Blunted HPA Axis Activity in Suicide Attempters Compared to those at High Risk for Suicidal Behavior

Higher levels of plasma Adrenocorticotropic hormone (ACTH) are associated with lower suicidal ideation in depressed patients compared to controls and suicide attempters, independently from depression severity

Introduction

Suicidal ideation, an important risk factor for suicide attempts, has an unclear neurobiological basis and is potentially linked to the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and immune-inflammatory systems. While inflammatory markers have been associated with suicide attempts and, to a lower extent suicidal ideation, the data on the role of a stress-response system is less robust, with most studies carried out with cortisol showing inconsistent results. The present study extends on the previous studies implicating stress-response and immune-inflammatory systems in suicidal thoughts and behaviours, focusing on the associations of several stress-response (adrenocorticotropic hormone (ACTH), cortisol, and dehydroepiandrosterone (DHEA)) and immune-inflammatory (C-reactive protein (CRP),interle ukin-6 (IL-6), and tumour necrosis factor-alpha (TNF-alpha)) with suicidal ideation severity in recent suicide attempters, patients with major depressive disorder, and non-psychiatric controls.

Methods

This observational study included 156 adults from three Vilnius hospitals, recruited into one of the three groups in equal parts: recent suicide attempters, patients with major depressive disorder in current depressive episode, and non-psychiatric controls. Measures included the Hamilton Depression Rating Scale (HDRS-17) and the Beck Scale for Suicide Ideation/Suicide Severity Index (BSS/SSI), alongside sociodemographic data, alcohol, tobacco use, and morning blood samples, measuring plasma ACTH, cortisol, DHEA, CRP, and IL-6. Data were analysed with non-parametric tests, Kendall's tau correlation, and multivariate linear regression adjusted for confounders.

Results

We found a negative correlation between the plasma ACTH levels and suicidal ideation severity (tau = -0.130, p = 0.033), which was driven by the patients with major depressive disorder (tau = -0.237, p = 0.031). Suicidal ideation severity was also negatively correlated with TNF-alpha (tau = -0.231; p < 0.001), positively correlated with IL-6 (tau = 0.154, p = 0.015), and CRP levels (tau = 0.153, p = 0.015), but no differences were observed in group-stratified analyses. The association between plasma ACTH levels and suicidal ideation severity in patients with major depressive disorder remained robust to adjustment for major confounders (adjusted for age, sex, education years, body mass index, smoking status, plasma CRP and PEth concentration (measuring chronic alcohol exposure), and antidepressant use) in the linear regression model (t = -2.71, p = 0.011), as well as additionally adjusting for depression severity (t = -2.99, p = 0.006).

Discussion

The present study shows an association between plasma ACTH levels and suicidal ideation severity in patients with major depressive disorder, robust to adjustment for antidepressant use and depression severity. This finding highlights the potential role of ACTH, in elucidating the effects of stress and mental health disorders. Our findings underscore the importance of the HPA axis in the diagnosis and treatment of suicidal ideation in major depressive disorder and invite further research on interventions targeting this pathway.

Associations between multiple sleep dimensions and suicide and non-suicidal self-injury: a cross-sectional study of 3828 Chinese young people

PURPOSE

Suicide and non-suicidal self-injury (NSSI) are preventable concerns in young people. Suicidal ideation (SI), suicidal plans (SP) and suicidal attempt (SA) are closely related to death. Sleep problems are known risk factors for suicide and NSSI. This study aimed to explore the relationship between sleep, suicidality and NSSI.

METHODS

Participants were 3,828 middle school and college students aged 11-23 years from urban and rural areas of Henan Province. Sleep, suicidal phenomena and NSSI were assessed by applying self-reported questionnaires. Chi-squared tests were utilized to demonstrate the demographic data and sleep variables. The correlation between sleep, suicidality and NSSI were explored by using binary logistic regression, while adjusting socio-demographic characteristics with multivariate models.

RESULTS

Sleep variables except mid-sleep time were related to suicidal phenomena (P < 0.05). Greater social jet lag (SJL) [≥ 2 h (h)] was associated with increased risk of SI [Odds ratios (OR) = 1.72, 95% confidence intervals (CI):1.40-2.11], SP (OR = 2.10, 95%CI:1.59-2.79) and SA (OR = 1.50, 95%CI:1.00-2.26). Non-only child participants with SJL (≥ 2 h) had significantly increased odds of SI (OR = 1.75, 95%CI: 1.41-2.18) and SP (OR = 2.25, 95%CI: 1.66-3.05). Eveningness chronotype had the strongest correlation with SI (OR = 3.87, 95%CI:2.78-5.38), SP (OR = 4.72, 95%CI:2.97-7.50), SA (OR = 6.69, 95%CI:3.08-14.52) and NSSI (OR = 1.39, 95%CI:1.02-1.90).

CONCLUSION

Overlong or short sleep duration, SJL, eveningness chronotype and other sleep abnormalities (e.g., daytime dysfunction, low sleep efficiency) were associated with a higher prevalence of SI, SP and SA. Additionally, eveningness was significantly correlated with NSSI among young people. These findings suggested the importance of assessing and intervening in sleep habits to prevent suicide and NSSI in young people.

Physiological stress reactivity and self-harm: A meta-analysis

OBJECTIVE

Self-harm is associated with alterations in the psychobiological stress response. Specifically, the reactivity of the autonomic nervous system (ANS) and the endocrine hypothalamic-pituitary-adrenal (HPA) axis may differ in individuals who engage in self-harm. However, evidence in this regard is inconsistent.

BACKGROUND

We conducted a preregistered random-effects meta-analysis of sympathetic ANS, parasympathetic ANS, sympathetic-parasympathetic, i.e., mixed-influence ANS, and HPA axis reactivity following laboratory stress exposure in individuals who engage in self-harm and controls. Stress exposure consisted of paradigms using either social-evaluative (e.g., TSST), emotional (e.g., negatively valenced visual stimuli), or physical (e.g., cold pressor test) challenges. A total of 29 studies (self-harm: n = 954, controls: n = 1122, 74% females) were included in the analysis.

RESULTS

Regarding ANS reactivity to stress, no differences emerged between the two groups. However, parasympathetic ANS activity was lower before stress (g = -0.30, CI -0.51 to -0.09) and after stressor cessation (g = 0.54, CI -1.07 to -0.01) in the self-harm group compared to controls. Regarding HPA axis reactivity, individuals who engage in self-harm showed significantly lower cortisol responses to stress than did controls (g = -0.26, CI -0.45 to -0.08). After stressor cessation (i.e., during stress recovery), cortisol was also lower in individuals who engage in self-harm compared to controls (g = -0.26, CI -0.43 to -0.08).

CONCLUSIONS

Lower basal parasympathetic ANS activity and flattened cortisol responses indicate dysregulation of psychobiological stress systems in individuals who engage in self-harm. A better understanding of the psychobiological underpinnings of self-harm may allow for the establishment of biomarkers of risk stratification and treatment monitoring in affected individuals.

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.

Youth Suicide in India: A Critical Review and Implication for the National Suicide Prevention Policy

Youth suicide is a significant public health problem in Low-and middle-income countries (LMIC), including India. It is a distinct phenomenon with various bio-psycho-social determinants. Despite this, comprehensive literature on this topic is lacking from India. Thus, the current paper aimed to review the available literature on youth-suicide from India and other LMIC, discusses the contentious issues, including potential solutions for the possible roadblocks, and provides recommendations for the national suicide-prevention policy and strategy (NSPPS) in the Indian context. We found that the magnitude of youth suicide in India is substantial with the distinct bio-psycho-social determinants. Although, youth-specific suicide prevention and therapeutic intervention do exist; its feasibility and effectivity in the Indian context are yet to be established. The is an urgent need for the NSPPS; experiences from other LMIC should be incorporated while framing such policies. More research is required from India in this area.

