How lipids may affect risk for suicidal behavior

Elevated SCN11A concentrations associated with lower serum lipid levels in patients with major depressive disorder

The pathogenesis of major depressive disorder (MDD) involves lipid metabolism. Our earlier research also revealed that MDD patients had much lower total cholesterol (TC) concentrations than healthy controls (HCs). However, it is still unclear why TC decreased in MDD. Here, based on the Ingenuity Knowledge Base's ingenuity pathway analysis, we found that sodium voltage-gated channel alpha subunit 11A (SCN11A) might serve as a link between low lipid levels and MDD. We analyzed the TC levels and used ELISA kits to measure the levels of SCN11A in the serum from 139 MDD patients, and 65 HCs to confirm this theory and explore the potential involvement of SCN11A in MDD. The findings revealed that TC levels were considerably lower and SCN11A levels were remarkably increased in MDD patients than those in HCs, while they were significantly reversed in drug-treatment MDD patients than in drug-naïve MDD patients. There was no significant difference in SCN11A levels among MDD patients who used single or multiple antidepressants, and selective serotonin reuptake inhibitors or other antidepressants. Pearson correlation analysis showed that the levels of TC and SCN11A were linked with the Hamilton Depression Rating Scales score. A substantial association was also found between TC and SCN11A. Moreover, a discriminative model made up of SCN11A was discovered, which produced an area under a curve of 0.9571 in the training set and 0.9357 in the testing set. Taken together, our findings indicated that SCN11A may serve as a link between low lipid levels and MDD, and showed promise as a candidate biomarker for MDD.

Serum lipids as predictive markers for death by suicide

Serum lipid levels have been associated with an increased risk of suicidal behaviors. This retrospective cohort study aimed to investigate the association between serum lipid levels and death by suicide among suicide attempters according to sex. Suicide attempters visiting emergency departments between 2007 and 2011 were followed up until the date of all-cause death or December 31, 2012. Sex-stratified Cox proportional hazards regression and competing risk models were constructed to obtain the hazard ratios (HR) of serum lipid measures and suicide. For each significant lipid variable in the final models, Kaplan-Meier survival analysis and cumulative incidence function (CIF) were employed to compare the time to suicide between the high- and low-lipid groups based on the best cutoff point from the receiver operating characteristic curve. In 408 female attempters (65.8 %), the HR in the Cox regression model and subdistribution HR in the competing risk model for increased total cholesterol (TC) were 0.968 and 0.970, respectively. In the Kaplan-Meier survival analysis and CIF, increased death by suicide was demonstrated in the low-TC group (< 165 mg/dL). Lower serum TC levels among female suicide attempters may predict suicide. More careful monitoring is warranted in women with lower TC levels who recently attempted suicide.

Serotonin Signaling through Lipid Membranes

Serotonin (5-HT) is a vital modulatory neurotransmitter responsible for regulating most behaviors in the brain. An inefficient 5-HT synaptic function is often linked to various mental disorders. Primarily, membrane proteins controlling the expression and activity of 5-HT synthesis, storage, release, receptor activation, and inactivation are critical to 5-HT signaling in synaptic and extra-synaptic sites. Moreover, these signals represent information transmission across membranes. Although the lipid membrane environment is often viewed as fairly stable, emerging research suggests significant functional lipid-protein interactions with many synaptic 5-HT proteins. These protein-lipid interactions extend to almost all the primary lipid classes that form the plasma membrane. Collectively, these lipid classes and lipid-protein interactions affect 5-HT synaptic efficacy at the synapse. The highly dynamic lipid composition of synaptic membranes suggests that these lipids and their interactions with proteins may contribute to the plasticity of the 5-HT synapse. Therefore, this broader protein-lipid model of the 5-HT synapse necessitates a reconsideration of 5-HT's role in various associated mental disorders.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Apolipoproteins and Suicide: A Potential Psychiatric Biomarker

Every year around 800,000 people commit suicide, this represents one death every 40 s. In the search for possible biological biomarkers associated with suicide and/or psychiatric disorders, serum cholesterol levels have been extensively explored. Several studies indicate that cholesterol and associated proteins, especially apolipoproteins (Apos), may play an important role in the diagnosis, prognosis, and susceptibility of suicidal behavior. Here, we describe the current knowledge and findings in the relationship between apolipoproteins and suicide.HIGHLIGHTSThis is the first systematic review of Apos in relation to suicidal behavior.Dysregulations of Apos expression has been observed in patients with suicidal behavior.Apos seem to be associated with cognitive dysfunction in suicide attempters.ApoE is a potential biomarker regarding suicidal behavior.

