Further evidence of low baseline cortisol levels in suicide attempters

Diminished salivary cortisol response to mental stress predict all-cause mortality in general population

OBJECTIVES

To characterize individuals with a diminished salivary cortisol response to mental stress, assess its association with all-cause mortality, and quantify the mediating effects of the most relevant and modifiable factors to identify potential target for prevention.

METHODS

Data from MIDUS II study with a 16-year follow-up, were used to categorize 1129 participants as responders or non-responders based on the existence of increase in salivary cortisol under mental stress. LASSO-logistics analysis identified the most relevant factors. Cox regression models and restricted cubic splines evaluated the prognostic impact. Further analyses examined the mediating effects of identified factors on prognosis.

RESULTS

After employing Inverse Probability of Treatment Weighting to adjust for demographic differences between groups, individuals with diminished cortisol responses were found to have higher levels of depressive symptoms (p = 0.050), increased inflammation (IL-6, 2.30 [1.41, 3.79] vs. 1.96[1.33, 3.31], p = 0.011), and were less likely to regularly exercise (74.3 % vs. 79.9 %, p = 0.030). IL-6 (OR: 1.25 [1.04, 1.52]，p = 0.021) and regularly exercising (OR 0.71 [0.51, 0.97], p = 0.032) emerged as significant modifiable factors in multivariate analysis. A notable prognostic association of diminished cortisol response with all-cause mortality (HR = 1.33 [1.01-1.76], p = 0.046) was observed, consistent across various subgroups and supported by non-linear model analysis. Approximately 13 % of the mortality risk associated with diminished cortisol response was mediated by increased IL-6 levels (p = 0.043).

CONCLUSION

Diminished salivary cortisol response is linked to an increased risk of all-cause mortality, significantly mediated by elevated IL-6. This study offers a new perspective on prognostic prediction while highlighting potential avenues for intervention.

Suicidality, perceived chronic stress, and stress-induced cortisol changes of individuals with schizophrenia

The associations of suicidality with stress are poorly studied in schizophrenia. The study aimed to determine whether suicidality was correlated with perceived chronic stress and the cortisol fluctuations under stress tasks in schizophrenia. High suicidality was defined as a lifetime history of suicide attempts or suicidal ideation in the past 2 weeks. Individuals with schizophrenia and high suicidality (SZ-HS, n = 59), with low suicidality (SZ-LS, n = 207), and healthy controls (HC, n = 196) finished the Perceived Stress Scale. Then, they participated in an experiment that induced stress using the Paced Auditory Serial Addition Task and the Mirror Tracing Persistence Task. Negative affect was measured at baseline and after finishing each task. The salivary cortisol was collected before-, after 20 min, and after 40 min of the tasks. SZ-HS had elevated perceived stress than SZ-LS and HC. Mixed effect models showed that stress tasks induced cortisol changes in all groups; cortisol of SZ-LS was reduced more than HC, but SZ-HS and SZ-LS did not differ in cortisol fluctuations. SZ-HS and SZ-LS experienced similar negative affect changes during tasks and the difference in withdrawal rates was nonsignificant. SZ-HS had an increased error rate than SZ-LS. In conclusion, suicidality was correlated with high-level perceived stress but did not result in differences in cortisol reactivities under stress tasks. It suggests the inconsistency between appraisal of stress and biological stress system disturbance among SZ-HS compared to SZ-LS.

Network analysis of comorbid depression, suicidality and biomarkers on HPA axis among mood disorder patients to psychiatric emergency services

Rapid assessment and intervention of suicide risk are common and challenging in psychiatric emergency departments (PED). It is unclear whether distinct pathophysiological processes exist among depressive patients with suicidality. This study examined the network structures of biomarkers on Hypothalamic-Pituitary-Adrenal (HPA) axis, such as Adrenocorticotropic hormone (ACTH) and Corticosterone (Cort), as well as suicidality and depressive symptoms in mood disorder patients in PED. Mood disorder patients in PED were assessed with the measurements of suicidality and depressive symptoms, respectively. A network analysis was performed to identify central symptoms and bridge symptoms of this network and their links to ACTH and Cort. Network stability was examined using the case-dropping procedure. The Network Comparison Test (NCT) was conducted to evaluate whether network characteristics differed by gender. A total of 1815 mood disorder patients were recruited. The prevalence of SI was 31.2% (95% CI: 28.15-34.21%), SP was 30.4% (95% CI: 27.39-33.41%), SA was 30.62% (95% CI: 27.61-33.64%) among psychiatric outpatients. The mean score of HAMD-24 was 13.87 ± 8.02. Network analysis revealed that 'Somatic anxiety' had the highest expected centrality, followed by 'Hopelessness' and 'Suicide attempt'. 'Corticosterone' and 'Retardation' may be the main bridge symptoms between depressive symptoms and the suicidality community. The network model showed a high degree of stability. Gender did not significantly influence the network structure. The central symptoms and key bridge symptoms identified could be potential targets for interventions of the HPA axis, which is designed for regular screening of a range of suicidal activity. In the light of this, timely treatment should be provided for psychiatric emergency care.