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.

Biobehavioral mechanisms underlying testosterone and mood relationships in peripubertal female adolescents

The pubertal transition is characterized by pronounced sex hormone fluctuation, refinement of affective neural circuitry, and an increased risk of depression in female adolescents. Sex hormones, including testosterone, exert modulatory effects on frontal-limbic brain networks and are associated with emotion dysregulation and depressive symptoms. Weekly changes in hormones predict affective symptoms in peripubertal female adolescents, particularly in the context of stress; however, the biobehavioral mechanisms underlying hormone change and mood relationships during the pubertal transition have yet to be determined and was the objective of the present study. Forty-three peripubertal female adolescents (ages 11-14) collected 8-weekly salivary hormone (estrone, testosterone) samples and mood assessments to evaluate hormone-mood relationships, followed by a biobehavioral testing session with psychosocial stress and EEG. Within-person correlations between weekly hormone changes and corresponding mood were performed to determine individual differences in mood sensitivity to weekly hormone change. Increased frontal theta activity indexing emotion reactivity, reduced cortisol reactivity, and reduced vagal efficiency predicted the strength of the relationship between testosterone and mood. Further, testosterone-sensitivity strength was associated with the enhancement of negative affect following stress testing. Results identify divergent frontal theta and stress responses as potential biobehavioral mechanisms underlying mood sensitivity to peripubertal testosterone fluctuation.

Effect of chronic unpredictable stress in female Wistar-Kyoto rats subjected to progesterone withdrawal: Relevance for Premenstrual Dysphoric Disorder neurobiology

Premenstrual Dysphoric Disorder (PMDD) is related to an abrupt drop in progesterone and impairments in the HPA axis that cause anxiety. Suffering persons report higher daily-life stress and anxiety proneness that may contribute to developing PMDD, considered a chronic stress-related disorder. Here, we explored the effect of chronic unpredictable stress (CUS) in rats subjected to progesterone withdrawal (PW) and evaluated gene expression of HPA axis activation in the stress-vulnerable Wistar-Kyoto (WKY) rat strain that is prone to anxiety. Ovariectomized WKY rats were randomly assigned to CUS or Standard-housed conditions (SHC) for 30 days. To induce PW, animals received 2 mg/kg of progesterone on day 25th for 5 days; 24 h later, they were tested using the anxiety-like burying behavior test (BBT). After behavioral completion, rats were euthanized, and brains were extracted to measure Crh (PVN) and Nr3c1 (hippocampus) mRNA. Blood corticosterone and vasopressin levels were determined. Results showed that PW exacerbated anxiety-like behaviors through passive coping in CUS-WKY. PW decreased Crh-PVN mRNA and the Nr3c1-hippocampal mRNA expression in SHC. CUS decreased Crh-PVN mRNA compared to SHC, and no further changes were observed by PW or BBT exposure. CUS reduced Nr3c1-hippocampal gene expression compared to SHC animals, and lower Nr3c1 mRNA was detected due to BBT. The PW increased corticosterone in SHC and CUS rats; however, CUS blunted corticosterone when combined with PW+BBT and similarly occurred in vasopressin concentrations. Chronic stress blunts the response of components of the HPA axis regulation when PW and BBT (systemic and psychogenic stressors, respectively) are presented. This response may facilitate less adaptive behaviors through passive coping in stress-vulnerable subjects in a preclinical model of premenstrual anxiety.

Implementing Evidence-Based Suicide Prevention Strategies for Greatest Impact

Suicide remains a leading cause of death in the United States and globally. In this review, epidemiological trends in mortality and suicide risk are presented, with consideration given to the impact of the COVID-19 pandemic. A public health model of suicide prevention with a community and clinical framework, along with advances in scientific discovery, offer new solutions that await widespread implementation. Actionable interventions with evidence for reducing risk for suicidal behavior are presented, including universal and targeted strategies at community, public policy, and clinical levels. Clinical interventions include screening and risk assessment; brief interventions (e.g., safety planning, education, and lethal means counseling) that can be done in primary care, emergency, and behavioral health settings; psychotherapies (cognitive-behavioral, dialectical behavior, mentalization therapy); pharmacotherapy; and systemwide procedures for health care organizations (training, policies, workflow, surveillance of suicide indicators, use of health records for screening, care steps). Suicide prevention strategies must be prioritized and implemented at scale for greatest impact.

DNA Methylation of Genes Involved in the HPA Axis in Presence of Suicide Behavior: A Systematic Review

DNA methylation in genes of the hypothalamic–pituitary–adrenal (HPA) axis has been associated with suicide behavior. Through a systematic review, we aimed to evaluate DNA methylation levels of the genes involved in the HPA pathway and their association with suicide behavior. A search of articles was performed using PubMed and Science Direct, EBSCO. The terms included were “DNA methylation”, “suicide”, “epigenetics”, “HPA axis” and “suicide behavior”. This systematic review was performed by the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement. Six studies comprising 743 cases and 761 controls were included in this systematic review. The studies included individuals with suicide ideation, suicide attempts or completed suicide and childhood trauma, post-traumatic stress disorder (PTSD), or depression. One study reported hypermethylation in GR in childhood trauma, while two studies found hypermethylation of NR3C1 in childhood trauma and major depressive disorder (MDD). Only one study reported hypermethylation in BNDF in people with MDD. FKBP5 was found to be hypermethylated in people with MDD. Another study reported hypermethylation in CRHBP. SKA2 was reported to be hypermethylated in one study and another study found hypomethylated both in populations with PTSD. CRHR1 was found to be hypermethylated in people with MDD, and the last study found hypomethylation in CRH. Our result showed that patients with suicidal behavior showed a DNA methylation state of genes of the HPA axis in association with psychiatric comorbidity and with adverse events. Genes of the HPA axis could play a role in suicidal behavior associated with adverse events and pathologies. As a result, DNA methylation levels, proteins, and genes involved in the HPA axis could be considered for the search for biomarkers for the prevention of suicidal behavior in future studies.

Psychological Morbidity After COVID-19 Critical Illness

Survivors of ICU hospitalizations often experience severe and debilitating symptoms long after critical illness has resolved. Many patients experience notable psychiatric sequelae such as depression, anxiety, and posttraumatic stress disorder (PTSD) that may persist for months to years after discharge. The COVID-19 pandemic has produced large numbers of critical illness survivors, warranting deeper understanding of psychological morbidity after COVID-19 critical illness. Many patients with critical illness caused by COVID-19 experience substantial post-ICU psychological sequelae mediated by specific pathophysiologic, iatrogenic, and situational risk factors. Existing and novel interventions focused on minimizing psychiatric morbidity need to be further investigated to improve critical care survivorship after COVID-19 illness. This review proposes a framework to conceptualize three domains of risk factors (pathophysiologic, iatrogenic, and situational) associated with psychological morbidity caused by COVID-19 critical illness: (1) direct and indirect effects of the COVID-19 virus in the brain; (2) iatrogenic complications of ICU care that may disproportionately affect patients with COVID-19; and (3) social isolation that may worsen psychological morbidity. In addition, we review current interventions to minimize psychological complications after critical illness.

The impulsiveness level influences the salivary cortisol response and social stress sensitivity in suicidal patients

INTRODUCTION

Suicide attempters (SA) are more vulnerable to social stress and show disturbed cortisol response in stressful conditions compared with psychiatric and healthy controls. Recent data suggest that this dysregulation might be related to impulsivity traits. However, little is known about the emotional consequences of social stress in SA exposed to stress.

OBJECTIVES

The aim of our study was to evaluate the cortisol and emotional responses to social stress in patients with depression with and without suicide attempt, by taking into account impulsivity traits and depression severity.

