Neurobiology of suicidal behaviour

Associations of green and blue space and the natural environment with suicidal ideation: The role of psychiatric disorders

BACKGROUND

Previous research has demonstrated the importance of environmental factors and exposure to the natural environment for human physical and mental health. However, the associations between green space, blue space, and the natural environment (GBN) and the risk of suicidal ideation have not been prospectively studied, and the potential role of psychiatric disorders in these associations has not been explored.

METHODS

Longitudinal data from the UK Biobank was used. At study baseline (2006-2010), 135,901 participants (female: 56.6%; mean age 56.05 ± 7.73 years) were included. A series of binary logistic regression models were used to examine the independent, joint, and interactive associations of GBN and psychiatric disorders with suicidal ideation.

RESULTS

Compared with the first quartile (lowest) of exposure, the natural environment at 300 m buffer [Q2, OR = 0.899, 95% CI: 0.835-0.968; Q3, OR = 0.897, 95% CI: 0.831-0.968] and blue space at 1000 m buffer [Q3, OR = 0.920, 95% CI: 0.853-0.993] were significantly associated with lower risk of suicidal ideation. Green space (the fourth quartile) and the natural environment (the fourth quartile) at 1000 m buffer had 14.5% and 15.2% decreased risk of suicidal ideation, respectively. The lowest risk of suicidal ideation was observed among participants with high levels of GBN and no psychiatric disorders, which may be attributed to significant multiplicative and synergistic interactions.

CONCLUSIONS

Our findings emphasized the significant benefits of GBN exposure in reducing the risk of suicidal ideation, especially in groups with psychiatric disorders. Future research is necessary to conduct to explore potential mechanisms.

Epigenetics and suicidal behavior in adolescents: a critical review

Suicide continues to be a significant public health issue globally, claiming over 700,000 lives annually. It is, therefore, important to assess the suicide risk properly and provide intervention in a timely fashion. While the heritability of suicidal behavior is around 50%, it does not explain the factors involved in causality. Recent evidence suggests that gene x environment interaction plays a vital role in suicidal behavior. In this paper, we critically evaluate the association between adolescent suicidal behavior and epigenetic modifications, including DNA methylation, histone modification, and non-coding RNAs, as well as epigenetic-based treatment options. It was noted that the prevalence of suicidal behavior in adolescents varied by age and sex and the presence of psychiatric disorders. Childhood adversity was closely associated with suicidal behavior. Studies show that alterations in epigenetic modifications may increase the risk of suicidal behavior independent of mental illnesses. Because epigenetic factors are reversible, environmental enrichment or the use of pharmacological agents that can target specific epigenetic modulation may be able to reduce suicidal behavior in this population.

Cognitive control impairment in suicide behaviors: what do we know? A systematic review and meta-analysis of Stroop in suicide behaviors

BACKGROUND

Suicidal behavior results from a complex interplay between stressful events and vulnerability factors, including cognitive deficits. Poorer performance on the Stroop task, a measure of cognitive control, has been associated with suicidal behavior in numerous studies. The objective was to conduct an updated systematic review of the literature on the Stroop task as a neuropsychological test of vulnerability to suicidal acts in patients with mood and other psychiatric disorders, while also looking at how the type (classic versus emotional) or the version (paper or computerized) of the Stroop task, as well as the characteristics of the patient (clinical population, age, sex) moderated the Stroop effect.

METHODS

A search on Medline, Embase, PsycInfo databases, and article references was performed. 53 studies (6781 participants) met the selection criteria. Interference time and errors of the Stroop Test were assessed in at least 3 studies to be analyzed. Moderators, such as the type (classic versus emotional) of the Stroop task and the characteristics of the patient (clinical population, age, sex) were also assessed.

RESULTS

Interference time on Stroop performance was lower in suicide attempters than in patient controls (g = 0.20; 95%CI [0.10-0.30]) and healthy controls (g = 0.79; 95 % CI [0.29-1.29]), with patient controls scoring lower than healthy controls (g = -0.63; 95%CI [-1.01-0.25]). This was moderated by age and having a mood disorder. In terms of interference errors, suicide attempters performed worse than healthy controls (g = 0.57; 95%CI [0.01-1.15]) but did not perform differently from patient controls (g = 0.20; 95 % CI [-0.06-0.45]). Patient controls also did not score differently than healthy controls (g = -0.18; 95 % CI [-0.54-0.18]). There was a significant moderation effect for the type (i.e., original Stroop task) and version (i.e., paper format) of the Stroop task, and for some characteristics of the patient (i.e., older patients and having a mood disorder).

CONCLUSIONS

Cognitive control impairment was associated with a history of suicidal behavior in patients, especially in older populations and those with mood disorders, however this result was moderated by outcome measure (interference time vs. errors), the type (i.e., original Stroop task) and the version (i.e., paper format) of the Stroop task. Cognitive control processes may be an important factor of suicidal vulnerability. Choosing the right neurocognitive test in the right population to detect suicide vulnerability is important direction for future research.

Understanding Suicidal Thoughts and Behaviors Among LGBTQ + Youth: Differential Associations Between Bullying and Substance Use

Rates of suicidal thoughts and behaviors (STB, i.e., suicidal thoughts, plans, and attempts), substance use, and bullying victimization are higher among lesbian, gay, bisexual, transgender, and/or queer (LGBTQ +) youth compared to their heterosexual peers. However, research examining the interactive and potentially compounding associations of concurrent bullying and substance use (alcohol, cannabis, hallucinogens, and opioids) with STB is sparse, especially among LGBTQ + youth. Thus, the current study aims to understand how these substances moderate the association between bullying victimization and STB by utilizing data (N = 96,482) from the combined 2003-2019 Youth Risk Behavior Survey (YRBS). Using a cross-sectional design and hierarchical logistic regression, we found that, on average, LGBTQ + youth who were bullied were more likely to report planning to attempt suicide (O.R. = 2.71, p < .01). Similarly, youth who reported using opioids/prescription drugs (O.R. = 4.60, p < .05) or hallucinogens (O.R. = 8.89, p < .01) were more likely to attempt suicide. No significant associations between alcohol use and STB were found. Lastly, cannabis emerged as a significant moderator of the associations between bullying victimization and suicidal ideation and plans, such that adolescents who were bullied and used cannabis were less likely to report suicidal ideation and planning compared to those who were bullied but did not use cannabis. These findings highlight that different substances are distinctively associated with STB among LGBTQ + youth, providing a better understanding of how individuals who are being bullied may cope and to develop prevention programs to combat suicidal thoughts, planning, and attempts.

Acceptance and commitment therapy reduces perceived ostracism in suicidal patients

INTRODUCTION

Ostracism increases the risk of depression and suicidal behaviors. Mindfulness training, which is at the core of third-wave behavioral therapies such as acceptance and commitment therapy (ACT), might reduce social distress and inhibit negative affect.

METHODS

This randomized controlled trial included 32 patients with a history of suicide attempt in the past year who followed seven weekly sessions of ACT or progressive relaxation therapy (PRT). To assess and compare the effects of ACT and PRT on social distress, patients performed a validated paradigm of social exclusion (the Cyberball Game) followed by completion of the Need Threat Scale (NTS) at inclusion (baseline) and within two weeks after the intervention ended (posttherapy).

RESULTS

The included patients were mainly women (N = 28; 87.5%), and their mean age was 40 years (SD: 12 years). Twenty-six patients (81%) experienced current depression. The postintervention NTS score was greater (lower social distress) in the ACT group than in the PRT group (group × time interaction; β = 0.47, p < 0.05), even after controlling for depressive symptoms (β = 0.27, p < 0.05). The NTS score change (between baseline and posttherapy) was correlated with changes in dispositional mindfulness (r = 0.46, p = 0.03), cognitive fusion (r = - 0.61, p < 10-3) and acceptance (r = 0.57, p < 10-2).

CONCLUSION

ACT decreased social pain independently of its effect on depression. Reduced social pain was correlated with improved therapeutic processes and decreased suicidal ideation, highlighting the therapeutic potential of ACT for managing ostracism and suicide risk.

Suicidal Behaviour Prior to First Episode Psychosis: Wider and More Widespread Grey-Matter Alterations

INTRODUCTION

The prodromal phase preceding the onset of First Episode Psychosis (FEP) is associated with an increased risk of Suicidal Behaviors (SBs). The aim of this study was to identify specific structural brain abnormalities linked to SBs that occur prior to the onset of FEP.

METHODS

Voxel-based morphometry analyses were used to investigate differences in brain Grey Matter (GM) volume using the CAT12 toolbox within SPM12. Covariates, including gender, age, handedness, intracranial volume, depression severity, and global cognitive functioning, were controlled for as confounding factors.

RESULTS

Significant reductions in GM were observed in the left superior temporal gyrus, dorsal posterior cingulate cortex, precuneus, cuneus, anterior cerebellum (p-FWE corrected < 0.05, k > 50) as well as in the right amygdala (0.96 ± 0.06 vs. 1.01 ± 0.05; F = 4.78; p < 0.05) and left amygdala (0.97 ± 0.06 vs. 1.02 ± 0.05; F = 8.97; p = 0.01).