Fish and chips: Using machine learning to estimate the effects of basal cortisol on fish foraging behavior

Foraging is an essential behavior for animal survival and requires both learning and decision-making skills. However, despite its relevance and ubiquity, there is still no effective mathematical framework to adequately estimate foraging performance that also takes interindividual variability into account. In this work, foraging performance is evaluated in the context of multi-armed bandit (MAB) problems by means of a biological model and a machine learning algorithm. Siamese fighting fish (Betta splendens) were used as a biological model and their ability to forage was assessed in a four-arm cross-maze over 21 trials. It was observed that fish performance varies according to their basal cortisol levels, i.e., a reduced average reward is associated with low and high levels of basal cortisol, while the optimal level maximizes foraging performance. In addition, we suggest the adoption of the epsilon-greedy algorithm to deal with the exploration-exploitation tradeoff and simulate foraging decisions. The algorithm provided results closely related to the biological model and allowed the normalized basal cortisol levels to be correlated with a corresponding tuning parameter. The obtained results indicate that machine learning, by helping to shed light on the intrinsic relationships between physiological parameters and animal behavior, can be a powerful tool for studying animal cognition and behavioral sciences.

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.

Association of insomnia phenotypes based on polysomnography-measured sleep duration with suicidal ideation and attempts

OBJECTIVE

To assess the association of insomnia phenotypes, being insomnia with short sleep duration (ISSD) and insomnia with normal sleep duration (INSD), with suicidality in a randomly selected population-based sample.

METHODS

Data were analyzed from the Penn State Adult Cohort. Participants (N = 1741, 52.5 years, 57.4% female) were randomly recruited from the general population between January 1990 through March 1999 and mortality data were available through December 2018. Insomnia symptoms were defined as self-reports of moderate-to-severe difficulties initiating or maintaining sleep, early morning awakening and non-restorative sleep, or having chronic insomnia (n = 719). Short sleep duration was defined as <6 hours of in-lab polysomnography-measured sleep duration (n = 879). Suicidality (SAI; n = 102) was ascertained by a lifetime history of suicidal ideation (SI; n = 84), suicide attempts (SA; n = 48) or death by suicide (DBS; n = 10).

RESULTS

Compared to normal sleepers who slept ≥6 hours, participants with ISSD and INSD were associated with 1.72-fold and 2.22-fold increased odds of SAI, respectively; these associations were significant for SI, with 2.09-fold and 2.24-fold increased odds, respectively, but not for SA, after adjusting for physical and mental health comorbidities. ISSD and INSD differed in SAI age of onset and hospitalizations after SA.

CONCLUSIONS

The results of this cohort study suggest that both INSD and ISSD phenotypes are associated with increased suicidal ideation, while the INSD phenotype has an earlier age of onset and is more likely to experience hospitalizations after attempting suicide. These results highlight the importance of targeting insomnia symptoms to help prevent suicide.

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.

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.

Investigating Predictive Factors of Suicidal Re-attempts in Adolescents and Young Adults After a First Suicide Attempt, a Prospective Cohort Study. Study Protocol of the SURAYA Project

INTRODUCTION

Suicide is the fourth leading cause of death in youth. Previous suicide attempts are among the strongest predictors of future suicide re-attempt. However, the lack of data and understanding of suicidal re-attempt behaviors in this population makes suicide risk assessment complex and challenging in clinical practice. The primary objective of this study is to determine the rate of suicide re-attempts in youth admitted to the emergency department after a first suicide attempt. The secondary objectives are to explore the clinical, socio-demographic, and biological risk factors that may be associated with re-attempted suicide in adolescents and young adults.

METHODS

We have developed a single-center prospective and naturalistic study that will follow a cohort of 200 young people aged 16 to 25 years admitted for a first suicide attempt to the emergency department of Lyon, France. The primary outcome measure will be the incidence rate of new suicide attempts during 3 months of follow-up. Secondary outcomes to investigate predictors of suicide attempts will include several socio-demographic, clinical and biological assessments: blood and hair cortisol levels, plasma pro- and mature Brain-Derived Neurotrophic Factor (BDNF) isoforms proportion, previous infection with toxoplasma gondii, and C-Reactive Protein (CRP), orosomucoid, fibrinogen, interleukin (IL)-6 inflammatory markers.