METHODS

67 adult women (41 SA and 26 affective controls (AC,i.e. without suicide attempt history)) with lifetime history of major depressive episode were included. Patients performed the Trier Social Stress Test (TSST), a well-validated social stress task. Patients provided seven saliva samples, to measure the cortisol response, and filled in questionnaires to assess psychological pain, positive and negative mood, and anxiety at different time points (from 10 min before to 120 min after the TSST). Moderated regression models were used including suicide attempt history, depression severity, and impulsivity as independent variables and their interactions.

RESULTS

In patients with low depression and high impulsivity, salivary cortisol response during the TSST was higher in SA than in AC (p < .001). Psychological pain, negative mood, and anxiety were increased in all patients just after the TSST, followed by a decrease at 120 min. Positive mood recovery was slower in SA, and in patients with high impulsivity and low depression level (p < .001).

CONCLUSIONS

Impulsivity traits have an important role in suicidal vulnerability in stress conditions. Impulsivity traits might help to differentiate patients at risk of suicide who are highly sensitive to stress when depression level is low. Higher impulsiveness may increase the sensitivity to emotional distress that translates into inadequate physiological responses.

Alcohol use history increases the likelihood of suicide behavior among male chronic patients with schizophrenia in a Chinese population

AIMS

This study was designed to detect the association between the history of alcohol drinking and suicidality in schizophrenia (SCZ) inpatients in a Chinese population.

METHODS

We recruited 616 male SCZ inpatients and collected demographic and clinical data. Five-factor model of the Positive and Negative Syndrome Scale (PANSS) was used to assess their psychopathological symptoms.

RESULTS

Our results showed that 31.33% of SCZ patients had a history of alcohol drinking. They had higher rates of lifetime suicide attempt and suicidal ideation than those without a history of alcohol drinking. Moreover, patients with a history of drinking were more likely to attempt suicide (14.51% vs. 7.09%; χ²  = 7.70, df = 1, p = 0.006), with an odds ratio (OR) of 2.22 and have suicidal ideation (29.02% vs. 17.49%; χ²  = 9.89, df = 1, p = 0.002), with an OR of 1.93. In addition, patients who used to drink alcohol were more likely to be smokers and had more severe positive and depressive symptoms (all p < 0.05).

CONCLUSIONS

Our study indicates that history of alcohol drinking may increase the prevalence of lifetime suicide attempt and suicidal ideation in male patients with chronic SCZ. Moreover, the history of alcohol drinking may be associated with some demographic data and clinical symptoms.

Increased burden of cardiovascular risk among youth suicide attempters

BACKGROUND

Suicide and cardiovascular disease rank among the leading causes of disability and premature mortality worldwide. Young adult suicide attempters are at increased risk of mortality from cardiovascular disease even compared to those with major depressive disorder suggesting an increased burden of cardiovascular risk factors. We compared the cardiovascular risk burden between youth attempters and other high-risk individuals.

METHODS

Participants were from the Collaborative Psychiatric Epidemiology Surveys (CPES), a U.S. population-based study, aged 18-30 years [suicide attempt (SA): n = 303; suicidal ideation (SI): n = 451; controls: n = 3671]; and psychiatric inpatients admitted for a SA (n = 38) or SI (n = 40) and healthy controls (n = 37) aged 15-30 years. We computed a cardiovascular risk score and high- and low-risk latent classes based on risk factors of high blood pressure, obesity, and smoking.

RESULTS

Suicide attempters showed an increased cardiovascular risk score (CPES: B = 0.43, 95% confidence interval (CI) 0.31-0.54, p < 0.001; inpatient sample: B = 1.61, 95% CI 0.53-2.68, p = 0.004) compared to controls. They were also more likely to be classified in the high cardiovascular risk group (CPES: odds ratio (OR) 3.36, 95% CI 1.67-6.78, p = 0.001; inpatient sample: OR 9.89, 95% CI 1.38-85.39, p = 0.03) compared to those with SI (CPES: OR 1.15, 95% CI 0.55-2.39, p = 0.71; inpatient sample: OR 1.91, 95% CI 0.25-15.00, p = 0.53).

CONCLUSIONS

Youth attempters show an increased burden for cardiovascular risk compared to other high-risk individuals in inpatient and population-based samples. Clinicians should pay particular attention to cardiovascular risk factors among suicide attempters in order to reduce their risk for cardiovascular events.

Blood hormones and suicidal behaviour: A systematic review and meta-analysis

This study was to evaluate the relationship between blood hormone levels and suicidal behaviour. We reviewed Web of Science, PubMed and Embase for literature published up to 10 April 2022. Studies were restricted to English-language articles. Studies measuring blood hormone levels in suicidal and non-suicidal subjects were eligible. Standardized mean differences (SMDs) were applied to evaluate group differences. Overall, 57 studies were eligible, of which 51 evaluated suicide attempts, and 9 assessed suicidal ideation. Random-effects meta-analysis indicated that levels of thyrotropin stimulating hormone (TSH) (SMD = 0.50; 95% CI, 0.27-0.72), leptin (SMD = -1.16; 95% CI, -1.94 to -0.38) and dehydroepiandrosterone sulfate (DHEAS) (SMD = -0.67; 95% CI, -1.13 to -0.21) were related to suicide attempts, whereas progesterone levels (SMD = 0.22; 95% CI, 0.03-0.41) were related to suicidal ideation. This analysis offers evidence linking abnormalities of blood hormones with suicidal behaviour, which may be essential for identifying individuals with suicide attempts and suicidal ideation. Large prospective studies are needed for further clarification of roles of hormones in suicidal behaviour.

Effects of stress on endophenotypes of suicide across species: A role for ketamine in risk mitigation

Suicide is a leading cause of death and morbidity worldwide, yet few interventions are available to mitigate its risk. Barriers to effective treatments involve a limited understanding of factors that predict the onset of suicidal thoughts and behaviors. In the context of suicide risk, stress is a precipitating factor that is largely overlooked in the literature. Indeed, the pathophysiology of stress and suicide are heavily interconnected, underscoring the need to target the stress system in suicide prevention. In this review, we integrate findings from the preclinical and clinical literature that links stress and suicide. We focus specifically on the effects of stress on underlying biological functions and processes associated with suicide, allowing for the review of research using animal models. Owing to the rapid anti-suicidal effects of (R,S)-ketamine, we discuss its ability to modulate various stress-related endophenotypes of suicide, as well as its potential role in preventing suicide in those with a history of chronic life stress (e.g., early life adversity). We highlight future research directions that could advance our understanding of stress-related effects on suicide risk, advocating a dimensional, endophenotype approach to suicide research.

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Suicide and chronic stress pathophysiology are interconnected.

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Chronic stress has profound impacts on several endophenotypes of suicide.

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Animal and human research points to stress as a precipitating factor in suicide.

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Ketamine modulates specific biological processes associated with stress and suicide.

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Suicide research into endophenotypes can help inform risk-mitigation strategies.

Associations of three major physiological stress systems with suicidal ideation and suicide attempts in patients with a depressive and/or anxiety disorder

BACKGROUND

People with depressive and/or anxiety disorders are at increased risk of suicidal ideation and suicide attempts, but biological correlates signaling such risk remain unclear. Independent and cumulative dysregulations in physiological stress systems, in particular the hypothalamic-pituitaryadrenal axis (HPA-axis), immune-inflammatory system, and autonomous nervous system (ANS), may contribute to this risk. However, findings have either been heterogeneous or absent thus far.

METHODS

Associations between individual markers and cumulative indices of the HPA-axis (cortisol awakening response and evening cortisol), immune-inflammatory system (C-reactive protein, interleukin-6 (IL-6), and tumor necrosis factor-α), and the ANS (heart rate, respiratory sinus arrhythmia, and pre-ejection period) and the outcomes no suicide ideation with suicide attempt (SI-SA+), suicide ideation without suicide attempt (SI+SA-) and suicide ideation with suicide attempt (SI+SA+) were investigated in 1749 persons with depressive and/or anxiety disorders from the Netherlands Study of Depression and Anxiety (NESDA).