CONCLUSIONS

History of SB prior to the onset of the psychotic disorder was related to wider and more widespread brain GM alterations. The regions identified are involved in cognitive and emotional processes such as emotional regulation, social cognition, perseverative thinking, and pain tolerance. These findings suggest that structural brain abnormalities related to SB occurring before FEP onset may serve as early biomarkers for identifying individuals at increased risk of suicide.

Neurofilament light chain level is associated with lifetime suicidal behaviors

BACKGROUND

Suicide is among the severe outcomes of mental illness and has been reported to be associated with neurodegeneration and cognitive impairment. The blood neurofilament light chain (NfL) level is a biomarker of neuronal damage in neuropsychiatric disorders. This study investigated whether the NfL levels are associated with lifetime suicidal behaviors and whether this level is higher in patients with major depressive disorder (MDD) compared with healthy controls.

METHODS

In this cross-sectional study, we included 73 patients with MDD and 40 age- and sex-matched controls. The blood NfL levels were measured using an enzyme-linked immunosorbent assay. We compared the NfL levels between patients with MDD and controls and performed regression analysis to evaluate the association between the NfL levels and suicidal behaviors.

RESULTS

Nearly half of the patients with MDD (43.80%) reported lifetime suicide attempts. Those with MDD had higher blood NfL levels, but their levels did not significantly differ from those of the healthy controls. Logistic regression results revealed higher risks of lifetime suicide planning (Odds ratio [OR] = 1.64) and suicide attempts (OR = 1.94) with every 10 pg/mL increase in the NfL levels.

CONCLUSIONS

Our results demonstrate that higher serum NfL levels were associated with lifetime suicidal behavior.

Association of peripheral and cerebral inflammatory markers with suicidal deaths in Indian population

Globally, a suicide occurs every 43 seconds. In India, approximately 465 suicides took place daily in 2022, with a suicide rate of 12.4 per 100,000 population, exceeding the global rate of 9. This study aims to investigate differences in cytokine levels, including vascular endothelial growth factor (VEGF), between individuals who died by suicide and those who did not. Additionally, it aims to explore any pattern between plasma and cerebrospinal fluid (CSF) levels of these analytes. Concentrations of inflammatory cytokines, i.e., Interleukins: IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-13, Tumor Necrosis Factor-α and VEGF in plasma and CSF were analyzed among suicide death subjects (N = 6, cases) and non-suicidal death subjects (N = 59, controls). All analytes were quantified using a customized multiplex (9-plex) kit, with 50 µl of plasma and CSF in duplicates. Significantly higher levels of IL-6 (p < 0.001) and IL-10 (p < 0.05) were observed in the plasma of the suicidal group. However, no statistically significant changes were found in the rest of the analytes between the two groups. In CSF, only VEGF levels were significantly lower in the suicidal group (p < 0.01). In cases, significant positive correlations were observed between plasma and CSF levels of IL-1β, IL-4, IL-6, and IL-10, whereas in controls, only IL-8 demonstrated a significant positive correlation, indicating a moderate relationship between these cytokines systemic and central concentrations. Dysregulation of inflammatory biomarkers appears to play a crucial role in the pathophysiology of suicide. We conclude that higher levels of IL-6 are present in the plasma of suicide completers compared to non-suicidal deceased individuals.

Alterations in orbitofrontal cortex communication relate to suicidal attempts in patients with major depressive disorder

BACKGROUND

Investigating how the interaction between the orbitofrontal cortex (OFC) and various brain regions/functional networks in major depressive disorder (MDD) patients with a history of suicide attempt (SA) holds importance for understanding the neurobiology of this population.

METHODS

We employed resting-state functional magnetic resonance imaging (rs-fMRI) to analyze the OFC's functional segregation in 586 healthy individuals. A network analysis framework was then applied to rs-fMRI data from 86 MDD-SA patients and 85 MDD-Control patients, utilizing seed mappings of OFC subregions and a multi-connectivity-indicator strategy involving cross-correlation, total interdependencies, Granger causality, and machine learning.

RESULTS

Four functional subregions of left and right OFC, were designated as seed regions of interest. Relative to the MDD-Control group, the MDD-SA group exhibited enhanced functional connectivity (FC) and attenuated interaction between the OFC and the sensorimotor network, imbalanced communication between the OFC and the default mode network, enhanced FC and interaction between the OFC and the ventral attention network, enhanced interaction between the OFC and the salience network, and attenuated FC between the OFC and the frontoparietal network.

LIMITATIONS

The medication and treatment condition of patients with MDD was not controlled, so the medication effect on the alteration model cannot be affirmed.

CONCLUSION

The findings suggest an imbalanced interaction pattern between the OFC subregions and a set of cognition- and emotion-related functional networks/regions in the MDD-SA group.

Cross-sectional and longitudinal analysis of high-sensitivity C-reactive protein as a biomarker for suicidal behavior in depressive patients undergoing pharmacotherapy

This study investigated the role of serum high-sensitivity C-reactive protein (hsCRP) as a biomarker for suicidal behavior (SB) in both cross-sectional and longitudinal contexts, driven by emerging evidence that systemic inflammation, marked by elevated hsCRP levels, may be linked to increased suicidality in individuals with depressive disorders. Serum hsCRP levels were measured at baseline in 1,094 patients with depressive disorders. Of these, 884 were followed during a 12-month period of stepwise pharmacotherapy. SB assessments included previous suicide attempts and baseline suicidal severity at baseline, and increased suicidal severity and fatal/non-fatal suicide attempts at follow-up. We analyzed the associations between hsCRP levels (and elevated levels ≥1.0 mg/L) with these SB categories using logistic regression, adjusting for relevant covariates. Higher or elevated serum hsCRP levels were significantly associated with SB at baseline in cross-sectional analyses. However, these associations did not persist in the 12-month longitudinal analyses after adjustments. While hsCRP serves as a concurrent biomarker for SB, it does not act as a predictive marker for future suicidal behaviors. Future research should include repeated measures of hsCRP in a controlled setting to confirm these findings.

Altered Functional Connectivity of Prefrontal Cortex-Related Circuitry and Trait Impulsivity in Patients With Bipolar Disorder and History of Suicide Attempts

BACKGROUND

The neurobiological basis of impulsivity and its role in suicide attempt (SA) in BD remains underexplored. This study aimed to examine the functional connectivity (FC) within the prefrontal cortex (PFC) in BD patients with and without a history of SA, focusing on the role of trait impulsivity.

METHODS

Seventy-two euthymic BD patients (34 with a history of SA, BDSA; and 38 without, BDNS) and 55 age- and sex-matched healthy controls underwent resting-state functional MRI. FC analyses were conducted on four PFC regions: superior frontal gyrus (SFG), middle frontal gyrus (MFG), inferior frontal gyrus (IFG), and orbitofrontal cortex (OFC). Trait impulsivity was assessed using the Barratt Impulsiveness Scale (BIS-11), and its association with FC was analyzed using a general linear model, adjusting for demographic and clinical variables.

RESULTS

BDSA had higher trait impulsivity than BDNS and the controls. BDSA exhibited reduced FC between the PFC and sensorimotor (postcentral and precentral gyri) and thalamic regions compared to BDNS. These reductions in FC of the fronto-thalamic and fronto-sensorimotor circuits were significantly associated with higher trait impulsivity scores.

CONCLUSION

The findings highlight specific PFC-based FC alterations associated with suicide attempts and trait impulsivity in BD, offering potential neurobiological markers for suicide risk in this population.

Association and interaction between overweight/obesity and suicide attempts in young first-episode and drug-naïve patients with major depressive disorder

Aims

This research's objective was to explore the correlation of overweight/obesity and suicide attempts in young patients with major depressive disorder (MDD) and the related factors of suicide attempts in patients with/without overweight/obesity.

Methods

This study included 520 young patients with MDD who were first-episode and drug-naïve (FEDN), with an average age of 20.50 ± 2.36 years. Height and weight of each subject were measured, and overweight was classified as 24≤BMI<28, and obesity as BMI≥28.Biochemical indicators were detected including blood glucose, lipid, and thyroid function indicators. Depressive symptoms, anxiety symptoms, and psychotic symptoms were evaluated using Hamilton Rating Scale for Depression (HAMD), Hamilton Anxiety Rating Scale (HAMA) and Positive and Negative Syndrome Scale (PANSS) positive subscale, respectively.

Results

Overweight/obesity was a separate factor influencing suicide attempts in subjects(p < 0.05, OR = 0.57, 95%CI: 0.34-0.95). Higher HAMD, HAMA scores, levels of total cholesterol (TC), thyroid stimulating hormone (TSH), and prevalence of thyroid peroxidase antibody abnormalities were seen in overweight/obese individuals who attempted suicide(all p values < 0.01).While in patients without overweight/obesity, those who attempted suicide had higher HAMD, HAMA, PANSS positive subscale scores, levels of TSH, fasting blood glucose, TC, blood pressure, prevalence of TSH abnormalities, and lower levels of high-density lipoprotein cholesterol(all p values < 0.01).

Conclusions

In young FEDN patients with MDD, overweight/obesity might influence the incidence of suicide attempts and related influences.