DISCUSSION

To our knowledge, the present study is the first prospective study specifically designed to assess the risk of re-attempting suicide and to investigate the multidimensional predictive factors associated with re-attempting suicide in youth after a first suicide attempt. The results of this study will provide a unique opportunity to better understand whether youth are an at-risk group for suicide re-attempts, and will help us identify predictive factors of suicide re-attempt risk that could be translated into clinical settings to improve psychiatric care in this population.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier: NCT03538197, first registered on 05/29/2018. The first patient was enrolled 05/22/2018.

Cortisol as a Biomarker of Mental Disorder Severity

Cortisol—the most important steroid hormone with a significant effect on body metabolism—strongly affects peripheral tissues and the central nervous system. Fluctuations in cortisol secretion often accompany psychiatric disorders, and normalization of its levels correlates with improvement in the patient’s health. This indicates that cortisol may be useful as a biological marker that can help determine the likelihood of mental illness, its impending onset, and the severity of symptoms, which is especially important in the face of the increasing prevalence of mental disorders, including those associated with social isolation and anxiety during the COVID-19 pandemic. This publication reviews recent reports on cortisol levels in healthy participants and shows the current state of knowledge on changes in the levels of this hormone in people at risk for depression, bipolar disorder, and psychosis. It shows how people with psychiatric disorders react to stressful situations and how the applied therapies affect cortisol secretion. The influence of antidepressants and antipsychotics on cortisol levels in healthy people and those with mental disorders is also described. Finally, it reviews publications on the patterns of cortisol secretion in patients in remission.

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).

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.

Baseline cortisol predicts drunkorexia in female but not male college students

"Drunkorexia" or compensatory eating behaviors in response to alcohol consumption, resembles a subclinical eating disorder, and is a current public health concern. Eating disorders and alcohol abuse are associated with dysfunction of the hypothalamic-pituitary-adrenal axis (HPA). One index of HPA function is cortisol. As causes of drunkorexia remain elusive, the present study examined cortisol function as it relates to drunkorexia. Participants:n = 73 (49 women) college students. Method: Participants provided daytime saliva samples for cortisol analyses prior to completing an online survey measuring alcohol consumption, drunkorexia, and alcohol problems as measured by the Rutgers Alcohol Problem Index (RAPI). Results: Multiple regressions indicated that baseline cortisol significantly positively correlated with drunkorexia behaviors in women but not men. Higher baseline cortisol and aspects of drunkorexia related to alcohol problems. Conclusion: Programs educating about stress management and health risks of drunkorexia may decrease engagement in drunkorexia behaviors among college students.

Epigenetics: A missing link between early life stress and depression

Research has suggested a relationship between early life stress, and depression in particular longer episodes of depression with treatment resistant outcomes. However, the underlying mechanisms for this association remain poorly understood. Molecular studies indicate that, in general, the hereditary character of psychiatric disorders are polygenic, multifactorial and highly complex, with innumerable low-effect genetic variants interacting with each other. In addition, the importance of the environment and its interaction with genes has pointed to a fundamental role of epigenetic mechanisms in psychiatric disorders, such as methylation of deoxyribonucleic acid (DNA), alterations, histone actions and regulation of gene expression by non-coding ribonucleic acids (RNAs). This article provides an overview of the interplay of epigenetics, the HPA axis, early life stress and the development of depression. Advances in our knowledge of epigenetics in the context of early life stress and depression provide a new understanding of the genetic influence on psychopathology and could lead to the identification of new targets for clinical intervention.

"It made me feel brighter in myself"- The health and well-being impacts of a residential front garden horticultural intervention

Residential gardens make up 30% of urban space in the UK, yet unlike many other green space typologies, their role in the health and well-being agenda has largely been overlooked. A horticultural intervention introduced ornamental plants to 38 previously bare front gardens (≈ 10 m²) within an economically deprived region of North England, UK. Measures of perceived stress and diurnal cortisol profiles (as an indicator of health status) were taken pre- and post-intervention (over 3 months). Residents reported significant decreases in perceived stress post-intervention. This finding was aligned with a higher proportion of 'healthy' diurnal cortisol patterns post-intervention, suggesting better health status in those individuals. All residents derived one or more reported socio-cultural benefits as a result of the front garden plantings, although overall scores for subjective well-being did not increase to a significant level. Further qualitative data suggested that the gardens were valued for enhancing relaxation, increasing positive emotions, motivation, and pride of place. The results indicate that adding even small quantities of ornamental plants to front gardens within deprived urban communities had a positive effect on an individual's stress regulation and some, but not all, aspects of subjective well-being. The research highlights the importance of residential front gardens to human health and well-being, and thus their contribution to the wider debates around city densification, natural capital and urban planning.