Prevalence and influencing factors of suicide in first-episode and drug-naive young major depressive disorder patients with impaired fasting glucose: a cross-sectional study

Background

An association exists between major depression disorder (MDD), suicide attempts, and glucose metabolism, but suicide attempts in young MDD patients with comorbid impaired fasting glucose (IFG) have been less well studied. The purpose of this study was to examine the prevalence and risk factors for suicide attempts in young, first-episode, drug-naive (FEDN) MDD patients with comorbid IFG.

Methods

We recruited 917 young patients with FEDN MDD, 116 of whom were judged to have combined IFG because their blood glucose was >6.0. We collected anthropological and clinical data on all of them. The Hamilton Depression Scale (HAMD) score, the Hamilton Anxiety Scale (HAMA) score and the Positive and Negative Syndrome Scale (PANSS) positive subscale score were used to assess their clinical symptoms. Blood glucose, plasma thyroid function and lipid indicators were measured.

Results

The prevalence of suicide attempts in young MDD patients with IFG was 32.8% (38/116). Furthermore, among young MDD patients with comorbid IFG, suicide attempters had more severe depression and anxiety symptoms, more comorbid psychotic symptom, higher levels of antibody of thyroid stimulating hormone and thyroid peroxidases (TPOAb), and more severe lipid metabolism disorders than those without suicide attempts. In addition, HAMA scores and TPOAb were independently associated with suicide attempts in young patients with FEDN MDD.

Conclusion

Our study suggests that young MDD patients with IFG have a high rate of suicide attempts. Some clinical symptoms and thyroid function parameters may be the risk factor for suicide attempts in young MDD patients with impaired glucose metabolism.

Potential Suicide Prophylactic Activity by the Fish Oil Metabolite, 4-Hydroxyhexenal

Low levels of n-3 poly-unsaturated fatty acids (n-3 PUFAs) and high levels of n-6 PUFAs in the blood circulation are associated with an increased risk for suicide. Clinical studies indicate that docosahexaenoic acid (DHA, a n-3 PUFA found in fish-oil) displays protective effects against suicide. It has recently been proposed that the activation of the transcription factor NRF2 might be the pharmacological activity that is common to current anti-suicidal medications. Oxidation products from fish oil, including those from DHA, are electrophiles that reversibly bind to a protein ‘KEAP1’, which acts as the molecular inhibitor of NRF2 and so indirectly promotes NRF2-transcriptional activity. In the majority of publications, the NRF2-stimulant effect of DHA is ascribed to the metabolite 4-hydroxyhexenal (4HHE). It is suggested to investigate whether 4HHE will display a therapeutically useful anti-suicidal efficacy.

Changes in the association between the traditional Japanese diet score and suicide rates over 26 years: A global comparative study

BACKGROUND

This study examined the global association between the Traditional Japanese Diet Score and suicide rate.

METHODS

Average food supply and energy supply by country were obtained from the Food and Agriculture Organization of the United Nations Statistics Division database (FAOSTAT). Traditional Japanese Diet Score (TJDS) was calculated from food group classifications. Age-standardized suicide rates per 100,000 people by country were obtained from the Global Burden of Disease 2017 database. The 26-year associations between TJDS and suicide rates were examined controlling for covariates using a mixed-effects model in 138 countries with populations of 1 million or greater.

RESULTS

A significant negative association was found in the analysis of the relationship between TJDS and the prevalence of suicide [β (se) = -0.126 (0.031), p < 0.001]. The interaction term between TJDS and year was also significant [β (se) = -0.011 (0.003), p < 0.001]. The change in the effect of TJDS on suicide rates by year was examined. The effect of TJDS was not significant from 1991 to 1999 but became significant after 2000; the slope of the TJDS to suicide rate in 2017 was -0.270 (95% confidence interval -0.382, -0.169, p < 0.001).

LIMITATIONS

This was a national ecological study and did not consider individual differences in sex, age, and lifestyle.

CONCLUSIONS

TJDS may be is a protective factor for depression, which may prevent suicide. The association between TJDS and suicide rates became stronger over time and was inversely associated with suicide rates after 2000.

