of biological etiopathological mechanisms involved in suicide completion is limited. Hitherto, no objective markers, either alone or in combination, can reliably predict who will complete a suicide. However, such parameters are strongly needed to establish and optimize prediction and prevention. We introduce here a novel ideation-to-completion framework in suicide research and discuss the problems of studies aiming at identifying and validating clinically useful markers. The male gender is a specific risk factor for suicide, which suggests that androgen effects are implicated in the transition from suicidal ideation to suicide completion. We present multiple lines of direct and indirect evidence showing that both an increased prenatal androgen load (with subsequent permanent neuroadaptations) and increased adult androgen activity are involved in suicide completion. We also review data arguing that modifiable maternal behavioral traits during pregnancy contribute to the offspring's prenatal androgen load and increase the risk for suicide completion later in life. We conclude that in utero androgen exposure and adult androgen levels facilitate suicide completion in an synergistic manner. The androgen model of suicide completion provides the basis for the development of novel predictive and preventive strategies in the future.

Clinical epidemiology of long-term suicide risk in a nationwide population-based cohort study in South Korea

We investigated the effects of a large range of clinical factors on the long-term risk of suicide in the general population of South Korea. We analyzed the National Health Insurance Service-National Sample Cohort (NHIS-NSC) database in South Korea. A total of 300,232 individuals were followed for up to 12 years. We obtained information on demographic variables (age and sex), lifestyle variables (cigarette smoking, alcohol drinking and exercise), psychiatric and physical disorders, laboratory examination results and physical examination findings. We conducted a competing risk survival analysis to estimate the risk of completed suicide. 725 individuals (241/100,000) died by suicide in the follow-up period. After Bonferroni correction, we found a significant suicide risk associated with 6 variables: Parkinson's disease, depressive disorder, obsessive-compulsive disorder (inverted association), elevated serum aspartate aminotransferase levels, male gender and age. Before Bonferroni correction, variables such as cigarette smoking, heavy alcohol drinking, psychotic disorder, other psychiatric disorder, benzodiazepine use and higher fasting glucose showed some significant association. In addition, body mass index and height were inversely related to completed suicide before Bonferroni correction. However, only the 6 variables listed above were robust predictors of suicide in the fully adjusted analyses with multiple test correction. Common medical conditions had no clear influence on suicide. Diverse clinical factors influenced the long-term risk of completed suicide in this general population sample. Comprehensive assessment of these risk factors will facilitate more focused suicide surveillance measures.

Association between body mass index and suicidal ideation among seniors in Shandong, China

BACKGROUND

Recently, an emerging group of studies has reported the association between Body Mass Index (BMI) and suicidal ideation in the Western countries. However, this relationship is still unclear with controversial results, and we have little knowledge about this relationship in China which is one of few countries reported higher suicide rates.

METHODS

This study aims to analyze the association between BMI and suicidal ideation among seniors (≥60 years old) in Shandong, China. A total of 3313 seniors were included in the data analysis. Suicidal ideation, weight, height, socio-demographic and psychological variables were evaluated in this study. Logistic regression was conducted to explore the association between BMI and suicidal ideation among male and female seniors.

RESULTS

The results showed that 4.2% of the seniors reported suicidal ideation, and 3.4% for men, 4.9% for women. After controlling social-demographic variables, economic status, physical disease, social support and mental health, an inverse relationship between BMI and suicidal ideation was found for men, but not for women. Mental health was still an important factor associated with suicidal ideation.

CONCLUSION

The results inform health care professors that underweight in male seniors can be associated with higher risk of suicidal ideation in China.

Exploring metabolic factors and health behaviors in relation to suicide attempts: A case-control study

BACKGROUND

Suicide attempts are a serious public health concern with devastating global impact, thereby necessitating the development of an adequate prevention strategy. Few known risk factors of suicide attempts are directly modifiable. This study sought to investigate potential associations between health behaviors and suicide attempts, identifying novel opportunities for clinicians to help prevent suicidal behavior.

METHODS

A case-control study was conducted to compare body weight, serum total cholesterol, physical activity, tobacco use, and dietary food groups among adults who had made a suicide attempt (n = 84) to psychiatric inpatients (n = 104) and community controls (n = 93) without history of suicide attempt. Multivariable binary logistic regression analyses were used to investigate the association between metabolic risk factors and attempted suicide.