A Suicide Attempt Multicomponent Intervention Treatment (SAMIT Program): study protocol for a multicentric randomised controlled trial

BACKGROUND

Suicide has become a first-order public health concern, especially following the negative impact of COVID-19 on the mental health of the general population. Few studies have analysed the effects of early psychotherapeutic interventions on subjects who have attempted suicide, and even fewer have focused on those hospitalized in non-psychiatric units after a Medically Serious Suicide Attempt (MSSA). The main aim of this study is to describe the protocol designed to evaluate the effectiveness of individual psychological treatment for patients hospitalized after an MSSA. The secondary objectives of the study are: (1) to evaluate the impact on quality of life and other psychosocial variables of patients with a recent MSSA who receive early psychological intervention; (2) to analyse the biological, psychological, and clinical impact of early psychotherapeutic treatment on subjects hospitalized after an MSSA.

METHODS

A longitudinal randomised controlled trial will be conducted with patients over 16 years of age admitted to two general hospitals. The case intervention group will enrol for 8-sessions of individual psychotherapy, Suicide Attempts Multi-component Intervention Treatment (SAMIT), combining Dialectical Behaviour Therapy (DBT), Mentalization-Based Therapy (MBT), and Narrative approaches, while the control group will receive a treatment-as-usual intervention (TAU). Longitudinal assessment will be conducted at baseline (before treatment), post-treatment, and 3, 6, and 12 months after. The main outcome variable will be re-attempting suicide during follow-up.

DISCUSSION

Some psychotherapeutic interventions, usually implemented in outpatient, have proven to be effective in preventing suicidal behaviours. The combination of some of these may be a powerful treatment for preventing future SA in patients hospitalised after an MSSA, which is the most severely suicidal subgroup. Moreover, assessment of the biological, clinical and psychometric impact of this new intervention on patients during the first year after the attempt may help understand some of the multi-level factors associated with the effectiveness of psychotherapeutic interventions in MSSAs. The prevalence of high suicide rates requires the design of effective psychological interventions for their prevention, and also in order to design new pharmacological and psychological treatments.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT06238414. Date of registration: 1st February 2024, final update is protocol version 3.0, 19th March 2024.

The forensic aspects of suicide and neurotrophin factors: a research study

Introduction: Suicide represents a significant public health problem whose neurobiology is not yet fully understood. In many cases, suicidal behavior and psychiatric spectrum disorders are linked, in particular, to major depression. An emerging pathophysiological hypothesis underlines the role of neurotrophic factors, proteins involved in neurogenesis, in synaptic plasticity in response to stressors. Our research aims to evaluate the degree of expression of brain neurotrophic factor (BDNF) in brain areas involved in depressive disorder in suicidal subjects. Furthermore, we want to evaluate the expression of glial cell line-derived neurotrophic factor (GDNF) in suicidal subjects. Methods: We selected twenty confirmed cases of suicide among subjects with a clinical history of depressive pathology and possible psychopharmacological treatment, compared to ten controls of individuals who died of non-suicidal causes. For all selected cases and controls, immunohistochemical investigations were performed using a panel of antibodies against the BDNF and GDNF antigens on samples from the various brain areas. Results and discussion: The results show that BDNF was under-expressed in the cerebral parenchyma of subjects who died by suicide compared to controls, while there was an overexpression of GDNF in suicide victims, these data could be useful for a clinical application as potential markers for suicidal risk, to assess the severity of depression and development of specific pharmacological therapies for depression.

The investigation of relationship between serum melatonin levels with Beck Depression Inventory and Beck Scale for Suicidal Ideation in suicide patients

OBJECTIVE

Melatonin plays a role in many biological and physiological events. There are studies in the literature relating melatonin levels to many psychiatric disorders such as schizophrenia, bipolar disorder, and major depressive disorder. We aimed to investigate the relationship between serum melatonin levels with the Beck Depression Inventory and the Beck Scale for Suicidal Ideation in suicide patients.

METHODS

The study was conducted prospectively with volunteer patients aged 20-50 years who were admitted to the emergency department after a suicide attempt. The social and occupational status, educational levels, marital status, and stressor factors of patients were questioned. Beck Depression Inventory and Beck Scale for Suicidal Ideation were applied to each patient included in the study. Blood melatonin levels were evaluated using the enzyme-linked immunosorbent assay method. The data were analyzed with the SPSS 23.00 statistical program. Descriptive values were expressed by the number of cases (n), percentage (%), median (interquartile range), and mean±standard deviation. The Kolmogorov-Smirnov test was used to assess the distribution of continuous variables, and the Pearson or Spearman correlation test was used to assess the relationship between disease severity and melatonin level. A value of p<0.05 was considered statistically significant.

RESULTS

No statistically significant correlation was found between melatonin level and the Beck Depression Inventory score (r=-0.098, p=0.44). However, a statistically weak, inverse, and significant correlation was discovered between melatonin levels and the Beck Scale for Suicidal Ideation score (r=-0.465, p=0.00).

CONCLUSION

According to our results, it was determined that there was a significant negative relationship between melatonin level and the Beck Scale for Suicidal Ideation scoring.

Potential association between suicide risk, aggression, impulsivity, and the somatosensory system

Aggression and impulsivity are linked to suicidal behaviors, but their relationship to the suicidal crisis remains unclear. This magnetoencephalography (MEG) study investigated the link between aggression, impulsivity, and resting-state MEG power and connectivity. Four risk groups were enrolled: high-risk (HR; n = 14), who had a recent suicidal crisis; lower-risk (LR; n = 41), who had a history of suicide attempts but no suicide attempt or ideation in the past year; clinical control (CC; n = 38), who had anxiety/mood disorders but no suicidal history; and minimal risk (MR; n = 28), who had no psychiatric/suicidal history. No difference in resting-state MEG power was observed between the groups. Individuals in the HR group with high self-reported aggression and impulsivity scores had reduced MEG power in regions responsible for sensory/emotion regulation vs. those in the HR group with low scores. The HR group also showed downregulated bidirectional glutamatergic feedback between the precuneus (PRE) and insula (INS) compared to the LR, CC, and MR groups. High self-reported impulsivity was linked to reduced PRE to INS feedback, whereas high risk-taking impulsivity was linked to upregulated INS to postcentral gyrus (PCG) and PCG to INS feedback. These preliminary findings suggest that glutamatergic-mediated sensory and emotion-regulation processes may function as potential suicide risk markers.

Impulsivity in fatal suicide behaviour: A systematic review and meta-analysis of psychological autopsy studies

Our aim is to review and perform a meta-analysis on the role of impulsivity in fatal suicide behaviour. We included papers who used psychological autopsy methodology, assessed adult death by suicide, and included assessment of impulsivity. We excluded papers about assisted suicide, terrorist suicide, or other cause of death other than suicide or postmortem diagnosis made only from medical records or database. 97 articles were identified. 33 were included in the systematic review and nine in the meta-analysis. We found that people who die by suicide with high impulsivity are associated with younger age, substance abuse, and low intention to die, whereas those with low impulsivity were associated with older age, depression, schizophrenia, high intention to die and low social support. In the meta-analysis, suicide cases had higher impulsivity scores than living controls (Hedges' g = 0.59, 95 % CI [0.28, 0.89], p=.002). However, studies showed heterogeneity (Q = 90.86, p<.001, I2=89.0 %). Impulsivity-aggressiveness interaction was assessed through meta-regression (β=0.447, p=.045). Individuals with high impulsivity would be exposed to a higher risk of fatal suicide behaviour, aggressiveness would play a mediating role. People who die by suicide with high and low impulsivity display distinct characteristics, which may reflect different endophenotypes leading to suicide by different pathways.

Decoding Suicide Decedent Profiles and Signs of Suicidal Intent Using Latent Class Analysis

Importance

Suicide rates in the US increased by 35.6% from 2001 to 2021. Given that most individuals die on their first attempt, earlier detection and intervention are crucial. Understanding modifiable risk factors is key to effective prevention strategies.

Objective

To identify distinct suicide profiles or classes, associated signs of suicidal intent, and patterns of modifiable risks for targeted prevention efforts.

Design, Setting, and Participants

This cross-sectional study used data from the 2003-2020 National Violent Death Reporting System Restricted Access Database for 306 800 suicide decedents. Statistical analysis was performed from July 2022 to June 2023.

Exposures

Suicide decedent profiles were determined using latent class analyses of available data on suicide circumstances, toxicology, and methods.

Main Outcomes and Measures

Disclosure of recent intent, suicide note presence, and known psychotropic usage.