RESULTS

High levels of CRP and IL-6 were associated with SI-SA+ and SI+SA+ respectively when compared to non-suicidal patients after adjusting for confounders and multiple testing. Also, cumulative immune-inflammatory dysregulations were positively associated with SI+SA+, suggesting a dose-response effect. No significant associations were found between HPA-axis or ANS indicators and suicide-outcomes and between immune-inflammatory system markers or cumulative stress system dysregulations and SI+SA-.

CONCLUSION

Although stress system markers could not differentiate between SI+SA- and non-suicidal patients, findings indicate that dysregulations of individual and cumulative immune-inflammatory markers are associated with suicide attempts in depressive and/or anxiety patients. Thus, immune-inflammatory system dysregulation may be involved in the pathophysiology of suicidal behavior, supporting further examination of the effects of anti-inflammatory interventions on suicidality.

Suicide: Allostatic regulation and resilience

Suicide is a complex public health problem that is the result of a number of intertwined biopsychosocial factors. The diathesis-stress model suggests that suicide is the result of an interaction between genetic vulnerability and environmental stressors. Chronic stress and trauma contribute to biologic adaptations, including hypothalamus-pituitary-adrenal axis dysregulation, that contribute to the degradation of regulatory mechanisms and promote wear and tear the body, represented by allostatic load (AL). AL has been associated with a number of negative outcomes, including mental health problems and suicide. Fortunately, there are pharmacological and non-pharmacological interventions that are effective at reducing AL and reversing its effects. Thus, AL may provide a construct for supporting early risk identification, prevention, and treatment of suicide. AL biomarkers that are amenable to measurable change, effective treatments to reduce AL and perhaps help prevent suicide, and how to best tailor them to the individual and societal levels are important avenues of therapeutic inquiry.

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.

Oral ketamine reduces the experience of stress in people with chronic suicidality

BACKGROUND

Stress is prevalent in people experiencing suicidality and is a major contributor to the development of mental disorders. Evidence suggests ketamine shows capacity to reverse stress-induced brain changes. Though stress and ketamine have been explored individually for suicidality, this study is the first to examine ketamine treatment for self-reported stress in adults with chronic suicidality, building on pre-clinical evidence of ketamine's capacity to normalize stress-induced responses and contributing to our understanding of oral ketamine in clinical populations.

METHODS

Thirty two adult participants (22-72 years; 17 female) with chronic suicidality completed 6 weeks of active treatment, receiving low (0.5 mg/kg - 3.0 mg/kg) doses of oral ketamine once per week, with a 4-week follow-up phase, to assess the effect of ketamine on their perceived stress. Stress was measured via self-report utilizing the Depression Anxiety Stress Scale-21(DASS-21), and analysed at pre-treatment (week 0), post-treatment (week 6) and at follow-up (week 10).

RESULTS

Repeated measures ANOVA showed a significant reduction in stress (p<.001) post-treatment and Reliable Change Index calculations confirmed this to be clinically significant. Furthermore, those classified as 'prolonged responders' demonstrated a sustained reduction in stress at follow-up (i.e. after 4 weeks of nil ketamine).

LIMITATIONS

Small sample size, open label design, expectancy, secondary analysis CONCLUSIONS: Ketamine showed the capacity to produce a robust and sustained improvement in stress symptoms, in people with chronic suicidality. Future larger, controlled studies examining treatment suitability in a range of stress related disorders are warranted.

Associations of serum cortisol levels, stress perception, and stressful events with suicidal behaviors in patients with depressive disorders

BACKGROUND

Stress is a well-known risk factor of suicide. However, there is a lack of research on the best psychobiological markers of stress for monitoring and predicting suicidal behaviors in depressed patients. We aimed to investigate the individual and interactive effects of serum cortisol levels and stress-related parameters, including perceived stress and life stressors, on suicidal behavior in depressed patients.

METHODS

At baseline, serum cortisol levels were measured and stress-related data, i.e., Perceived Stress Scale (PSS) scores and the number of stressful life events (SLEs), were collected from 1,094 patients with a depressive disorder, of whom 884 were followed up for 1 year. Suicidal behaviors evaluated at baseline included previous suicide attempts and baseline suicidal severity, while those at the 1-year follow-up were increased suicidal severity and fatal/non-fatal suicide attempts. Individual and interactive associations of exposure variables with suicidal outcomes were analyzed using logistic regression models after adjusting for relevant covariates.

RESULTS

Higher serum cortisol levels were significantly associated with suicidal outcomes at the 1-year follow-up. In addition, higher PSS scores were significantly associated with higher baseline severity, whereas the number of SLEs was not associated with any suicidal outcomes. A significant interactive effect of cortisol level and PSS score on suicidal outcomes at the 1-year follow-up was observed. Higher cortisol levels and PSS scores were associated with increased suicidal severity and more fatal/non-fatal suicide attempts.

CONCLUSIONS

The combination of serum cortisol levels and PSS scores may be useful for monitoring and predicting suicidal behaviors in depressed patients.

Basal and reactive cortisol: A systematic literature review of offspring of parents with depressive and bipolar disorders

One of the most consistent biological findings in the study of affective disorders is that those with depression commonly show abnormal cortisol response, which suggests dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. Children of parents with mood disorders offer the opportunity to explore the biological pathways that may confer risk for psychopathology. This review explores basal and reactive cortisol in the offspring of parents who are currently depressed or have had a history of a depressive or bipolar disorder. Using PRISMA guidelines, search terms yielded 2002 manuscripts. After screening, 87 of these manuscripts were included. Results from the literature suggest that while the degree and direction of dysregulation varies, offspring of a parent with depression tend to show elevations in both basal (particularly morning and evening) and reactive (tentatively for social stressors) cortisol levels. There were few studies focused on offspring of parents with bipolar disorder. This review also discusses implications and recommendations for future research regarding the HPA axis in the intergenerational transmission of depressive disorders.

Catalytic Reaction Model of Suicide

Suicide is a devastating outcome of unresolved issues that affect mental health, general wellbeing and socioeconomic stress. The biology of suicidal behavior is still poorly understood, although progress has been made. Suicidal behavior runs in families and genetic studies have provided initial glimpses into potential genes that contribute to suicide risk. Here, we attempt to unify the biology and behavioral dimensions into a model that can guide research in this area. The proposed model envisions suicidal behavior as a catalytic reaction that may result in suicide depending on the conditions, analogously to enzyme catalysis of chemical reactions. A wide array of substrates or reactants, such as hopelessness, depression, debilitating illnesses and diminished motivation can mobilize suicidal thoughts and behaviors (STBs), which can then catalyze the final step/act of suicide. Here, we focus on three biological substrates in particular: threat assessment, motivation to engage in life and impulsivity. Genetic risk factors can affect each of these processes and tilt the balance toward suicidal behavior when existential crises (real or perceived) emerge such as loss of a loved one, sudden changes in social status or serious health issues. Although suicide is a uniquely human behavior, many of the fundamental biological processes are evolutionarily conserved. Insights from animal models may help to shape our understanding of suicidal behavior in man. By examining counterparts of the major biological processes in other organisms, new ideas about the role of genetic risk factors may emerge along with possible therapeutic interventions or preventive measures.

Increased Levels of Cortisol in Individuals With Suicide Attempt and Its Relation With the Number of Suicide Attempts and Depression

BACKGROUND

Abnormalities in the hypothalamic-pituitary-adrenal axis (HPA) have been reported in individuals with suicide behavior. The aim of the study was to evaluate cortisol levels in peripheral plasma of individuals with more than one suicide attempt.