Prevalence of suicidal ideation and suicide attempt in patients with migraine: A systematic review and meta-analysis

BACKGROUND

Suicidality is common in patients with migraine. Here, we performed a systematic review and estimated the prevalence of suicidal ideation (SI) and suicide attempt (SA) in patients with migraine.

METHODS

We searched Pubmed, Embase, Web of Science, Cochrane database library, CINAHL, and PsycINFO for relevant publications. A random-effects model was used to pool the estimates of the prevalence of SI and SA, which were also stratified by the geographical location of the research institutions from the studies included in this meta-analysis.

RESULTS

Fifteen studies involving 2,247,648 participants with migraine were selected. Pooled prevalence estimates of SI and SA were 15.5% [95% confidence interval (CI) 10.4-21.3%] and 3.9% (95% CI 0.9-8.8%), respectively, and the prevalence of SI was higher in Asian countries (21.5%, 95%CI 16.8-26.6%) compared with non-Asian countries (11.0%, 95%CI 6.1-17.2%). Measures of heterogeneity between studies were high for all outcomes (I² = 89-100%), indicating that the substantial between-study heterogeneity in estimated proportions was not attributed to sampling error. The leave-one-out analysis showed that no single study significantly affected the final pooled results.

CONCLUSIONS

This meta-analysis indicated a high prevalence of SI and SA in migraine patients. Thus, it is necessary to design targeted preventive measures for the management of migraine-related suicide.

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.

Hormonal Dynamics Effect of Serum Insulin-Like Growth Factor I and Cortisol/Dehydroepiandrosterone Sulfate Ratio on Symptom Severity of Major Depressive Disorder

BACKGROUND

Insulin-like growth factor I (IGF-I) is a neurotrophic factor produced by the hypothalamic-pituitary-somatotropic axis and is considered a potential contributor to the pathology of major depressive disorder (MDD). Although it is known that the hypothalamic-pituitary-adrenal axis and cortisol are involved in the pathology of MDD, the association with dehydroepiandrosterone sulfate (DHEAS) remains unclear. The current study sought to clarify the relationship between these hormones and the pathology of MDD.

METHODS

Subjects were 91 Japanese patients with a diagnosis of MDD. Serum IGF-I, cortisol, and DHEAS were measured. Samples were taken before breakfast after overnight fasting. Depressive symptoms were assessed using the Hamilton Rating Scale for Depression (HAM-D).

RESULTS

Subjects included 59 men and 32 women with an average age of 44.1 ± 13.1 years (mean ± SD). The blood IGF-I level was 152.0 ± 50.0 ng/mL, the cortisol level was 10.1 ± 4.6, and the DHEAS level was 201.3 ± 112.7 μg/dL. The mean HAM-D score was 13.9 ± 9.0. Serum IGF-I levels were not correlated with cortisol. Higher IGF-I, cortisol, and cortisol/DHEAS ratios were associated with higher HAM-D scores (adjusted R = 0.240, P < 0.001), and higher IGF-I and cortisol were associated with higher melancholic or suicide subscores (adjusted R = 0.200, P < 0.001; adjusted R = 0.273, P < 0.001).

CONCLUSIONS

Our findings suggest that hormonal dysregulation of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-somatotropic axes may be related to the symptom severity of MDD, melancholia, and suicide-related factors.

The role of childhood maltreatment in cortisol in the hypothalamic-pituitary-adrenal (HPA) axis in methamphetamine-dependent individuals with and without depression comorbidity and suicide attempts

BACKGROUND

The hypothalamic-pituitary-adrenal (HPA) axis dysregulation which was found to have an important role in the pathophysiology of depression, suicide, and substance dependence, may be influenced by childhood maltreatment (CM). The present study aimed to investigate the relationship between CM and cortisol changes in methamphetamine-dependent individuals.

METHODS

In a cross-sectional study, methamphetamine-dependent individuals (n = =195) with or without both comorbid major depressive disorder (MDD) and a history of suicide attempts were selected and completed the Childhood Trauma Questionnaire-Short Form (CTQ-SF), the Beck Scale for Suicide Ideation (BSSI), and the Beck Depression Inventory-II (BDI-II). To assess cortisol levels, saliva samples were collected at six time intervals for two consecutive days.