Results

Among 306 800 suicide decedents (mean [SD] age, 46.3 [18.4] years; 239 627 males [78.1%] and 67 108 females [21.9%]), 5 profiles or classes were identified. The largest class, class 4 (97 175 [31.7%]), predominantly faced physical health challenges, followed by polysubstance problems in class 5 (58 803 [19.2%]), and crisis, alcohol-related, and intimate partner problems in class 3 (55 367 [18.0%]), mental health problems (class 2, 53 928 [17.6%]), and comorbid mental health and substance use disorders (class 1, 41 527 [13.5%]). Class 4 had the lowest rates of disclosing suicidal intent (13 952 [14.4%]) and leaving a suicide note (24 351 [25.1%]). Adjusting for covariates, compared with class 1, class 4 had the highest odds of not disclosing suicide intent (odds ratio [OR], 2.58; 95% CI, 2.51-2.66) and not leaving a suicide note (OR, 1.45; 95% CI, 1.41-1.49). Class 4 also had the lowest rates of all known psychiatric illnesses and psychotropic medications among all suicide profiles. Class 4 had more older adults (23 794 were aged 55-70 years [24.5%]; 20 100 aged ≥71 years [20.7%]), veterans (22 220 [22.9%]), widows (8633 [8.9%]), individuals with less than high school education (15 690 [16.1%]), and rural residents (23 966 [24.7%]).

Conclusions and Relevance

This study identified 5 distinct suicide profiles, highlighting a need for tailored prevention strategies. Improving the detection and treatment of coexisting mental health conditions, substance and alcohol use disorders, and physical illnesses is paramount. The implementation of means restriction strategies plays a vital role in reducing suicide risks across most of the profiles, reinforcing the need for a multifaceted approach to suicide prevention.

Potential Association Between Latent Toxoplasma gondii Infection and Suicide Attempts: A Case-Control Registry-Based Study

Toxoplasma gondii is a ubiquitous parasitic protozoan that may be an important cause of neurological and psychiatric diseases. The purpose of this case-control registry-based study was to evaluate the prevalence of T. gondii infection and related risk factors among subjects who attempted suicide by drug use and a control group at the Iranian National Registry Center for Toxoplasmosis in Mazandaran Province, northern Iran. Baseline data were collected from participants using a questionnaire, and a blood sample was taken from each individual. The plasma was prepared for serological analysis, whereas the buffy coat was used for molecular analysis. Out of 282 individuals (147 cases with suicide attempters [SA] and 135 controls), 42.9% of patients and 16.3% of control subjects were positive for anti-Toxoplasma immunoglobin G (IgG), but all participants were negative for T. gondii DNA and anti-Toxoplasma immunoglobin M. Based on multiple logistic regressions, IgG seropositivity in SA in the age group of 20-30 years was 3.22 times higher than that in the control group (p < 0.001). These findings suggest that latent T. gondii infection among SA is significantly higher than that in healthy individuals, indicating a potential association between latent toxoplasmosis and SA at least in the studied area. Further research is needed to shed light on the potential association between T. gondii and suicide among different populations and areas of the world.

Risk factors and their association network for young adults' suicidality: a cross-sectional study

BACKGROUND

Understanding the intricate influences of risk factors contributing to suicide among young individuals remains a challenge. The current study employed interpretable machine learning and network analysis to unravel critical suicide-associated factors in Chinese university students.

METHODS

A total of 68,071 students were recruited between Sep 2016 and Sep 2020 in China. Students reported their lifetime experiences with suicidal thoughts and behaviors, categorized as suicide ideation (SI), suicide plan (SP), and suicide attempt (SA). We assessed 36 suicide-associated factors including psychopathology, family environment, life events, and stigma. Local interpretations were provided using Shapley additive explanation (SHAP) interaction values, while a mixed graphical model facilitated a global understanding of their interplay.

RESULTS

Local explanations based on SHAP interaction values suggested that psychoticism and depression severity emerged as pivotal factors for SI, while paranoid ideation strongly correlated with SP and SA. In addition, childhood neglect significantly predicted SA. Regarding the mixed graphical model, a hierarchical structure emerged, suggesting that family factors preceded proximal psychopathological factors, with abuse and neglect retaining unique effects. Centrality indices derived from the network highlighted the importance of subjective socioeconomic status and education in connecting various risk factors.

CONCLUSIONS

The proximity of psychopathological factors to suicidality underscores their significance. The global structures of the network suggested that co-occurring factors influence suicidal behavior in a hierarchical manner. Therefore, prospective prevention strategies should take into account the hierarchical structure and unique trajectories of factors.

Ventromedial prefrontal cortex activation and neurofeedback modulation during episodic future thinking for individuals with suicidal thoughts and behaviors

Individuals experiencing suicidal thoughts and behaviors (STBs) show less specificity and positivity during episodic future thinking (EFT). Here, we present findings from two studies aiming to (1) further our understanding of how STBs may relate to neural responsivity during EFT and (2) examine the feasibility of modulating EFT-related activation using real-time fMRI neurofeedback (rtfMRI-nf). Study 1 involved 30 individuals with major depressive disorder (MDD; half with STBs) who performed an EFT task during fMRI, for which they imagined personally-relevant future positive, negative, or neutral events. Positive EFT elicited greater ventromedial prefrontal cortex (vmPFC) activation compared to negative EFT. Importantly, the MDD + STB group exhibited reduced vmPFC activation across all EFT conditions compared to MDD-STB; although EFT fluency and subjective experience remained consistent across groups. Study 2 included rtfMRI-nf focused on vmPFC modulation during positive EFT for six participants with MDD + STBs. Results support the feasibility and acceptability of the rtfMRI-nf protocol and quantitative and qualitative observations are provided to help inform future, larger studies aiming to examine similar neurofeedback protocols. Results implicate vmPFC blunting as a promising treatment target for MDD + STBs and suggest rtfMRI-nf as one potential technique to explore for enhancing vmPFC engagement.

The rs7208505 Polymorphism and Differential Expression of the SKA2 Gene in the Prefrontal Cortex of Suicide Victims from the Mexican Population

OBJECTIVE

The main aim of the current study was to investigate whether SKA2 gene expression in the postmortem brain of rs7208505 genotype are altered in suicide victims from a Mexican population.

METHODS

In this study, we report a genetic analysis of expression levels of the SKA2 gene in the prefrontal cortex of the postmortem brain of suicidal subjects (n = 22) compared to subjects who died of causes other than suicide (n = 22) in a Mexican population using RT-qPCR assays. Additionally, we genotyped the rs7208505 polymorphism in suicide victims (n = 98) and controls (n = 88) and we evaluate the association of genotypes for the SNP rs7208505 with expression level of SKA2.

RESULTS

The results showed that the expression of the SKA2 gene was significantly higher in suicide victims compared to control subjects (p = 0.044). Interestingly, we observed a greater proportion of allele A of the rs7208505 in suicide victims than controls. Even though there was no association between the SNP with suicide in the study population we found a significative association of the expression level from SKA2 with the allele A of the rs7208505 and suicide.

CONCLUSION

The evidence suggests that the expression of SKA2 in the prefrontal cortex may be a critical factor in the etiology of suicidal behavior.

Sex difference in association between suicide attempts and lipid profile in first-episode and drug naive patients with major depressive disorder

BACKGROUND

The relationship between suicide attempts and lipid profiles in patients with major depressive disorder (MDD) remains uncertain. The purpose of this study was to investigate sex differences in the relationship between suicide attempts and plasma lipid profiles in a large sample of first-episode and drug naive (FEDN) MDD patients.

METHODS

We recruited 1718 FEDN MDD patients and gathered demographic, clinical, and blood lipid data. The Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale and the Positive and Negative Syndrome Scale were used to assess the symptoms of patients.

RESULTS

There was no significant difference in the prevalence of suicide attempts between male and female MDD patients. The suicide attempt group had higher levels of depression, anxiety, psychotic symptoms, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C), but lower levels of high-density lipoprotein cholesterol (HDL-C) levels than the non-suicide attempt group. Binary logistic regression showed that TC levels were significantly correlated with suicidal attempts in both male and female patients. Correlation analysis revealed that the levels of TC, HDL-C and LDL-C were significantly associated with the number of suicide attempts in both male and female patients. Further multiple linear regression revealed that TC levels were significantly associated with the number of suicide attempts in male patients only.

CONCLUSIONS

Lipid biomarkers, particularly high TC levels, are associated with suicide attempts in both male and female MDD patients. However, there is gender difference in association between lipid biomarkers, especially TC levels, and the number of suicide attempts in MDD patients.

Genetic factors associated with suicidal behaviors and alcohol use disorders in an American Indian population

American Indians (AI) demonstrate the highest rates of both suicidal behaviors (SB) and alcohol use disorders (AUD) among all ethnic groups in the US. Rates of suicide and AUD vary substantially between tribal groups and across different geographical regions, underscoring a need to delineate more specific risk and resilience factors. Using data from over 740 AI living within eight contiguous reservations, we assessed genetic risk factors for SB by investigating: (1) possible genetic overlap with AUD, and (2) impacts of rare and low-frequency genomic variants. Suicidal behaviors included lifetime history of suicidal thoughts and acts, including verified suicide deaths, scored using a ranking variable for the SB phenotype (range 0-4). We identified five loci significantly associated with SB and AUD, two of which are intergenic and three intronic on genes AACSP1, ANK1, and FBXO11. Nonsynonymous rare and low-frequency mutations in four genes including SERPINF1 (PEDF), ZNF30, CD34, and SLC5A9, and non-intronic rare and low-frequency mutations in genes OPRD1, HSD17B3 and one lincRNA were significantly associated with SB. One identified pathway related to hypoxia-inducible factor (HIF) regulation, whose 83 nonsynonymous rare and low-frequency variants on 10 genes were significantly linked to SB as well. Four additional genes, and two pathways related to vasopressin-regulated water metabolism and cellular hexose transport, also were strongly associated with SB. This study represents the first investigation of genetic factors for SB in an American Indian population that has high risk for suicide. Our study suggests that bivariate association analysis between comorbid disorders can increase statistical power; and rare and low-frequency variant analysis in a high-risk population enabled by whole-genome sequencing has the potential to identify novel genetic factors. Although such findings may be population specific, rare functional mutations relating to PEDF and HIF regulation align with past reports and suggest a biological mechanism for suicide risk and a potential therapeutic target for intervention.