METHODS

Cortisol concentrations in peripheral plasma were measured using the ELISA technique. Suicide attempts were evaluated by the Columbia Suicide Severity Rating Scale, while depression was evaluated by the Hamilton Depression Rating Scale.

RESULTS

We found elevated cortisol levels in the suicide attempt group when compared with healthy controls (F = 7.26, p-value = 0.008), but no statistical differences with the psychiatric diseases group (F = 1.49, p-value = 0.22). Cortisol levels were higher in individuals with depression (F = 8.99, P = 0.004) and in individuals with two or more suicide attempts (F = 13.56, P < 0.001).

CONCLUSIONS

Cortisol levels are increased in individuals who attempt suicide and higher of cortisol concentrations in plasma regard to depression and more attempts of suicide.

Recurrent suicide attempts affect normalization of HPA axis dysregulation after recovery from major depression

More than 700,000 people worldwide die by suicide every year, and the number of suicide attempts is estimated as 20 times higher, most of them being associated with psychiatric disorders, especially major depression. Knowledge about effective methods for preventing suicide attempts in individuals at high risk for suicide is still scarce. Dysregulation of the neuroendocrine stress response system, i.e., the hypothalamic-pituitary-adrenocortical (HPA) axis, is one of the most consistent neurobiological findings in both major depression and suicidality. While the HPA axis is mostly overactive in depression, individuals with a history of suicide attempts exhibit an attenuated hormonal response to stress. It is unknown, however, whether the HPA axis is constantly attenuated in repeated suicide attempters or whether it regains normal responsivity after recovery from depression. Using the combined dexamethasone suppression/corticotropin-releasing hormone (dex/CRH) test, we assessed HPA axis regulation in acute depression (N = 237) and after recovery with respect to previous suicide attempts. Patients without previous suicide attempts show normalization of the stress hormone response to the second dex/CRH (basal ACTH response and cortisol response) after recovery from acute depression, while patients with multiple previous SA show an increased ACTH response. The change in HPA axis responsivity in patients with only one previous SA lies between the response patterns of the other groups with no change in HPA axis reactivity. Our findings suggest that patients with a history of suicide attempts belong to a subgroup of individuals that exhibit a distinct pattern of stress hormone response during acute depression and after recovery. Future studies may extend our approach by investigating additional psychological stress tasks to gain a broader understanding of the stress pathology of recurrent suicide attempters.

Advances in Research on Adolescent Suicide and a High Priority Agenda for Future Research

Suicide is the second leading cause of death for adolescents in the United States, yet remarkably little is known regarding risk factors for suicidal thoughts and behaviors (STBs), relatively few federal grants and scientific publications focus on STBs, and few evidence-based approaches to prevent or treat STBs are available. This "decade in review" article discusses five domains of recent empirical findings that span biological, environmental, and contextual systems and can guide future research in this high priority area: (1) the role of the central nervous system; (2) physiological risk factors, including the peripheral nervous system; (3) proximal acute stress responses; (4) novel behavioral and psychological risk factors; and (5) broader societal factors impacting diverse populations and several additional nascent areas worthy of further investigation.

Analysis of Suicidal Behavior and Chronicity of Depressive Symptoms in the Presence of Hypovitaminosis D

Background:

One of the risk factors for suicide includes the presence of depressive disorder and symptoms, which may be related to the reduction of 25-hydroxyvitamin D serum levels. In this scenario, evidence shows vitamin D deficiency as an important aspect, directly related to depressive disorder chronicity.

Objective:

To assess the association between Vitamin D serum levels and the intensity of depressive symptoms and suicidal behavior in a clinical sample of depressed patients.

Methods:

A cross-sectional study with 146 patients aged between 18 and 59, seen in two psychiatry ambulatories. Data collection involved measurement of serum 25-hydroxyvitamin D levels and assessment of the intensity of depressive symptoms and suicide risk.

Results:

In the sample, 35% presented low Vitamin D serum levels and, in these individuals, the incidence of family history of Depressive Disorder (95.2%) and chronicity of severe depressive symptoms (47.8%) was higher. As to suicidal behavior, both groups presented high active suicide risk, with higher rates in the group with hypovitaminosis D. Only suicidal ideation was linked to lower Vitamin D levels (67.4% p= 0,005).

Conclusion:

In this study, hypovitaminosis D was associated with negative mental health outcomes, such as more severe chronicity of depressive symptoms and suicidal behavior, characterized by active suicidal ideation.

A secondary analysis of a brief video intervention on suicidal ideation among recent rape victims

Although rape has been linked to risk for suicidal ideation and attempts, there are scant data on the efficacy of brief interventions to reduce suicidality among recent rape victims. This secondary analysis of a randomized controlled trial investigated whether a video intervention delivered in the emergency department (ED), cortisol measured at the ED, and prior rape history predicted postrape suicidal ideation independently or in combination with the other predictors. Participants were 235 women aged 15-71 years who presented to the ED for a sexual assault medical forensic examination and were randomly assigned to either receive a video intervention that addressed avoidance and promoted healthy coping strategies or standard care prior to the examination. Participants also provided a blood sample for cortisol and completed at least one of three follow-ups at 6 weeks, 3 months, or 6 months postrape. The intervention conferred protection against suicidal ideation among women with elevated cortisol and a prior rape; however, it did not reduce risk for women without a prior rape, particularly those with elevated cortisol. It may be important to consider the influence of prior rape and neuroendocrine reactivity in developing treatments to address suicidal ideation among rape victims. More specifically, there appears to be value in screening victims for prior rape and administering this brief intervention to reduce suicidal ideation; however, other avenues should be explored for victims without a prior rape history. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Resilience and vulnerability factors influence the cortisol awakening response in individuals vulnerable to suicide

Suicide is a global health issue. Dysregulated hypothalamic-pituitary-adrenal (HPA) axis activity, as measured by cortisol levels, has been identified as one potential risk factor. Evidence is emerging to suggest that different psychological factors may be associated with increased resilience and vulnerability in this context. The current study investigated whether trait resilience, social support, socially prescribed perfectionism, trait worry and trait impulsivity influenced the cortisol awakening response (CAR) over a 7-day study in individuals vulnerable to suicide. 142 participants with a history of suicidal attempt or ideation (suicide vulnerability group; n = 95) and with no suicide risk history (control group; n = 47) were recruited. Participants completed baseline questionnaires before commencing a 7-day study where they provided cortisol samples immediately upon waking, at 15 min, 30 min and 45 min on 7 consecutive days. Higher worry, socially prescribed perfectionism and impulsivity, lower resilience and social support were found in the suicide vulnerability group compared to the control group. Lower levels of resilience, higher levels of socially prescribed perfectionism, worry and impulsivity were associated with significantly lower total CAR. Suicide group membership was also found to have an indirect effect on total CAR via trait worry. The current findings show for the first time, that these well-known psychological risk factors for suicide are associated with smaller total cortisol awakening responses. Researchers ought to elucidate the precise causal mechanisms linking these traits, CAR and suicide risk in order to develop interventions to help build resilience in vulnerable populations.

Brain 5-HT1A Receptor PET Binding, Cortisol Responses to Stress, and the Familial Transmission of Suicidal Behavior

BACKGROUND

The serotonin 1A (5-HT1A) receptor has been implicated in depression and suicidal behavior. Lower resting cortisol levels are associated with higher 5-HT1A receptor binding, and both differentiate suicide attempters with depression. However, it is not clear whether 5-HT1A receptor binding and cortisol responses to stress are related to familial risk and resilience for suicidal behavior.