A candidate biological network formed by genes from genomic and hypothesis-free scans of suicide

Information about genes and the biology of suicidal behavior (SB) is noisy due to heterogenous outcomes (suicide attempts or deaths), as well as many different genes and overlapping biological processes implicated. One approach to test the unbiased biological coherence of disease genes, is to use genes from hypothesis-free genetic scans and to investigate if they aggregate close to each other in cellular gene and protein interaction networks ("interactomes"). Therefore, we used network methods to study the biological coherence among genes (n = 229) from genome-wide association studies (GWAS) and whole exome sequencing (WES) of suicide outcome. Results showed that the suicide GWAS+WES genes has significant aggregation in three major interactome database assemblies, a hallmark of biological similarity and increased likelihood of being involved in the same outcome (suicide). This pinpointed e.g. genes on chromosome 19, which are also associated with lipid metabolism, schizophrenia and bipolar disorder. We identified a subset of GWAS+WES "core" genes (n = 54) which are the most proximal to each other in the context of three interactome assemblies, and present a candidate network module of suicide which is specific for nervous system tissues. The n = 54 most proximal "core" genes showed overrepresentation of synaptic and nervous system development genes, as well as network paths to other SB genes having increased evidence diversity. Overall, results suggested the existence of a coherent biology in suicide outcome and provide unbiased biological support concerning links to other SB genes, as well as e.g. bipolar disorder, excitatory/inhibitory function and ketamine treatment in SB.

Possible Association of Cholesterol as a Biomarker in Suicide Behavior

Suicides and suicidal behavior are major causes of mortality and morbidity in public health and are a global problem. Various authors have proposed changes in lipid metabolism (total cholesterol decrease) as a possible biological marker for suicidal behavior. The objective of this study was to review the studies that have demonstrated a relationship between serum cholesterol levels and suicidal behavior and to describe the possible pathophysiological mechanisms that associate changes in cholesterol concentration and suicidal behavior. Relevant literature related to serum cholesterol levels and suicidal behavior was identified through various database searches. The data from the existing literature present the findings that relate low cholesterol levels and possible pathophysiological mechanisms (neuroinflammation, serotonergic neurotransmission), genes related to cholesterol synthesis, pharmacological treatments that alter lipid metabolism and the possible participation in suicidal behavior. Nevertheless, future research is required to describe how serum cholesterol affects cholesterol metabolism in the CNS to establish and understand the role of cholesterol in suicidal behavior.

Prevalence and correlates of suicidal behaviour among adults in Malawi: a nationally representative cross-sectional survey in 2017

Background

The study aimed to assess the prevalence and associated factors of suicidal behaviour (SB) among adults in Malawi.

Methods

Data were analysed from 4187 persons aged 18–69 years (median age: 32 years) that took part in the nationally representative cross-sectional “2017 Malawi STEPS survey.”

Results

The prevalence of ever suicide attempt was 0.8%, and the prevalence of SB (ideation, plan and/or attempt) in the past year was 7.9% (6.0% among men and 9.6% among women). In adjusted logistic regression analysis, among men, being 30 years and older and having an alcohol family problem were positively and obesity was negatively associated with SB in the past year. Moreover, in univariate analysis, early smoking initiation was positively and not using active transportation was negatively associated with SB in the past year. Among women, having an alcohol family problem, death from suicide of a close family member, having a cardiovascular incident (heart attack, stroke, or angina) and not using active transportation increased the odds of SB in the past year. In addition, in univariate analysis, low systolic blood pressure (< 100 mmHg), not taking antihypertensive medication, and current alcohol use were associated with past year SB.

Conclusion

Almost one in ten participants engaged in SB in the past year and several associated factors were identified that can inform intervention programmes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13033-021-00483-x.

Effectiveness of Complementary and Integrative Approaches in Promoting Engagement and Overall Wellness Toward Suicide Prevention in Veterans

Objective: Suicide is a major public health problem, specifically among U.S. veterans, who do not consistently engage in mental health services, often citing stigma as a barrier. Complementary and Integrative Health (CIH) interventions are promising alternatives in promoting patient engagement and further, they may play a critical role in transitioning people into mental health care. Toward this goal, the Resilience and Wellness Center (RWC) was developed to break through the stigma barrier by addressing risk factors of suicide through multimodal CIH interventions via cohort design, promoting social connectedness and accountability among participants. Design: This is a program evaluation study at a large urban VA medical center, where assessments were evaluated from pre- to post-program completion to determine the effectiveness of an intensive multimodal CIH 4-week group outpatient intervention for suicide prevention. Outcome measures: Primary outcomes measured included group connectedness, severity of depression and hopelessness symptoms, suicidal ideation, sleep quality, and diet. Secondary outcomes included measures of post-traumatic stress disorder (PTSD), generalized anxiety severity stress/coping skills, pain, and fatigue. Results: The RWC showed high participant engagement, with an 84%-95% attendance engagement rate depending on suicide risk history. Data from 15 cohorts (N = 126) demonstrate favorable outcomes associated with participation in this comprehensive program, as evidenced by a reduction in suicidal ideation, depression, and hopelessness, but not sleep quality and diet. In addition, in a subset of veterans with a history of suicidal ideation or attempt, significant improvements were noted in pain, PTSD/anxiety symptoms, and stress coping measures. Conclusions: The RWC shows that an intensive complement of CIH interventions is associated with a significant improvement with high veteran engagement. Findings from this program evaluation study can be used to aid health care systems and their providers in determining whether or not to utilize such multimodal CIH integrated interventions as an effective treatment for at-risk populations as a part of suicide prevention efforts.