Depicting the molecular features of suicidal behavior: a review from an "omics" perspective

Background Suicide is one of the leading global causes of death. Behavior patterns from suicide ideation to completion are complex, involving multiple risk factors. Advances in technologies and large-scale bioinformatic tools are changing how we approach biomedical problems. The "omics" field may provide new knowledge about suicidal behavior to improve identification of relevant biological pathways associated with suicidal behavior. Methods We reviewed transcriptomic, proteomic, and metabolomic studies conducted in blood and post-mortem brains from individuals who experienced suicide or suicidal behavior. Omics data were combined using systems biology in silico, aiming at identifying major biological mechanisms and key molecules associated with suicide. Results Post-mortem samples of suicide completers indicate major dysregulations in pathways associated with glial cells (astrocytes and microglia), neurotransmission (GABAergic and glutamatergic systems), neuroplasticity and cell survivor, immune responses and energy homeostasis. In the periphery, studies found alterations in molecules involved in immune responses, polyamines, lipid transport, energy homeostasis, and amino and nucleic acid metabolism. Limitations We included only exploratory, non-hypothesis-driven studies; most studies only included one brain region and whole tissue analysis, and focused on suicide completers who were white males with almost none confounding factors. Conclusions We can highlight the importance of synaptic function, especially the balance between the inhibitory and excitatory synapses, and mechanisms associated with neuroplasticity, common pathways associated with psychiatric disorders. However, some of the pathways highlighted in this review, such as transcriptional factors associated with RNA splicing, formation of cortical connections, and gliogenesis, point to mechanisms that still need to be explored.

The association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) and suicidal ideation in adults: a population-based study in the United States

BACKGROUND

The ratio of non-high-density lipoprotein cholesterol (non-HDL-C) to high-density lipoprotein cholesterol (HDL-C) (NHHR) serves as a reliable lipid indicator associated with atherogenic characteristics. Studies have indicated a potential connection between suicidality and lipid metabolism. This research aims to investigate any possible association between the NHHR and the emergence of suicidal ideation within the confines of the study.

METHODS

This study examined the association between NHHR levels and suicidal ideation using data from the National Health and Nutrition Examination Survey (NHANES), conducted in the United States spanning 2005 and 2016. Calculation of the NHHR corresponds to the proportion of HDL-C to Non-HDL-C. The Patient Health Questionnaire-9's ninth question was implemented for assessing suicidal ideation. Using subgroup analysis, smooth curve fitting, and multivariate logistic regression analysis, the research was conducted.

RESULTS

Encompassing a cohort of 29,288 participants, the analysis identified that 3.82% of individuals reported suicidal ideation. After using multivariable logistic regression and thorough adjustments, elevated NHHR levels were significantly and positively associated with a heightened likelihood of suicidal ideation, according to the findings (odds ratio [OR] = 1.06; 95% confidence interval [CI]: 1.02-1.11; P = 0.0048). Despite extensive adjustment for various confounding factors, this relationship remained consistent. An inverted U-shaped curve was utilized to illustrate the link between NHHR and suicidal ideation among nonsmokers; the curve's inflection point was situated at 7.80. Subgroup analysis and interaction tests (all P for interaction > 0.05) demonstrated that there was no significant influence of the following variables on this positive relationship: age, sex, race, body mass index, education level, married status, hypertension, diabetes, and smoking status.

CONCLUSION

Significantly higher NHHR levels were associated with an elevated likelihood of suicidal ideation. Based on these results, it is probable that NHHR may serve as a predictive indicator of suicidal ideation, emphasizing its potential utility in risk assessment and preventive strategies.

EEG wakefulness regulation in transdiagnostic patients after a recent suicide attempt

OBJECTIVE

Decades of research have not yet produced statistically reliable predictors of preparatory behavior eventually leading to suicide attempts or deaths by suicide. As the nature of suicidal behavior is complex, it is best investigated in a transdiagnostic approach, while assessing objective markers, as proposed by the Research Domain Criteria (Cuthbert, 2013).

METHODS

A 15-min resting-state EEG was recorded in 45 healthy controls, and 49 transdiagnostic in-patients with a recent (<6 months) suicide attempt. Brain arousal regulation in eyes-closed condition was assessed with the Vigilance Algorithm Leipzig (VIGALL) (Sander et al., 2015).

RESULTS

A significant incline of median vigilance and vigilance slope was observed in patients within the first 3-min of the EEG recording. Additionally, a significant positive correlation of self-reported suicidal ideation with the vigilance slope over 15-min recording time, as well as a significant negative correlation with EEG vigilance stage A1 during the first 3-min was found.

CONCLUSIONS

Transdiagnostic patients with a recent suicide attempt show a distinct vigilance regulation pattern. Further studies including a control group consisting of patients without life-time suicide attempts are needed to increase the clinical utility of the findings.

SIGNIFICANCE

These findings might serve as potential objective markers of suicidal behavior.

Molecular Changes Associated with Suicide

Suicide is a serious global public health problem, with a worrying recent increase in suicide rates in both adolescent and adult populations. However, it is essential to recognize that suicide is preventable. A myriad of factors contributes to an individual's vulnerability to suicide. These factors include various potential causes, from psychiatric disorders to genetic and epigenetic alterations. These changes can induce dysfunctions in crucial systems such as the serotonergic, cannabinoid, and hypothalamic-pituitary-adrenal axes. In addition, early life experiences of abuse can profoundly impact an individual's ability to cope with stress, ultimately leading to changes in the inflammatory system, which is a significant risk factor for suicidal behavior. Thus, it is clear that suicidal behavior may result from a confluence of multiple factors. This review examines the primary risk factors associated with suicidal behavior, including psychiatric disorders, early life adversities, and epigenetic modifications. Our goal is to elucidate the molecular changes at the genetic, epigenetic, and molecular levels in the brains of individuals who have taken their own lives and in the plasma and peripheral mononuclear cells of suicide attempters and how these changes may serve as predisposing factors for suicidal tendencies.

Comorbidity of anxiety/affective, conduct/antisocial, attention deficit, and alcohol use disorders with suicidal behaviors in an American Indian community sample of adults and adolescents

AIMS

To study the associations of anxiety/affective disorders, conduct/antisocial disorders (ASPD/CD), attention deficit disorders (ADHD), and alcohol use disorders (AUD) with suicidal behaviors in an American Indian (AI) community sample of adolescents and adults.

METHODS

Participants were AI (360 adolescents, 925 adults) recruited from reservations who were assessed with the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA).

RESULTS

Among AI adults (mean age = 33 years), 17% percent reported lifetime experiences of suicidal thoughts (ideation and/or plans) and 14% reported suicidal acts (including either a suicide attempt history or verified death by suicide; n = 19 deaths). Among AI adolescents (mean age = 15 years), 20% experienced suicidal thoughts and 9% experienced suicidal acts (including 3 deaths). In logistic regression analyses, suicidal thoughts were significantly associated with lifetime diagnoses of affective disorder, CD and ADHD in adolescents, and with anxiety disorder, affective disorder, and ASPD/CD in adults. Suicidal acts were associated with affective disorder, ADHD, and alcohol drinking in adolescents and with anxiety disorder, ASPD/CD and AUD in adults. The number of comorbid disorders greatly increased the risk of both suicidal thoughts and acts among both adolescents and adults.

CONCLUSIONS

In addition to affective disorders, both ADHD and CD in adolescents, and ASPD in adults, demonstrated an association with suicidal thoughts. Alcohol use by adolescents and AUD among adults also were associated with suicidal attempts in this AI sample. These findings suggest need for additional research and potential integration of alcohol in screening and intervention programs focused on the prevention of suicide among AI.

"I Can't See an End in Sight." How the COVID-19 Pandemic May Influence Suicide Risk

Background: The COVID-19 pandemic and its consequences may affect population mental health and suicide risk. Aims: To explore the experiences among suicidal individuals who made calls to a suicide prevention hotline and to identify factors and psychological responses that may influence suicide risk. Method: We identified 60 eligible recorded calls to Taiwan's suicide prevention hotline (January 23, 2020-May 31, 2020) and analyzed the transcripts using a framework analysis. Results: We identified three themes: (a) effects of the COVID-19 pandemic on society (impacts on local economies, the fear of contagion, and disruptions caused by outbreak control measures); (b) stress experienced by callers, including increased challenges (financial burden, restricted freedom of movement, interpersonal conflicts, feelings of uncertainty, and education/career interruption) and reduced support (reduced access to health services and social support); and (c) the callers' psychological responses to stress, including anxiety, sleep disturbance, depression, loneliness, hopelessness, and entrapment, which may increase suicide risk. Limitations: Only the experiences among those who sought help by calling the hotline during the early months of the pandemic in 2020 were explored. Conclusion: Our findings revealed the potential process underlying the impact of the COVID-19 pandemic on suicide risk and have implications for prevention and intervention strategies.