METHODS

[11C]CUMI-101 positron emission tomography imaging to quantify regional brain 5-HT1A receptor binding was conducted in individuals considered to be at high risk for mood disorder or suicidal behavior on the basis of having a first- or second-degree relative(s) with an early onset mood disorder and history of suicidal behavior. These high-risk individuals were subdivided into the following groups: high risk resilient having no mood disorder or suicidal behavior (n = 29); high risk with mood disorder and no suicidal behavior history (n = 31); and high risk with mood disorder and suicidal behavior (n = 25). Groups were compared with healthy volunteers without a family history of mood disorder or suicidal behavior (n = 34). Participants underwent the Trier Social Stress Task (TSST). All participants were free from psychotropic medications at the time of the TSST and PET scanning.

RESULTS

We observed no group differences in 5-HT1A receptor binding considering all regions simultaneously, nor did we observe heterogeneity of the effect of group across regions. These results were similar across outcome measures (BPND for all participants and BPp in a subset of the sample) and definitions of regions of interest (ROIs; standard or serotonin system-specific ROIs). We also found no group differences on TSST outcomes. Within the high risk with mood disorder and suicidal behavior group, lower BPp binding (β = -0.084, SE = 0.038, P = .048) and higher cortisol reactivity to stress (β = 9.25, 95% CI [3.27,15.23], P = .004) were associated with higher lethality attempts. There were no significant relationships between 5-HT1A binding and cortisol outcomes.

CONCLUSIONS

5-HT1A receptor binding in ROIs was not linked to familial risk or resilience protecting against suicidal behavior or mood disorder although it may be related to lethality of suicide attempt. Future studies are needed to better understand the biological mechanisms implicated in familial risk for suicidal behavior and how hypothalamic-pituitary-adrenal axis function influences such risk.

Effects of weariness of life, suicide ideations and suicide attempt on HPA axis regulation in depression

The neuropathological mechanisms leading to suicidality are still unknown, which, in view of an annual toll of around 1 million completed suicides constitutes an urgent clinical and societal problem. Alterations of stress hormone (ACTH and cortisol, representing the activity of the hypothalamic-pituitary-adrenocortical, HPA axis) regulation has been repeatedly studied in context of suicidality. Following a suicide attempt, stress hormone activity seems to be blunted, while depressed patients with suicidal ideation often present with elevated HPA axis activity.

METHODS

We investigated the effects of different forms of suicidality on HPA axis regulation in 568 hospitalized patients of the Munich Antidepressant Response Signature (MARS) project. All patients had a diagnosis of a depressive disorder; 62 patients reported a recent suicide attempt, 192 patients suicide ideation, and 171 patients expressed weariness of life as the weakest form of suicidality, the latter not being analyzed in studies so far. All patients participated in the combined dexamethasone/corticotropin releasing hormone (dex/CRH) test for assessing HPA axis regulation shortly after admission to the hospital.

RESULTS

We found an increased ACTH and cortisol response following the dex/CRH-test in patients that were weary of life. In contrast, stress hormone response in suicide attempters and suicide ideators did not differ from non-suicidal patients. Further, repeated suicide attempts in patients' history were associated with more pronounced stress hormone attenuation.

CONCLUSION

In this so far largest study analyzing the HPA axis with respect to suicidality, we could not confirm the assumption of a general attenuation of HPA axis response in depressed suicide ideators and attempters. Conversely, HPA axis appears to be influenced by divergent effects of a specific suicidal psychopathology as well as outlasting effects of previous suicide attempts. We discuss these findings in the light of recent concepts of suicidality, pointing to multifactorial effects of acute and predisposing conditions on HPA axis reactivity in depressed patients.

Prevalence, course, and determinants of suicide ideation and attempts in patients with a depressive and/or anxiety disorder: A review of NESDA findings

BACKGROUND

Depressive and anxiety disorders are often associated with suicide ideation (SI) and attempt (SA). However, analyses of prevalence, course, and more specific risk mechanisms are needed to improve knowledge and detection of high risk individuals with depressive and anxiety disorders. Previous studies often lacked statistical power, assessment of detailed determinants and follow-up measurements.

METHODS

The Netherlands Study of Depression and Anxiety (NESDA), a large cohort study, overcomes some earlier limitations. Scale for Suicide Ideation and Compositive Interview Diagnostic Instrument data were analyzed to report on prevalence of SI and SA. Additionally, important sociodemographic, clinical, psychological, environmental, and neurobiological determinants and course of SI and SA identified in depressive and/or anxiety disorder respondents in 16 NESDA articles were summarized.

RESULTS

Within respondents with 12-month diagnosis (n=1,783), SI and 12-month SA prevalence ranged from 17.1-20.1% and 0.8-3.0% respectively across 5 waves during 9-year follow-up and SI was highly recurrent. Both SI and SA were especially associated with comorbid depression and anxiety, higher clinical severity, sleep dysfunctions, higher aggression and hopelessness, and childhood trauma. In the (neuro)biological domain, SI was linked with immune dysregulation and SA with abnormal brain activity during emotion processing and genetic risk.

LIMITATIONS

Most articles were cross-sectional in nature, preventing causal inferences and no conclusions could be drawn about the overall magnitude of results.

CONCLUSION

SI and SA are multifactorial phenomena and especially prevalent amongst comorbid depressive and anxiety respondents. Considering many overlapping SI and SA determinants, more neurobiological determinants and use of innovative methodological techniques are desirable.

Modeling endophenotypes of suicidal behavior in animals

Suicide is a major public health concern. One of the common contributors to the increased risk for suicide is the genetic constitution of individuals, which determines certain endophenotypic traits used as quantifiable measure of neurobiological functions. Therefore, a logical deconstruction of the originating endophenotypes associated with suicidal risk could provide a better understanding of this complex disorder. In this regard, non-human animals can be a useful resource to test endophenotypes of suicidal behavior and the neurobiology underlying these endophenotypes. In this review, we have focused on the neurobiological abnormalities, primarily genetic and epigenetic abnormalities, associated with suicidal behavior and the scope of their modeling in animals. This can substantially advance the current understanding of suicidal behavior manifested with certain trait-based endophenotypes and may provide an opportunity to test novel hypotheses as well as aid in the development of treatment opportunities and risk assessment.

How Does COVID-19 Affect the Neurobiology of Suicide?

PURPOSE OF REVIEW

The aim of this review was to analyze COVID-19 effect on the biological features of suicidal vulnerability and its interaction with suicide-related biological pathways. We carried out a narrative review of international publications on the interactions of COVID-19 with the biological bases of suicide.

RECENT FINDINGS

We hypothesize that SARS-CoV-2 interacts with multiple biological processes that underlie suicidal behavior, such as the renin-angiotensin system, nicotinic receptors, and central and systemic inflammation. Social distancing measures may also worsen subjective or objective social disconnection, thus increasing the risk of suicide. Interestingly, the drugs used to prevent suicide could be promising options to counteract brain damage caused by this coronavirus. SARS-CoV-2 interacts with multiple biological pathways involved in suicide and opens a new window for understanding the suicidal process. The development of suicide prevention treatments in the context of a pandemic may benefit from knowledge on these interactions.

