Abnormal stress responsiveness and suicidal behavior: A risk phenotype

Child maltreatment and youth suicide risk: A developmental conceptual model and implications for suicide prevention

Experiences of child abuse and neglect are risk factors for youth suicidal thoughts and behaviors. Accordingly, suicide risk may emerge as a developmental process that is heavily influenced by the rearing environment. We argue that a developmental, theoretical framework is needed to guide future research on child maltreatment and youth (i.e., adolescent and emerging adult) suicide, and to subsequently inform suicide prevention efforts. We propose a developmental model that integrates principles of developmental psychopathology and current theories of suicide to explain the association between child maltreatment and youth suicide risk. This model bears significant implications for future research on child maltreatment and youth suicide risk, and for suicide prevention efforts that target youth with child maltreatment experiences.

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.

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.

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.

Suicide and self-harm

Suicide and self-harm are major health and societal issues worldwide, but the greatest burden of both behaviours occurs in low-income and middle-income countries. Although rates of suicide are higher in male than in female individuals, self-harm is more common in female individuals. Rather than having a single cause, suicide and self-harm are the result of a complex interplay of several factors that occur throughout the life course, and vary by gender, age, ethnicity, and geography. Several clinical and public health interventions show promise, although our understanding of their effectiveness has largely originated from high-income countries. Attempting to predict suicide is unlikely to be helpful. Intervention and prevention must include both a clinical and community focus, and every health professional has a crucial part to play.

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.

Effects of a cognitive-behavioral skills building program on the mental health outcomes and healthy lifestyle behaviors of veterinary medicine students

OBJECTIVE

To evaluate the effects of a cognitive-behavioral skills building program (ie, MINDSTRONG; The Ohio State University) on the mental health outcomes and healthy lifestyle beliefs and behaviors of Doctor of Veterinary Medicine (DVM) students.

Sample

DVM students (n = 62) before beginning their program at a large public Midwest land-grant university.

Procedures

All 171 incoming DVM students (class of 2024) were required to take the cognitive-behavioral skills building program (7 weeks in length) before starting their 2020 school year. Students were given the option to consent to the study portion of the program. Consenting participants completed a pre- and postsurvey containing demographic questions and 5 valid and reliable scales, including the Patient Health Questionnaire-9 that assesses depressive symptoms, the Generalized Anxiety Disorder-7 that evaluates anxiety, the Brief Inventory of Perceived Stress that measures stress, and the Healthy Lifestyle Beliefs and Healthy Lifestyle Behaviors scales. Descriptive statistics described sample characteristics, paired t tests assessed changes over time in the outcomes Personal Wellness Assessment, and Cohen's d determined effect sizes.

Results

62 DVM students completed both surveys. Postintervention, students had significant improvements in depressive symptoms, anxiety, and healthy lifestyle beliefs and behaviors.

Clinical Relevance

Although this study used a small convenience sample of DVM students from a single university, a cognitive-behavioral skills building program demonstrated the ability to decrease rates of depression, anxiety, and suicidal ideation and improve healthy lifestyle beliefs and behaviors. Requiring DVM students to participate in such programming could provide benefit during their professional education and throughout their careers.

Building and evaluating suicide attempt prediction models using risk factors

This study identified risk factors of suicide attempts for the purpose of building prediction models and evaluating their performance. The participants of this secondary data analysis study were 11 671 adults aged 19 years or older. The prediction models consisted of risk factors identified through multiple logistic regression analysis, and performance was analyzed in terms of calibration, discrimination, and clinical usefulness. The risk factors for suicide attempts were suicide plan and suicidal ideation for males, and suicide plan and depression diagnosis for females. The prediction models constructed with these risk factors showed good calibration and discrimination, with over 0.90 of the area under the curves. At the cutoff point of 0.5%, the sensitivity of the full model was 90.9% for males and 82.4% for females. The net benefit was positive at a threshold probability under 30% for males and 40% for females. Given the acceptable performance of the suicide attempt prediction models, they can be used to assess suicide attempt risk and detect the population at high risk in the community at an early stage, with limited human resources.

A meta-study on transcription factor networks in the suicidal brain

There is evidence supporting the presence of brain gene expression differences between suicides and non-suicides. Such differences have been implicated in suicide pathophysiology. However, regulatory factors underlying these gene expression differences have not been fully understood. Therefore, the identification of differences in regulatory mechanisms, i.e., transcriptional factors between suicides and non-suicides is crucial for the understanding of suicide neurobiology. In this study, we conducted a transcription factor network meta-study with freely available data from the prefrontal cortex of suicides and non-suicides with different mental disorders, including major depression disorder, bipolar disorder and schizophrenia, as well as healthy controls. Disorder-specific characteristics of suicides and non-suicides transcription factor networks were detected, i.e., the presence of immune response genes in both suicides and non-suicides with major depression disorder networks. Also, we found the presence of ESR1, which has been implicated to give resilience to social stress, in the non-suicides network but not in the suicides with major depression network. Suicides and non-suicides with bipolar disorder shared only three genes in common: FOS, CRY1 and PER2. In addition, we found a higher number of genes involved in immune response in the non-suicides with bipolar disorder compared to the suicides with bipolar disorder network. The suicides and non-suicides with schizophrenia networks exhibited clear differences, including the presence of circadian cycle genes in the suicides with schizophrenia network and their absence in the non-suicides with schizophrenia network. The results of this study provide insight on the regulatory mechanisms underpinning transcriptional changes in the suicidal brain.

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.