Cognitive inflexibility and suicidal ideation among adolescents following hospitalization: The moderating role of life stress

BACKGROUND

Cognitive inflexibility has recently been investigated as potential vulnerability factor for suicidal ideation (SI), but the context in which it may convey risk is unclear. Life stress has also been reliably associated with SI among adolescents, and following a stress-diathesis model, may be a factor that moderates the relationship between cognitive inflexibility and SI.

METHODS

Psychiatrically hospitalized adolescents (N = 259) at high risk for future SI were followed for 18 months after discharge. Interviews assessing life stress and SI and a neurocognitive task assessing cognitive inflexibility were conducted at six- and 12-months. SI was also assessed at 18-month post-discharge. Linear mixed models were used to determine the moderating effect of stress on the relationship between cognitive inflexibility and SI, accounting for relevant clinical and demographic covariates.

RESULTS

Chronic stress moderated the association between cognitive inflexibility and SI, with a stronger association found among youth with greater levels compared to lower levels of chronic stress. This finding was maintained after statistically adjusting for depressive symptoms and relevant demographic covariates. No prospective associations between cognitive inflexibility, life stress, and SI were found.

LIMITATIONS

SI was measured at 6-month intervals, precluding evaluation of the relationship on a more proximal timescale.

CONCLUSIONS

Cognitively inflexible adolescents under conditions of high chronic stress are more likely to experience increased SI severity, supporting a cognitive inflexibility stress-diathesis model of SI in adolescents. The findings highlight the importance of assessing these modifiable factors among adolescents at a high risk for SI.

Suicide risk in male incarcerated individuals in Spain: clinical, criminological and prison-related correlates

BACKGROUND

Prison suicide is a complex phenomenon that may be influenced by individual, clinical, social and environmental factors. In Spain, few studies have explored the relationship with institutional, prison-related variables. The aim of this study is to examine correlates of suicide in a sample of male incarcerated individuals from 5 Spanish penitentiary centers.

METHODS

This present study entails a secondary data analysis, using data from the Prevalence of mental disorders in prisons study. This is a cross-sectional multicenter study conducted in 2007-2008 across 5 penitentiary centers in Spain. The Spanish version of the Plutchik suicide risk scale was used to assess the risk of suicide (those scoring ≥ 6 were considered to be at risk of suicide). Sociodemographic, clinical, criminological and prison-related data were collected via face-to face interviews and criminological data were confirmed using penitentiary records.

RESULTS

The final sample included 707 male incarcerated individuals (mean age 36.79 years ± 9.90 years). Several significant correlates associated with higher risk of suicide were identified including criminological factors (having committed a violent offense, being a recidivist), clinical factors (family history of mental disorders, the presence of mental disorders, having physical conditions, contact with a mental health specialist, medication treatment in the last 12 months), and prison-related determinants (workshop/training course participation) was significantly associated with lower suicide risk.

CONCLUSIONS

Several correlates within a comprehensive range of sociodemographic, criminological, clinical and prison-related variables were identified. This information is primordial for preventing suicide and reducing the existing risk. The findings may contribute to developing effective suicide prevention programs within Spanish prison services. Importantly, future research must continue to investigate the nature of suicidal outcomes among incarcerated individuals.

Relationship of stress-reactive cortisol to suicidal intent of prior attempts in major depression

Higher intent suicide attempts carry elevated risk of future suicidal behavior. Abnormal functioning of the hypothalamic-pituitary-adrenal (HPA) axis is both linked to nonfatal suicidal behavior and suicide deaths in major depressive disorder. Few studies, however, have identified biological markers of a high-intent suicidal subgroup. We examined HPA axis output and reactivity to the Trier Social Stress Test (TSST) via salivary cortisol in depressed individuals (N=68) with a suicide attempt (SA) history. A median split of higher and lower suicidal intent scores was used to define groups. Individuals with high intent SA had attenuated total cortisol output (AUCg), F(1,60)=10.04, SE=5.095, p=.003, and lower HPA-axis stress responsivity to the TSST (AUCi), F(1,60)=4.50, SE=4.604, p=.039, compared with the low intent SA group. The high intent group also reported more pronounced negative affect than the low intent group (F[1,61]=6.413, SE=10.55, p=.014) both at baseline (meandiff=22.32, p=.038) and in response to the stressor task (meandiff=37.62, p=.003). Vulnerability to suicidal behavior in high-intent individuals may be related to the combined profile of impaired physiological responses to stress and greater negative affectivity. This clinical and biologic subgroup may benefit from targeted suicide prevention interventions.

Differences of chronological seasonality in drug overdose

OBJECTIVE

To investigate the association between seasonality and intentional drug overdose (IDO), a commonly seen method of self-harm in daily emergency medicine practice.

METHODS

Cases of IDO were retrospectively selected using the International Classification of Diseases (ICD)-10 coding system (codes T36-T50), in patients who attended the Emergency Department of MacKay Memorial Hospital between January 2018 and August 2019. Data regarding age, sex, arrival time, marital status, vital signs, comorbidities, psychiatric history, social conflicts, substance of overdose, and length of hospital stay by season, were analysed using Student's t-test and χ2-test.

RESULTS

Of all included cases (n = 196), IDO occurred most frequently in spring (32.1%), particularly in male patients (28/49 male cases). First-time IDO occurred most frequently in spring (51/133 first-time cases) and most spring cases were first-time IDO (51/63 spring cases). Repeat IDO occurred most frequently in autumn (20/63 repeat cases). Female conflict with father and/or boyfriend, and personality disorder in patients who overdosed, showed seasonality with a spring peak. Hospital admission rate was highest in winter (10/45 winter cases [22.2%]).

CONCLUSION

Episodes of IDO exhibited seasonality, with a spring peak, particularly for male patients, female patients in conflict with father and/or boyfriend, and those with personality disorder. Clinicians should pay close attention to the abovementioned patient groups.

Prevalence and clinical correlates of psychotic symptoms in first-episode untreated female chinese patients with major depressive disorder

BACKGROUND

Recent studies have reported that psychotic symptoms are common in patients with major depressive disorder (MDD). However, few studies have reported the relationship between thyroid function, lipid metabolism and clinical profiles in female MDD patients. Thus, this study aimed to investigate the prevalence of psychotic depression (PD) and its risk factors in first-episode and drug naive (FEDN) depression among the female population in China.

METHODS

This was a cross-sectional study involving a representative probability sample of 1,130 FEDN female outpatients with MDD (aged 18 years or older) in China. We collected information relating to socio-demographic characteristics, clinical data and blood samples. The Hamilton Depression Rating Scale 17-item version (HAMD-17), Hamilton Anxiety Rating Scale 14-item version (HAMA-14), and Positive and Negative Syndrome Scale (PANSS) were used to evaluate depressive, anxiety, and psychotic symptoms.

RESULTS

The prevalence of psychotic symptoms in female MDD patients was 10.97%. The findings revealed significant differences between MDD female patients with psychotic symptoms and non-PD female patients in the following areas: higher HAMD scores, higher HAMA scores, more severe anxiety and an increased risk of suicide attempts. Further logistic regression analysis showed that psychotic symptoms were associated with higher thyroid-stimulating hormone (TSH) levels and an odds ratio of 1.168.

CONCLUSIONS

Our findings supported the hypothesis that higher TSH levels were correlated with psychotic symptoms in female MDD patients. Therefore, serum TSH levels may be a potential biomarker of PD in female MDD patients. In addition, we found that PD was closely associated with suicide attempts and lipid levels, but did not reach statistical significance.

Multiple serum biomarkers for predicting suicidal behaviours in depressive patients receiving pharmacotherapy

BACKGROUND

Predictive values of multiple serum biomarkers for suicidal behaviours (SBs) have rarely been tested. This study sought to evaluate and develop a panel of multiple serum biomarkers for predicting SBs in outpatients receiving a 12-month pharmacotherapy programme for depressive disorders.

METHODS

At baseline, 14 serum biomarkers and socio-demographic/clinical characteristics including previous suicidal attempt and present suicidal severity were evaluated in 1094 patients with depressive disorders without a bipolar diagnosis. Of these, 884 were followed for increased suicidal severity and fatal/non-fatal suicide attempt outcomes over a 12-month treatment period. Individual and combined effects of serum biomarkers on these two prospective SBs were estimated using logistic regression analysis after adjustment for relevant covariates.

RESULTS

Increased suicidal severity and fatal/non-fatal suicide attempt during the 12-month pharmacotherapy were present in 155 (17.5%) and 38 (4.3%) participants, respectively. Combined cortisol, total cholesterol, and folate serum biomarkers predicted fatal/non-fatal suicide attempt, and these with interleukin-1 beta and homocysteine additionally predicted increased suicidal severity, with clear gradients robust to adjustment (p values < 0.001).