GABAA Receptor Subunit Transcriptional Regulation, Expression Organization, and Mediated Calmodulin Signaling in Prefrontal Cortex of Rats Showing Testosterone-Mediated Impulsive Behavior

Testosterone can induce impulsivity, a behavioral impairment associated with various psychiatric illnesses. The molecular mechanisms associated with testosterone-induced impulsivity are unclear. Our earlier studies showed that supraphysiological doses of testosterone to rats induced impulsive behavior, impacted hypothalamic-pituitary-adrenal axis (HPA) and hypothalamic-pituitary-gonadal axis interactions, and altered α_2A adrenergic receptors in prefrontal cortex (PFC). Owing to the importance of GABAergic system in impulsivity and memory, the present study examines whether testosterone-mediated impulsivity is associated with changes in the expression of Gamma-Aminobutyric Acid (GABA) A and B receptor subunit transcripts (Gabra1, Gabra2, Gabra2 transcript variant 2, Gabra3, Gabra4, Gabra5, Gabra6, Gabrb1, Gabrb2, Gabrb3, Gabrg1, Gabrg2, Gabrg3, Gabbr1, Gabbr2) in rat PFC, and whether testosterone influences GABA_A receptor subunit organization. We studied GABA receptor functions by examining GABA receptor-mediated calcium/calmodulin-dependent kinase signaling genes (Calm1, Calm2, Calm3, Camk2a, Camk2b, Camk2g, Camk2d, Camk4) in the testosterone-induced impulsivity model. Rats were left untreated as controls (C), gonadectomized (GDX), or GDX and injected with supraphysiological doses of testosterone (T). Impulsive behavior was examined using the go/no-go paradigm. Gene expression was studied using qRT-PCR and GABA_A subunit reorganization using cross correlation. Our findings show that expressions of select GABA_A receptor subunits (Gabra3, Gabra5, Gabra6) were significantly upregulated in PFC of T group compared to GDX or C groups. GABA_A receptor subunit organization was different in C, T, and GDX groups. Additionally, Camk4 expression was significantly downregulated in T compared to C group. Our findings suggest that specific GABA_A receptor subunit expression, their reorganization, and Camk4-mediated functions may be associated with testosterone-mediated impulsivity.

The Involvement of Hypothalamus-Pituitary-Adrenal (HPA) Axis in Suicide Risk

Stress and Hypothalamic–Pituitary–Adrenal (HPA) axis dysregulation play a major role in various pathophysiological processes associated with both mood disorders and suicidal behavior. We conducted a systematic review with the primary aim of clarifying the nature and extent of HPA axis activity and suicidal behavior. The second aim of this review was to investigate whether potential biomarkers related to HPA axis abnormalities act as individual susceptibility factors for suicide. The PRISMA statement for reporting systematic reviews was used. Only articles published in English peer-reviewed journals were considered for possible inclusion; we excluded case reports, meta-analyses, and systematic reviews, and studies that did not clearly report statistical analysis, diagnostic criteria, or the number of patients included. Overall, 36 articles on HPA axis and suicide risk met inclusion criteria and were reviewed. Studies that investigated tests detecting biomarkers and the role of early life stressors in suicide risk were also included. We found that HPA axis activity is involved in suicide risk, regardless of the presence or absence of psychiatric conditions. The HPA axis abnormalities, mainly characterized by hyperactivity of the HPA axis, may exert an important modulatory influence on suicide risk. Impaired stress response mechanisms contribute to suicide risk. Targeting HPA axis dysregulation might represent a fruitful strategy for identifying new treatment targets and improving suicide risk prediction.

Stress, cortisol and suicide risk

Suicide is a global health issue accounting for at least 800,000 deaths per annum. Numerous models have been proposed that differ in their emphasis on the role of psychological, social, psychiatric and neurobiological factors in explaining suicide risk. Central to many models is a stress-diathesis component which states that suicidal behavior is the result of an interaction between acutely stressful events and a susceptibility to suicidal behavior (a diathesis). This article presents an overview of studies that demonstrate that stress and dysregulated hypothalamic-pituitary-adrenal (HPA) axis activity, as measured by cortisol levels, are important additional risk factors for suicide. Evidence for other putative stress-related suicide risk factors including childhood trauma, impaired executive function, impulsivity and disrupted sleep are considered together with the impact of family history of suicide, perinatal and epigenetic influences on suicide risk.

Stress Response in Suicide Attempters with Borderline Personality Disorder: The Role of Behavioral Problems in Childhood

Objective: Suicidal individuals are a heterogeneous population and may differ in systematic ways in their responsiveness to stress. The primary aim of the present study was to identify whether a different pattern of physiological stress response exists among adult suicide attempters with a history of behavioral problems during childhood and adolescence, which earlier studies have related to both decreased activity of the HPA axis and to suicidal behaviors. Method: Seventy-eight participants with Borderline Personality Disorder were assessed using the SCID-II, and completed self-report measures assessing their history of suicide attempts, history of aggressive behaviors, depressive symptoms, history of lifetime abuse and demographics. Participants' cortisol reactivity was assessed using the Trier Social Stress Test. Results: Analyses indicated that suicide attempters with a history of behavioral problems in youth (n = 30) had a significantly lower response to stress than both suicide attempters without such a history (n = 26) and non-attempters (n = 22), when controlling for lifetime history of abuse. The groups did not differ in basal cortisol. Conclusions: These findings suggest a unique subtype of suicide attempter among those with Borderline Personality Disorder, characterized by a blunted physiological stress response.

Microglial Dysregulation and Suicidality: A Stress-Diathesis Perspective

According to the stress-diathesis model of suicidal behavior, completed suicide depends on the interaction between psychosocial stressors and a trait-like susceptibility. While there are likely multiple biological processes at play in suicidal behavior, recent findings point to over-activation of microglia, the resident macrophages of the central nervous system, as implicated in stress-induced suicidal behavior. However, it remains unclear how microglial dysregulation can be integrated into a clinical model of suicidal behavior. Therefore, this narrative review aims to (1) examine the findings from human post-mortem and neuroimaging studies that report a relationship between microglial activation and suicidal behavior, and (2) update the clinical model of suicidal behavior to integrate the role of microglia. A systematic search of SCOPUS, PubMed, PsycINFO, and Embase databases revealed evidence of morphological alterations in microglia and increased translocator protein density in the brains of individuals with suicidality, pointing to a positive relationship between microglial dysregulation and suicidal behavior. The studies also suggested several pathological mechanisms leading to suicidal behavior that may involve microglial dysregulation, namely (1) enhanced metabolism of tryptophan to quinolinic acid through the kynurenine pathway and associated serotonin depletion; (2) increased quinolinic acid leading to excessive N-methyl-D-aspartate-signaling, resulting in potential disruption of the blood brain barrier; (3) increased quinolinic acid resulting in higher neurotoxicity, and; (4) elevated interleukin 6 contributing to loss of inhibition of glutamatergic neurons, causing heightened glutamate release and excitotoxicity. Based on these pathways, we reconceptualized the stress-diathesis theory of suicidal behavior to incorporate the role of microglial activity.

Biological bases of suicidal behaviours: A narrative review

Suicidal behaviour is a multifaceted phenomenon that concerns all human populations. It has been suggested that a complex interaction between the individual genetic profile and environmental factors throughout life underlies the pathophysiology of suicidal behaviour. Although epidemiological and genetic studies suggest the existence of a genetic component, exposure to biological and psychosocial adversities, especially during critical developmental periods, also contributes to altering the biological responses to threat and pleasure. This results in amplified maladaptive cognitive and behavioural traits and states associated with suicidal behaviours. Alterations in the cognitive inhibition and decision-making capacity have been implicated in suicidal behaviours. Structural and functional changes in key brain regions and networks, such as prefrontal cortex, insula and default mode network, may underlie this relationship. Furthermore, the shift from health to suicidal behaviour incorporates complex and dynamic changes in the immune and stress responses, monoaminergic system, gonadal system and neuroplasticity. In this review, we describe the major findings of epidemiological, genetic, neuroanatomical, neuropsychological, immunological and neuroendocrinological studies on suicide behaviours to provide a solid background for future research in this field. This broad overview of the biological bases of suicide should promote neuroscience research on suicidal behaviours. This might lead to improved biological models and to the identification of evidence-based biomarkers, treatment options and preventive strategies.