RESULTS

A history of CM significantly predicted wake-up cortisol level, cortisol awakening response (CAR), and diurnal cortisol slope. Methamphetamine-dependent individuals with both MDD and lifetime suicide attempts had higher CM and higher cortisol levels with a blunted diurnal cortisol slope than individuals who were merely methamphetamine-dependent. Individuals with high CM showed higher cortisol levels with a blunted diurnal slope than those with low or without CM.

LIMITATIONS

Cross-sectional data and use of self-report scales, especially retrospective measurements (e.g., the CTQ-SF), were important limitations of this study.

CONCLUSION

Findings suggest that methamphetamine-dependent individuals with adverse psychological factors such as CM, MDD, and suicide attempts may show dysregulation in biological factors including cortisol level. In addition, CM and its effects on cortisol in the HPA axis may emerge as important factors regarding psychopathological use of methamphetamine.

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.

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.

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.

Social isolation as a promising animal model of PTSD comorbid suicide: neurosteroids and cannabinoids as possible treatment options

Post-traumatic stress disorder (PTSD) is a psychiatric condition characterized by drastic alterations in mood, emotions, social abilities and cognition. Notably, one aspect of PTSD, particularly in veterans, is its comorbidity with suicide. Elevated aggressiveness predicts high-risk to suicide in humans and despite the difficulty in reproducing a complex human suicidal behavior in rodents, aggressive behavior is a well reproducible behavioral trait of suicide. PTSD animal models are based on a peculiar phenotype, including exaggerated fear memory and impaired fear extinction associated with neurochemical dysregulations in the brain circuitry regulating emotion. The endocannabinoid and the neurosteroid systems regulate emotions and stress responses, and recent evidence shows these two systems are interrelated and critically compromised in neuropsychiatric disorders. For instance, levels of the neurosteroid, allopregnanolone, as well as those of the endocannabinoids, anandamide and its congener, palmitoylethanolamide are decreased in PTSD. Similarly, the endocannabinoid system and neurosteroid biosynthesis are altered in suicidal individuals. Selective serotonin reuptake inhibitors (SSRIs), the only FDA-approved treatments for PTSD, fail to help half of the treatment-seeking patients. This highlights the need for developing biomarker-based efficient therapies. One promising alternative to SSRIs points to stimulation of allopregnanolone biosynthesis as a treatment and a valid end-point to predict treatment response in PTSD patients. This review highlights running findings on the role of the endocannabinoid and neurosteroid systems in PTSD and suicidal behavior both in a preclinical and clinical perspective. A specific focus is given to predictive PTSD/suicide animal models. Ultimately, we discuss the idea that disruption of neurosteroid and endocannabinoid biosynthesis may offer a novel promising biomarker axis to develop new treatments for PTSD and, perhaps, suicidal behavior.

Salivary Electrochemical Cortisol Biosensor Based on Tin Disulfide Nanoflakes

Cortisol, a steroid hormone, is secreted by the hypothalamic-pituitary-adrenal system. It is a well-known biomarker of psychological stress and is hence known as the "stress hormone." If cortisol overexpression is prolonged and repeated, dysfunction in the regulation of cortisol eventually occurs. Therefore, a rapid point-of-care assay to detect cortisol is needed. Salivary cortisol electrochemical analysis is a non-invasive method that is potentially useful in enabling rapid measurement of cortisol levels. In this study, multilayer films containing two-dimensional tin disulfide nanoflakes, cortisol antibody (C-M_ab), and bovine serum albumin (BSA) were prepared on glassy carbon electrodes (GCE) as BSA/C-M_ab/SnS₂/GCE, and characterized using electrochemical impedance spectroscopy and cyclic voltammetry. Electrochemical responses of the biosensor as a function of cortisol concentrations were determined using cyclic voltammetry and differential pulse voltammetry. This cortisol biosensor exhibited a detection range from 100 pM to 100 μM, a detection limit of 100 pM, and a sensitivity of 0.0103 mA/Mcm² (R² = 0.9979). Finally, cortisol concentrations in authentic saliva samples obtained using the developed electrochemical system correlated well with results obtained using enzyme-linked immunosorbent assays. This biosensor was successfully prepared and used for the electrochemical detection of salivary cortisol over physiological ranges, based on the specificity of antibody-antigen interactions.