CONCLUSIONS

Application of multiple serum biomarkers could considerably improve the predictability of SBs during the outpatient treatment of depressive disorders, potentially highlighting the need for more frequent monitoring and risk appraisal.

Suicide prevention and ketamine: insights from computational modeling

Suicide is a pressing public health issue, with over 700,000 individuals dying each year. Ketamine has emerged as a promising treatment for suicidal thoughts and behaviors (STBs), yet the complex mechanisms underlying ketamine's anti-suicidal effect are not fully understood. Computational psychiatry provides a promising framework for exploring the dynamic interactions underlying suicidality and ketamine's therapeutic action, offering insight into potential biomarkers, treatment targets, and the underlying mechanisms of both. This paper provides an overview of current computational theories of suicidality and ketamine's mechanism of action, and discusses various computational modeling approaches that attempt to explain ketamine's anti-suicidal effect. More specifically, the therapeutic potential of ketamine is explored in the context of the mismatch negativity and the predictive coding framework, by considering neurocircuits involved in learning and decision-making, and investigating altered connectivity strengths and receptor densities targeted by ketamine. Theory-driven computational models offer a promising approach to integrate existing knowledge of suicidality and ketamine, and for the extraction of model-derived mechanistic parameters that can be used to identify patient subgroups and personalized treatment approaches. Future computational studies on ketamine's mechanism of action should optimize task design and modeling approaches to ensure parameter reliability, and external factors such as set and setting, as well as psychedelic-assisted therapy should be evaluated for their additional therapeutic value.

Unlocking the Secrets: Exploring the Biochemical Correlates of Suicidal Thoughts and Behaviors in Adults with Autism Spectrum Conditions

Involving 1 million people a year, suicide represents one of the major topics of psychiatric research. Despite the focus in recent years on neurobiological underpinnings, understanding and predicting suicide remains a challenge. Many sociodemographical risk factors and prognostic markers have been proposed but they have poor predictive accuracy. Biomarkers can provide essential information acting as predictive indicators, providing proof of treatment response and proposing potential targets while offering more assurance than psychological measures. In this framework, the aim of this study is to open the way in this field and evaluate the correlation between blood levels of serotonin, brain derived neurotrophic factor, tryptophan and its metabolites, IL-6 and homocysteine levels and suicidality. Blood samples were taken from 24 adults with autism, their first-degree relatives, and 24 controls. Biochemical parameters were measured with enzyme-linked immunosorbent assays. Suicidality was measured through selected items of the MOODS-SR. Here we confirm the link between suicidality and autism and provide more evidence regarding the association of suicidality with increased homocysteine (0.278) and IL-6 (0.487) levels and decreased tryptophan (-0.132) and kynurenic acid (-0.253) ones. Our results suggest a possible transnosographic association between these biochemical parameters and increased suicide risk.

Genetic Factors Associated with Suicidal Behaviors and Alcohol Use Disorders in an American Indian Population

American Indians (AI) demonstrate the highest rates of both suicidal behaviors (SB) and alcohol use disorders (AUD) among all ethnic groups in the US. Rates of suicide and AUD vary substantially between tribal groups and across different geographical regions, underscoring a need to delineate more specific risk and resilience factors. Using data from over 740 AI living within eight contiguous reservations, we assessed genetic risk factors for SB by investigating: (1) possible genetic overlap with AUD, and (2) impacts of rare and low frequency genomic variants. Suicidal behaviors included lifetime history of suicidal thoughts and acts, including verified suicide deaths, scored using a ranking variable for the SB phenotype (range 0-4). We identified five loci significantly associated with SB and AUD, two of which are intergenic and three intronic on genes AACSP1, ANK1, and FBXO11. Nonsynonymous rare mutations in four genes including SERPINF1 (PEDF), ZNF30, CD34, and SLC5A9, and non-intronic rare mutations in genes OPRD1, HSD17B3 and one lincRNA were significantly associated with SB. One identified pathway related to hypoxia-inducible factor (HIF) regulation, whose 83 nonsynonymous rare variants on 10 genes were significantly linked to SB as well. Four additional genes, and two pathways related to vasopressin-regulated water metabolism and cellular hexose transport, also were strongly associated with SB. This study represents the first investigation of genetic factors for SB in an American Indian population that has high risk for suicide. Our study suggests that bivariate association analysis between comorbid disorders can increase statistical power; and rare variant analysis in a high-risk population enabled by whole-genome sequencing has the potential to identify novel genetic factors. Although such findings may be population specific, rare functional mutations relating to PEDF and HIF regulation align with past reports and suggest a biological mechanism for suicide risk and a potential therapeutic target for intervention.

Neurocognitive Suicide and Homicide Markers in Patients with Schizophrenia Spectrum Disorders: A Systematic Review

Suicide and homicide are considered important problems in public health. This study aims to identify the cognitive performance of suicidal and homicidal behaviors in people with schizophrenia spectrum disorders, as well as examining whether there are shared neuropsychological mechanisms. A systematic review of the recent literature was carried out from September 2012 to June 2022 using the Medline (via PubMed), Scopus, Embase, and Cochrane databases. Among the 870 studies initially identified, 23 were finally selected (15 related to suicidal behaviors and 8 to homicidal behaviors). The results evidenced a relationship between impairment of cognitive performance and homicidal behavior; meanwhile, for suicidal behaviors, no consistent results were found. High neuropsychological performance seems to act as a protective factor against violent behavior in people with schizophrenia spectrum disorders, but not against suicidal behavior; indeed, it can even act as a risk factor for suicidal behavior. To date, there is insufficient evidence that shared neurocognitive mechanisms exist. However, processing speed and visual memory seem to be affected in the presence of both behaviors.

Brain structural abnormalities and trait impulsivity in suicidal and non-suicidal patients with bipolar disorder

BACKGROUND

Impulsivity is a characteristic of patients with bipolar disorder (BD) and may result in a higher risk of suicide attempt (SA). Although brain structural abnormalities have been suggested in the pathophysiology of BD, the relationship to impulsivity and suicide in BD is still not clear.

METHODS

52 euthymic patients with BD (26 of them had a history of SA) and 56 age- and sex-matched healthy controls were recruited. All participants received clinical assessment, including Barratt impulsiveness scale (BIS), and underwent structural magnetic resonance imaging examination. An automated surface-based method (FreeSurfer) was used to measure brain volume and cortical surface area. A general linear model was applied to analyze the association between brain-wise greater gray matter volume (GMV), surface area and BIS scores separately for BD patients with and without SA history.

RESULTS

BD patients with SA history scored higher in BIS total score and subscores in attention, motor, cognitive complexity and cognitive instability than those without SA history and controls (all p < 0.01). In patients with SA history, higher BIS scores were associated with greater GMV in the left pars triangularis and greater surface area in left pars opercularis (all p < 0.01). BD patients with SA history showed a greater GMV in inferior frontal gyrus than patients without SA history (p < 0.05).

LIMITATION

The cross-sectional design precluded examination of chronological relationships of SA, brain structural abnormalities, and trait impulsivity among BD.

CONCLUSIONS

The findings indicate that the prefrontal cortex, especially the left inferior frontal gyrus, plays a vital role in trait impulsivity and suicidal behavior among patients with BD.

Increased Risk of Suicide Attempt in Patients with Alopecia Areata: A Nationwide Population-Based Cohort Study

BACKGROUND

There is growing evidence that patients with alopecia areata (AA) have an increased risk of developing psychiatric comorbidities. However, the relationship between AA and suicidal behaviors remains unclear.

OBJECTIVE

The objective of this study was to investigate the association between AA and suicidal behaviors.

METHODS

Participants were recruited from the National Health Insurance Research Database in Taiwan, including 10,515 patients with AA and 10,5150 matched controls, to assess the risk of suicide attempts. A Cox regression model was used for all analyses.

RESULTS

Compared with the controls, an increased risk of suicide attempts was observed in patients with AA, with an adjusted hazard ratio of 6.28 (95% confidence interval, 4.47-8.81). Suicide risk remained significantly elevated in AA patients when stratified by underlying psychiatric disorders. The mean age of initial suicidal behaviors was also lower in patients with AA.

CONCLUSIONS

Patients with AA had a significantly higher incidence of suicidal attempts than controls, regardless of concurrent psychiatric illness. Further studies are needed to elucidate the pathophysiology of the association between AA and suicidality. In addition, dermatologists should be aware of the increased suicidality of patients with AA.

Association between childhood cognitive skills & adult suicidal behavior: A systematic review and meta-analysis

BACKGROUND

It is unclear whether cognitive skill deficits during childhood carry risk for suicide attempt or mortality later in adulthood at the population level. We conducted a systematic review and meta-analysis of population-based studies examining the association between childhood cognitive skills and adult suicidal behavior, namely attempt and mortality.

METHOD

We systematically searched databases for articles then extracted study characteristics and estimates on the association between childhood cognitive skills (i.e., IQ or school performance at age ≤ 18 years) and later suicide attempt and mortality. Random-effect meta-analysis was used to quantify this association across all studies with available data.