Adolescent nonsuicidal self-injury and cortisol response to the retrieval of adversity: A sibling study

BACKGROUND

There is evidence for alterations in hypothalamus-pituitary-adrenal (HPA) axis response to the retrieval of traumatic events among individuals with Posttraumatic Stress Disorder. However, no study has so far investigated HPA response to trauma retrieval among individuals engaging in non-suicidal self-injury (NSSI). In the present study, we compared reports of childhood adversity (CA) between adolescents engaging in NSSI and their siblings and tested for differences in the cortisol response to the retrieval of CA.

METHODS

The sample consisted of 32 adolescents engaging in NSSI (M_age = 15.8 years) and their siblings (M_age = 15.6 years). Standardized interviews were used for the assessment of CA, NSSI, and axis I diagnoses. Salivary cortisol was measured before and after the trauma interview. Basal HPA axis activity was measured in hair.

RESULTS

Reports of CA were moderately interrelated between siblings. Adolescents engaging in NSSI reported more severe CA. A significant decrease of salivary cortisol during the trauma interview was found only in the NSSI group. The NSSI group had significantly higher hair cortisol levels.

CONCLUSIONS

Moderate relations in siblings' reports of CA point to non-shared experiences that may play a role in the development of NSSI. In the NSSI group, the decrease of salivary cortisol during the interview may be explained by a downregulation of the HPA axis subsequent to the retrieval of former experience of CA.

Suicide and suicide risk

Although recent years have seen large decreases in the overall global rate of suicide fatalities, this trend is not reflected everywhere. Suicide and suicidal behaviour continue to present key challenges for public policy and health services, with increasing suicide deaths in some countries such as the USA. The development of suicide risk is complex, involving contributions from biological (including genetics), psychological (such as certain personality traits), clinical (such as comorbid psychiatric illness), social and environmental factors. The involvement of multiple risk factors in conveying risk of suicide means that determining an individual's risk of suicide is challenging. Improving risk assessment, for example, by using computer testing and genetic screening, is an area of ongoing research. Prevention is key to reduce the number of suicide deaths and prevention efforts include universal, selective and indicated interventions, although these interventions are often delivered in combination. These interventions, combined with psychological (such as cognitive behavioural therapy, caring contacts and safety planning) and pharmacological treatments (for example, clozapine and ketamine) along with coordinated social and public health initiatives, should continue to improve the management of individuals who are suicidal and decrease suicide-associated morbidity.

Suicidal subtypes, stress responsivity and impulsive aggression

While prominent models of suicidal behavior emphasize the hypothalamic- pituitary-adrenal (HPA) axis dysregulation, studies examining its role have yielded contradictory results. One possible explanation is that suicide attempters are a heterogeneous group and HPA axis dysregulation plays a more important role only in a subset of suicidal individuals. HPA axis dysregulation also plays a role in impulsivity and aggression. We hypothesize subgroups of attempters, based on levels of impulsivity and aggression, will differ in HPA axis dysregulation. We examined baseline cortisol, total cortisol output, and cortisol reactivity in mood disordered suicide attempters (N = 35) and non-attempters (N = 37) during the Trier Social Stress Test. Suicide attempters were divided into four subgroups: low aggression/low impulsivity, high aggression/low impulsivity, low aggression/high impulsivity, and high aggression/high impulsivity. As hypothesized, attempters and non-attempters did not differ in any cortisol measures while stress response differed based on impulsivity/aggression levels in suicide attempters, and when compared to non-attempters. Specifically, attempters with high impulsive aggression had a more pronounced cortisol response compared with other groups. This is the first study to examine the relationship between cortisol response and suicidal behavior in impulsive aggressive subgroups of attempters. These findings may help to identify a stress responsive suicidal subtype of individuals.

Cortisol response to stress as a predictor for suicidal ideation in youth

OBJECTIVE

To examine the association between cortisol response to stress and suicidal ideation (SI) cross-sectionally and longitudinally in our sample of bereaved and non-bereaved youth.

METHODS

The sample included 114 youth bereaved by sudden parental death and 109 non-bereaved controls, mean age of 12.3 (SD = 3.6), evaluated at four time-points over an average follow-up period of 7 years. The Trier Social Stress Test (TSST) was conducted on average 6 years after bereavement. We used latent class analyses to examine the trajectories of SI over follow-up and up to the time of the TSST and compare them on cortisol measures. We examined whether cortisol measures predicted future SI at 18.5 months on average after the TSST.

RESULTS

Bereavement was associated with higher cortisol reactivity after controlling for covariates [β = 0.96, 95% CI (0.28, 1.65), p < 0.01, d = 0.41]. Cortisol reactivity to stress was higher in those belonging to the high SI trajectory [β = 1.23, 95% CI (0.41, 2.06), p = 0.004, d = 0.23] compared to the low SI trajectory. Higher baseline cortisol showed small to medium effect size in predicting future SI [β = 2.34, 95% CI (0.17, 4.51), p = 0.03, d = 0.38].

CONCLUSION

The persistence of SI is associated with higher cortisol reactivity to stress, and higher baseline cortisol may predict future SI. These results emphasize the importance of HPA-axis activity in youth exposed to major stressors, and those with SI. More research is needed to further clarify biological mechanisms linking SI and behavior, bereavement, and HPA axis response to stress, to better identify at-risk subjects for targeted prevention and intervention efforts.

Novel Treatment Targets Based on Insights in the Etiology of Depression: Role of IL-6 Trans-Signaling and Stress-Induced Elevation of Glutamate and ATP

Inflammation and psychological stress are risk factors for major depression and suicide. Both increase central glutamate levels and activate the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system. Both factors also affect the function of the chloride transporters, Na-K-Cl-cotransporter-1 (NKCC1) and K-Cl-cotransporter-2 (KCC2), and provoke interleukin-6 (IL-6) trans-signaling. This leads to measurable increases in circulating corticosteroids, catecholamines, anxiety, somatic and psychological symptoms, and a decline in cognitive functions. Recognition of the sequence of pathological events allows the prediction of novel targets for therapeutic intervention. Amongst others, these include blockade of the big-K potassium channel, blockade of the P2X4 channel, TYK2-kinase inhibition, noradrenaline α2B-receptor antagonism, nicotinic α7-receptor stimulation, and the Sgp130Fc antibody. A better understanding of downstream processes evoked by inflammation and stress also allows suggestions for tentatively better biomarkers (e.g., SERPINA3N, MARCKS, or ¹³C-tryptophan metabolism).

Extraversion modulates cortisol responses to acute social stress in chronic major depression

BACKGROUND

Chronic Major Depressive Disorder (CMDD) is a common, disabling illness that is often complicated by high reactivity to social stress. To further elucidate the nature of this reactivity, the current study evaluated whether the personality dimensions of neuroticism and extraversion influenced cortisol responses to a social challenge in CMDD patients vs. controls.

METHODS

Fifty participants with CMDD and 58 healthy controls completed the Trier Social Stress Test (TSST) using a standard protocol. Neuroticism and extraversion were measured using the Revised NEO Personality Inventory. Hierarchical linear regressions assessed associations between independent variables neuroticism and extraversion and dependent variable cortisol area-under-the-curve increase (AUCi) in response to the TSST in the two study groups.

RESULTS

The extraversion-by-group interaction was a significant predictor of cortisol AUCi, while no significant findings related to neuroticism were found. Simple slopes analysis revealed a significant negative association between extraversion and AUCi in the CMDD group, but not in healthy controls. Post-hoc analysis of the raw cortisol data over time found that CMDD participants with higher extraversion scores had significantly higher pre-challenge cortisol levels than did other study participants, however this did not explain or confound the AUCi results.

CONCLUSIONS

In participants with CMDD but not in controls, higher levels of extraversion were associated with higher pre-challenge cortisol levels and decreased cortisol reactivity during the TSST, however these two findings were statistically independent. These findings underline the importance of considering personality factors when studying stress biology in CMDD patients. Extraversion may prove to be an important intermediate target for both research and clinical work in this complex, heterogenous and often treatment-resistant population.