Adolescent Suicide as a Failure of Acute Stress-Response Systems

Suicide is the second leading cause of death worldwide for adolescents. Despite decades of research on correlates and risk factors for adolescent suicide, we know little about why suicidal ideation and behavior frequently emerge in adolescence and how to predict, and ultimately prevent, suicidal behavior among youths. In this review, we first discuss knowledge regarding correlates, risk factors, and theories of suicide. We then review why adolescence is a period of unique vulnerability, given changing biology and social network reorganization. Next, we present a conceptual model through which to interpret emerging findings in adolescent suicide research. We suggest that a promising area for future research is to examine adolescent suicide as a failure of biological responses to acute stress in the proximal moments of a suicidal crisis. After reviewing initial evidence for this conceptualization, we review future directions for studies on adolescent suicide.

Biological responses to acute stress and suicide: A review and opportunities for methodological innovation

Purpose of Review

While rates of other medical illnesses have declined over the past several decades, rates of suicide have increased, particularly among adolescents. Prior research on biological underpinnings of suicide risk has remained limited. In this review, we describe a recent model conceptualizing suicide as a failure of biological responses to acute stress. According to this model, youth who fail to mount an adaptive stress response following exposure to a stressor are at acute risk for suicide.

Recent Findings

Although much more research is needed, early evidence suggests that abnormal biological responses to acute stress, such as altered autonomic nervous system activity and altered hypothalamic-pituitary-adrenal axis function, may underlie risk for suicide, particularly during the transition to adolescence.

Summary

Overall, initial evidence supports a link between biological responses to acute stress and suicide risk. However, future work that incorporates makers of other biological and environmental systems will sharpen our understanding of who is at suicide risk and when this risk is highest.

Impulsivity and Saliva Cortisol in Patients with Suicide Attempt and Controls

OBJECTIVES

The objective of this study was to prove concepts in the characterization of suicidal patients and the possible usefulness of those markers to potentially identify patients with a higher risk for suicidality.

METHODS

Patients with a recent suicide attempt were compared with patients suffering from depression, adjustment disorder, anxiety, or eating disorders without suicidality, healthy controls and remitted patients with a history of at least 1 suicide attempt (≥1 year). We analyzed impulsivity (Barratt Impulsivity Scale, BIS) and saliva cortisol concentrations.

RESULTS

Independently of suicidality and disease state patients display higher BIS scores than healthy controls. Saliva cortisol levels tend to be higher in patients in the acute disease state than in remitted patients and healthy controls.

CONCLUSIONS

Saliva cortisol may be a useful marker that reveals alterations in nonsuicidal patients suffering from depression, adjustment disorder, anxiety, or eating disorders who might be at risk.

Toward subtyping of suicidality: Brief suicidal ideation is associated with greater stress response

BACKGROUND

Suicide is a heterogeneous phenomenon, and thus defining more homogeneous subgroups may help in understanding its underlying biology and ultimately in its prevention. Suicidal ideation is far more common than suicidal behavior and predicts future suicide attempts. Hypothalamic-pituitary-adrenal (HPA)-axis reactivity has been implicated in individuals with suicidal ideation but findings are mixed with some studies showing increased and others demonstrating decreased reactivity. This suggests that dysregulation of HPA-axis is related to a specific character of suicidal ideation. We hypothesized that individuals with brief suicidal ideation are more stress responsive than those with longer/continuous ideation.

METHODS

Thirty-five individuals with major depressive disorder (MDD) and 23 healthy volunteers (HVs), aged 18-65 years, underwent the Trier Social Stress Test (TSST). Salivary cortisol was measured at 6 time-points before and during TSST. Total severity and duration of current suicidal ideation were assessed using the Beck Scale for Suicidal Ideation (SSI). Brief suicidal ideators (N = 18), longer/continuous ideators (N = 17) and HVs were compared regarding cortisol response, baseline cortisol and total output.

RESULTS

Participants with brief suicidal ideation had greater cortisol response compared to those with longer/continuous ideation and HVs, even after controlling for relevant covariates. However, total SSI score was not associated with cortisol response. Baseline cortisol and total output were not related to overall severity or duration of suicidal ideation.

LIMITATIONS

The cross-sectional design and modest sample limit generalizability of the results.

CONCLUSIONS

Hyper-responsiveness of HPA-axis to social stress is associated with brief suicidal ideation, possibly defining a pathway for exploring the biological subtyping of suicidal individuals.

Association between migraine and suicidal behavior among Ethiopian adults

BACKGROUND

Despite the significant impact of migraine on patients and societies, few studies in low- and middle-income countries (LMICs) have investigated the association between migraine and suicidal behavior. The objective of our study is to examine the extent to which migraines are associated with suicidal behavior (including suicidal ideation, plans, and attempts) in a well-characterized study of urban dwelling Ethiopian adults.