RESULTS

Twenty-three studies met the inclusion criteria and suggest an association between lower childhood cognitive skills and increased risk of suicidal behavior. Meta-analysis of the adjusted estimates from 11 studies (N = 2,830,191) found the association to be small but statistically significant. Heterogeneity was significant but moderate, and results were unlikely to be influenced by publication bias. In subgroup analyses, associations were significant only for males. No difference in effect size was found between suicide attempt and suicide mortality.

LIMITATIONS

Cognitive skills were measured with different cognitive subtests. Heterogeneity in the age of cognitive skills assessment. Meta-regression and subgroup analyses were based on a relatively low number of studies.

CONCLUSIONS

Individuals with lower cognitive skills in childhood have a greater risk of suicidal behavior in adulthood, especially males. Although the association was small, interventions improving cognitive skills may yield large effects on suicide prevention at the population level if the association is causal.

Smaller rostral cingulate volume and psychosocial correlates in veterans at risk for suicide

Suicide research/clinical work remain in dire need of effective tools that can better predict suicidal behavior. A growing body of literature has started to focus on the role that neuroimaging may play in helping explain the path towards suicide. Specifically, structural alterations of rostral anterior cingulate cortex (rost-ACC) may represent a biological marker and/or indicator of suicide risk in Major Depressive Disorder (MDD). Furthermore, the construct of "grit," defined as perseverance for goal-attainment and shown to be associated with suicidality, is modulated by rost-ACC. The aim was to examine relationships among rost-ACC gray matter volume, grit, and suicidality in U.S. Military Veterans. Participants were age-and-sex-matched Veterans with MDD: with suicide attempt (MDD+SA:n = 23) and without (MDD-SA:n = 37). Groups did not differ in depression symptomatology. Participants underwent diagnostic interview, clinical symptom assessment, and 3T-MRI-scan. A Group (SA-vs.-No-SA) x Cingulate-region (rostral-caudal-posterior) x Hemisphere (left-right) mixed-model-multivariate-ANOVA was conducted. Left-rost-ACC was significantly smaller in MDD+SA, Group x Cingulate-region x Hemisphere-interaction. Lower grit and less left-rost-ACC gray matter each predicted suicide attempt history, but grit level was a more robust predictor of SA. Both structural alterations of rost-ACC and grit level represent potentially valuable tools for suicide risk assessment.

Understanding for Prevention: Qualitative and Quantitative Analyses of Suicide Notes and Forensic Reports

Suicide risk is associated with vulnerabilities and specific life events. The study's objective was to explore the relevance of data from forensic documentation on suicide deaths to the design of person-centered preventive strategies. Descriptive and thematic analyses were conducted of forensic observations of 286 deaths by suicide, including some with suicide notes. Key findings included the influence of health-and family-related adverse events, emotional states of loss and sadness, and failures of the health system to detect and act on signs of vulnerability, as confirmed by the suicide notes. Forensic documentation provides useful information to improve the targeting of preventive campaigns.

Moving suicide prevention upstream by understanding the effect of flourishing on suicidal ideation in midlife: an instrumental variable approach

Prior research has examined the association between flourishing and suicidal ideation, but it is unknown whether this association is causal. Understanding the causality between flourishing and suicidal ideation is important for clinicians and policymakers to determine the value of innovative suicide prevention programs by improving flourishing in at-risk groups. Using a linked nationwide longitudinal sample of 1619 middle-aged adults (mean age 53, 53% female, 88% White) from the National Survey of Midlife Development in the United States (MIDUS), this retrospective cohort study aims to assess the causal relationship between flourishing and suicidal ideation among middle-aged adults in the US. Flourishing is a theory-informed 13-scale index covering three domains: emotional, psychological, and social well-being. Suicidal ideation was self-reported in a follow-up interview conducted after measuring flourishing. We estimated instrumental variable models to examine the potential causal relationship between flourishing and suicidal ideation. High-level flourishing (binary) was reported by 486 (30.0%) individuals, and was associated with an 18.6% reduction in any suicidal ideation (binary) (95% CI, - 29.3- - 8.0). Using alternative measures, a one standard deviation increase in flourishing (z-score) was associated with a 0.518 (95% CI, 0.069, 0.968) standard deviation decrease in suicidal ideation (z-score). Our results suggest that prevention programs that increase flourishing in midlife should result in meaningful reductions in suicide risk. Strengthening population-level collaboration between policymakers, clinical practitioners, and non-medical partners to promote flourishing can support our collective ability to reduce suicide risks across social, economic, and other structural circumstances.

PsychArray-Based Genome Wide Association Study of Suicidal Deaths in India

Background: Suicide is a preventable but escalating global health crisis. Genome-wide association studies (GWAS) studies to date have been limited, and some are underpowered. In this study, we aimed to perform the PsychArray-based GWAS study to identify single nucleotide variations associated with suicide in the Indian population. Methods: We recruited unrelated subjects who died by suicide as cases (N = 313) and the non-suicidal deaths as controls (N = 294). The 607 samples were genotyped, including cases and controls using the Illumina Infinium PsychArray-24 BeadChip v1.3 Results: In our study, four single nucleotide polymorphisms (SNPs) crossed the threshold of significance level <1 × 10−5. One of them is intronic at Chromosome2:rs1901851 and three are intergenic at Chromosome12:rs3847911, Chromosome8:rs2941489, Chromosome8:rs1464092. At a significance level of 5 × 10−5, we found a few more SNPs, with the majority of them being intergenic variants. The associated genes were associated with various important functions ranging from cell signaling, GTP binding, GPCR binding, and transcription factor binding. Conclusions: The SNPs identified in our study were not reported earlier. To our best knowledge, this study is one of the first GWAS for suicide in the Indian population. The results indicate few novel SNPs that may be associated with suicide and require further investigation. Their clinical significance is to be studied in the future.

Suicide: An Overview for Clinicians

Most suicides have a diagnosable psychiatric disorder, most frequently, a mood disorder. Psychosocial issues and neurobiological abnormalities such as dysregulation in stress response systems contribute to suicidal behavior. All psychiatric patients need to be screened for the presence of suicidal ideation. Clinicians are expected to gather information about patient's clinical features and to formulate decisions about patient's dangerousness to self and the treatment plan. As psychiatric disorders are a major risk factor for suicide their pharmacologic and psychological treatment is of utmost importance to prevent suicide. Restriction of access to lethal means is important for suicide prevention.

Using type-2 fuzzy ontology to improve semantic interoperability for healthcare and diagnosis of depression

Ontology enhances semantic interoperability through integrating health data from heterogeneous sources and sharing information in a meaningful way. In the field of smart health services, semantic interoperability means the exchange and interpretation of data without ambiguity and uncertainty. However, existing classical ontologies are not able to represent vague and uncertain knowledge, especially in contexts of mental health disorders which are associated with varying degrees of uncertainty and inaccuracy of diagnosis, and in this case, the treatment is a complex and common mental process necessitating to share information accurately and unambiguously. Type-2 fuzzy set theory can offer a fruitful solution in order to control uncertainty or express ambiguous concepts in a dynamic and complex environment such as healthcare systems. Herein, a semantic framework for healthcare, and also monitoring mental health disorders using type-2 fuzzy set theory based on the Internet of Thing (IoT) is suggested, in which all depression-related concepts are semantically annotated to share detailed information with the treatment staff. This framework not only paved the way to increasing the accuracy of medical diagnosis and decision-making but also provides the possibility of inference and semantic reasoning using the languages of SPARQL query and DL query.

A recent suicide attempt and the heartbeat: Electrophysiological findings from a trans-diagnostic cohort of patients and healthy controls

Suicidal behavior is influenced by a multitude of factors, making prediction and prevention of suicide attempts (SA) a challenge. A useful tool to uncover underlying pathophysiology or propose new therapy approaches are biomarkers, especially within the context of point-of-care tests. Heart rate variability (HRV) is a well-established biomarker of mental health, and measures the activity of the sympathetic and parasympathetic nervous system (PNS). Previous studies reported a correlation between lower PNS activity and suicidality. However, most studies involved participants from a healthy population, patients without history of suicide attempts, or patients with a single diagnosis. 52 in-patients with a recent suicide attempt (<6 months), and 43 controls without history of SA or psychiatric diagnoses confirmed study participation. The included patients age ranged between 18 and 65 years, 65% had psychiatric comorbidities. Patients with dementia, cognitive impairments, acute psychosis, chronic non suicidal self-harming behavior, or current electroconvulsive therapy were excluded. A 15-min resting state electrocardiography was recorded with two bipolar electrodes attached to the right and left insides of the wrists. The multiple regression analyses showed lower parasympathetic, and higher sympathetic activity in patients compared to controls. Partial correlation found a positive trend result between self-reported suicidality and the very low frequency band. ROC curve analysis revealed an acceptable to excellent clinical accuracy of HRV parameters. Therefore, HRV parameters could be reliable discriminative biomarkers between in-patients with a recent SA and healthy controls. One limitation is the lack of a control group consisting of in-patients without life-time suicidal ideation or attempts.