RESULTS

Psychiatric inpatients who had attempted suicide were less likely to be physically active [moderate/strenuous (OR 0.42, 95% CI 0.19-0.95) and mild (OR 0.35, 95% CI 0.16-0.76)] compared to controls. Psychiatric inpatients who attempted suicide were more likely to use tobacco (OR 2.25, 95% CI 1.07-4.73) compared to controls. Contrary to prior research, obesity, serum total cholesterol, and diet were not significantly associated with risk of attempted suicide.

LIMITATIONS

Our study was limited by its cross-sectional design, which precludes the identification of causal or temporal relationships between the risk of attempted suicide and factors such as physical activity and tobacco use.

CONCLUSIONS

Study results suggest that a history of attempted suicide is associated with a decreased likelihood of being physically active and an increased risk of tobacco use. Further investigation is warranted to understand the role of exercise and tobacco use in suicide intervention and prevention strategies.

Association of Body Mass Index with Suicide Behaviors, Perceived Stress, and Life Dissatisfaction in the Korean General Population

OBJECTIVE

The purpose of the present study was to investigate the association between Body Mass Index, suicide, perceived stress, and life dissatisfaction in a general population sample of Korean adults.

METHODS

A total of 6,022 nationally representative adults aged 18 to 74 were selected using a multistage cross-sectional cluster sampling method. Questionnaires regarding suicide behaviors, perceived stress, and life satisfaction were completed by the participants. They also reported their heights and weights, which were used to calculate BMI. Psychiatric disorders were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, using the Korean version of the Composite International Diagnostic Interview.

RESULTS

The results showed that being underweight was associated with higher risk for suicide ideation [odds ratio (OR), 1.6; 95% confidence interval (Cl), 1.18-2.05] and suicide attempt (OR, 2.0, 95% Cl, 1.23-3.31). Likewise, obesity also increased the risk of suicide ideation (OR, 1.3; 95% Cl, 1.11-1.56) although not suicide attempt. Furthermore, underweight individuals were more likely to report severe level of perceived stress (OR, 1.7; 95% Cl, 1.26-2.17) and life dissatisfaction (OR, 1.3; 95% Cl, 1.07-1.68). All of the results remained significant after adjusting for age, gender, education, and psychiatric illnesses.

CONCLUSION

This study found that being underweight is a significant risk factor for suicide and poor subjective wellbeing in Korea. It suggests that BMI status may be an important modifiable factor for improving mental health in Korea.

The relative influence of individual risk factors for attempted suicide in patients with bipolar I versus bipolar II disorder

OBJECTIVES

To compare the relative influence (RI) of individual predictors for lifetime attempted suicide between adults with bipolar I (BDBD-I) and bipolar II disorder (BDBD-II).

METHODS

We conducted an analysis of data from 1465 enrollees in the Mayo Clinic Bipolar Disorder Biobank. Demographic and clinical variables and history of attempted suicide were ascertained using standardized questionnaires. Height and weight were assessed to determine body mass index (BMI); obesity was defined as BMI ≥30kg/m². The frequencies of these variables were compared between persons with and without self-reported lifetime suicide attempts both overall, and within BD-I and BD-II subgroups. Gradient boosting machine (GBM) models were used to quantify the RI of study variables on the risk of lifetime attempted suicide.

RESULTS

Nearly one-third of patients reported having a lifetime suicide attempt. Attempted suicide rates were higher in patients with BD-I than BD-II, but absolute differences were small. Lifetime attempted suicide was associated with female sex, BD-I subtype, psychiatric and substance use comorbidities, binge eating behavior, lifetime history of rapid cycling, other indicators of adverse illness course, and early age of bipolar illness onset in the entire cohort. Differences in the rank-ordering of RI for predictors of attempted suicide between BD-I and BD-II patients were modest. Rapid cycling was a strong risk factor for attempted suicide, particularly in men with BD-I.

LIMITATIONS

Actively psychotic or suicidal patients needing psychiatric hospitalization were initially excluded, but were approached after these acute psychiatric problems resolved.

CONCLUSIONS

The prevalence of lifetime attempted suicide was significantly higher in BD-I than BD-II in this large, cross-sectional cohort. Predictors of attempted suicide were similar in BD-I and BD-II subgroups.