METHODS

We enrolled 1060 outpatient adults attending St. Paul hospital in Addis Ababa, Ethiopia. Standardized questionnaires were used to collect data on socio-demographics, and lifestyle characteristics. Migraine classification was based on the International Classification of Headache Disorders-2 diagnostic criteria. The Composite International Diagnostic Interview (CIDI) was used to assess depression and suicidal behaviors (i.e. ideation, plans and attempts). Multivariable logistic regression models were used to estimate adjusted odds ratio (AOR) and 95% confidence intervals (95% CIs).

RESULTS

The prevalence of suicidal behavior was 15.1%, with a higher suicidal behavior among those who had migraines (61.9%). After adjusting for confounders including substance use and socio-demographic factors, migraine was associated with a 2.7-fold increased odds of suicidal behavior (AOR = 2.7; 95% CI 1.88-3.89). When stratified by their history of depression in the past year, migraine without depression was significantly associated with suicidal behavior (AOR: 2.27, 95% Cl: 1.49-3.46). The odds of suicidal behavior did not reach statistical significance in migraineurs with depression (AOR: 1.64, 95% CI: 0.40-6.69).

CONCLUSION

Our study indicates that migraine is associated with increased odds of suicidal behavior in this population. Given the serious public health implications this has, attention should be given to the treatment and management of migraine at a community level.

Effects of childhood trauma on cortisol levels in suicide attempters and ideators

OBJECTIVES

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 for suicide. Recent evidence has indicated that blunted cortisol reactivity to stress is associated with suicidal behavior. The current study investigated whether childhood trauma was associated with blunted cortisol reactivity to a laboratory stressor and resting cortisol levels in suicide attempters and ideators.

METHODS

160 Participants were recruited and grouped according to history of previous suicidal attempt, suicidal ideation or as control participants. Participants completed background questionnaires, including the Childhood Trauma Questionnaire, before completing a laboratory stress task. Cortisol levels were assessed at rest and during the stress task.

RESULTS

The highest levels of childhood trauma were reported in those who had attempted suicide (78.7%), followed by those who thought about suicide (37.7%) and then those with no suicidal history (17.8%). Moreover, regression analyses showed that childhood trauma was a significant predictor of blunted cortisol reactivity to stress and resting cortisol levels, such that higher levels of trauma were associated with lower cortisol levels in those with a suicidal history. Family history of suicide did not interact with the effects of childhood trauma on cortisol levels.

CONCLUSIONS

These results indicate that childhood trauma is associated with blunted HPA axis activity in vulnerable populations in adulthood. The challenge for researchers is to elucidate the precise causal mechanisms linking trauma, cortisol and suicide risk and to investigate whether the effects of childhood trauma on cortisol levels are amendable to psychological intervention.

Impaired glucocorticoid-mediated HPA axis negative feedback induced by juvenile social isolation in male rats

We previously demonstrated that socially isolated rats at weaning showed a significant decrease in corticosterone and adrenocorticotropic hormone (ACTH) levels, associated with an enhanced response to acute stressful stimuli. Here we shown that social isolation decreased levels of total corticosterone and of its carrier corticosteroid-binding globulin, but did not influence the availability of the free active fraction of corticosterone, both under basal conditions and after acute stress exposure. Under basal conditions, social isolation increased the abundance of glucocorticoid receptors, while it decreased that of mineralocorticoid receptors. After acute stress exposure, socially isolated rats showed long-lasting corticosterone, ACTH and corticotrophin releasing hormone responses. Moreover, while in the hippocampus and hypothalamus of group-housed rats glucocorticoid receptors expression increased with time and reached a peak when corticosterone levels returned to basal values, in socially isolated rats expression of glucocorticoid receptors did not change. Finally, social isolation also affected the hypothalamic endocannabinoid system: compared to group-housed rats, basal levels of anandamide and cannabinoid receptor type 1 were increased, while basal levels of 2-arachidonoylglycerol were decreased in socially isolated rats and did not change after acute stress exposure. The present results show that social isolation in male rats alters basal HPA axis activity and impairs glucocorticoid-mediated negative feedback after acute stress. Given that social isolation is considered an animal model of several neuropsychiatric disorders, such as generalized anxiety disorder, depression, post-traumatic stress disorder and schizophrenia, these data could contribute to better understand the alterations in HPA axis activity observed in these disorders.

Biomarkers of Suicide Attempt Behavior: Towards a Biological Model of Risk

PURPOSE OF REVIEW

The rising suicide rate in the USA will not be reversed without improved risk assessment and prevention practices. To date, the best method for clinicians to assess a patient's risk for suicide is screening for past suicide attempts in the patient and their family. However, neuroimaging, genomic, and biochemical studies have generated a body of findings that allow description of an initial heuristic biological model for suicidal behavior that may have predictive value.

RECENT FINDINGS

We review studies from the past 3 years examining potential biological predictors of suicide attempt behavior. We divide findings into two major categories: (1) structural and functional brain imaging findings and (2) biochemical and genomic findings encompassing several systems, including major neurotransmitters (serotonin, catecholamines, GABA, and glutamate), the hypothalamic pituitary adrenal (HPA) axis, the inflammasome, lipids, and neuroplasticity. The biomarkers that appear promising for assessing suicide risk in clinical settings include indices of serotonergic function, inflammation, neuronal plasticity, and lipids.

Blunted HPA axis activity prior to suicide attempt and increased inflammation in attempters

BACKGROUND

Hypothalamic-Pituitary-Adrenal (HPA) axis dysregulation is associated with increased risk for suicidal behavior. However, it is not clear whether such dysregulation exists prior to or is a consequence of attempt. Studies also show an activation of inflammatory responses in suicidal behavior but often combine attempters with those with ideation.

METHODS

The sample consisted of psychiatric inpatients, aged 15-30 years, admitted for suicide attempt (SA, n=38), inpatients admitted for suicidal ideation with no prior history of attempts (SI, n=40), and healthy controls (n=37). We compared SA, SI, and controls on hair cortisol concentrations (HCC), which provides retrospective levels of cortisol and thus prior to the attempt in SA. We also compared them on the expression of genes in the HPA axis and inflammatory pathways previously implicated in suicidal behavior (GR or NR3C1, SKA2, FKBP5, IL-1β, TNF-α); plasma C-Reactive Protein (CRP); and cellular measures of glucocorticoid receptor (GR) sensitivity and stimulated production of IL-6.

RESULTS

We found lower HCC [β=-0.55, 95% CI (-0.96, -0.13), p=0.01, ES=-0.54] in first-time SA compared to SI and controls. In addition, SA showed lower GR or NR3C1 (α isoform) mRNA [β=-5.11, 95% CI (-10.9, 0.73), p=0.09, ES=-0.46], higher CRP [β=0.94, 95% CI (-0.004, 1.9), p=0.05, ES=0.60], and higher TNF-α mRNA [β=26.4, 95% CI (7.7, 45.2), p=0.006, ES=0.73].

CONCLUSIONS

This is the first study to differentiate youth who attempt suicide from those with suicidal ideation on HCC and to show that low HCC precedes suicide attempt. Suicide attempters also showed a distinct biological profile on several markers in both the HPA axis and inflammatory pathways. Future longitudinal studies are needed to examine the ability of these biomarkers to predict suicidal behavior.

Cortisol reactivity and suicidal behavior: Investigating the role of hypothalamic-pituitary-adrenal axis responses to stress in suicide attempters and ideators

Every 40s a person dies by suicide somewhere in the world. The causes of suicidal behavior are not fully understood. Dysregulated hypothalamic-pituitary-adrenal (HPA) axis activity, as measured by cortisol levels, is one potential risk factor. The current study aimed to investigate whether cortisol reactivity to a laboratory stress task differentiated individuals who had previously made a suicide attempt from those who had thought about suicide (suicide ideators) and control participants. One hundred and sixty participants were recruited to a previous attempt, a suicidal ideation or a control group. Participants completed background questionnaires before completing the Maastricht Acute Stress Test (MAST). Cortisol levels were assessed throughout the stress task. Measures of suicide behavior were measured at baseline, 1 month and 6 month follow-up. Participants who had made a previous suicide attempt exhibited significantly lower aggregate cortisol levels during the MAST compared to participants in the control group; suicide ideators were intermediate to both groups. This effect, however, was driven by participants who made an attempt within the past year, and to some degree by those with a family history of attempt. Participants who made a suicide attempt and had a family history of suicide exhibited the lowest levels of cortisol in response to stress. Finally, lower levels of cortisol in response to the MAST were associated with higher levels of suicidal ideation at 1-month follow-up in the suicide attempter group. These results are consistent with other findings indicating that blunted HPA axis activity is associated with some forms of suicidal behavior. The challenge for researchers is to elucidate the precise causal mechanisms linking stress, cortisol and suicide risk.