Serum Fatty Acid Latent Classes Are Associated With Suicide in a Large Military Personnel Sample

OBJECTIVE

Fatty acids (FAs) are involved in the functioning of biological systems previously associated with suicidal behavior (eg, monoamine signaling and the immune system). We sought to determine (1) whether observed FA levels in a sample of military suicide decedents and living matched controls were consistent with latent classes having distinctive FA profiles and (2) whether those latent classes were associated with suicide and mental health diagnoses.

METHODS

Serum samples from 800 US military suicide decedents who died between 2002 and 2008 and 800 demographically matched living controls were selected at random from a large military serum repository and assayed for 22 different FAs. A latent class cluster analysis was performed using values of 6 FAs previously individually associated with suicide. Once the latent classes were identified, they were compared in terms of suicide decedent proportion, demographic variables, estimated FA enzyme activity, diagnoses, and mental health care usage.

RESULTS

A 6-latent class solution best characterized the dataset. Suicide decedents were less likely to belong to 2 of the classes and more likely to belong to 3 of the classes. The low-decedent classes differed from the high-decedent classes on 9 FAs and on estimated indices of activity for 3 FA enzymes: 14:0, 24:0, 18:1 n-9, 24:1 n-9, 22:5 n-3, 22:6 n-3, 20:2 n-6, 20:4 n-6, 22:5 n-6, elongation of very long chain fatty acids protein 1 (ELOVL1), ELOVL6, and Δ9 desaturase. The FA profiles of the latent classes were consistent with biological abnormalities previously associated with suicidal behavior.

CONCLUSIONS

This study suggests the utility of methods that simultaneously examine multiple FAs when trying to understand their relationship with suicide and psychiatric illness.

High-lethality of suicide attempts associated with platelet to lymphocyte ratio and mean platelet volume in psychiatric inpatient setting

OBJECTIVES

A wide range of potential psychosocial, biological, genetic and environmental factors may interact with each other in determining suicidal behaviours. The aim of this study was to evaluate several biological parameters referred to the complete blood count values in 259 suicide attempters (SA) and 164 non-suicide attempters (control group), according to the lethality of suicidal behaviour.

METHODS

After attempting suicide, subjects were admitted to the emergency ward of the IRCCS Ospedale Policlinico San Martino and later to the section of Psychiatry from 1 January 2014 to 31 June 2019. Socio-demographic and clinical characteristics, as well as blood cells, were collected.

RESULTS

Individuals with high-lethality suicide attempts had a higher number of neutrophils, mean platelet volume, neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, and lower number of lymphocytes relative to both those with low-lethality suicide attempts and control group. After regression analysis, only the mean platelet volume and platelet to lymphocyte ratio resulted associated with a high-lethality suicide attempt (HLSA).

CONCLUSIONS

Our findings provide potential and useful peripheral biological markers able to help clinicians in understanding the complex phenomenon of suicide. However, further studies are needed to confirm the present findings.

Relationships between inflammatory markers and suicide risk status in major depression

Pro-inflammatory status has been implicated in depression and suicidal behaviors. Polyunsaturated fatty acids (PUFAs) and cytokines, two types of inflammatory biomarkers, have been associated with suicide, independent of depression severity. How these biomarkers relate to each other is less clear. We measured plasma phospholipid levels of arachidonic acid (AA%), docosahexaenoic acid (DHA%), and eicosapentaenoic acid (EPA%) as a percentage of total phospholipids, as well as serum interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α), in 80 patients with major depressive disorder (MDD) and 24 healthy controls (HC). Individual PUFA and cytokine species were compared using ANOVA across four suicide risk-stratified groups: 1) highest-risk, recent (within 5 years) suicide attempters (n = 20); 2) high-risk, severe current suicidal ideators (having intent or plan) with no recent attempt history (n = 22); 3) low-risk, current non-ideators who were also lifetime non-attempters (n = 38); and 4) HC (n = 24). None of the participants were enrolled following an acute suicide attempt. Of biomarkers studied, only DHA% (p = 0.012) and IL-1β (p = 0.002) differed between groups. In post-hoc testing, DHA% was lower in attempters than ideators (p = 0.018) or MDD non-ideators (trend level, p = 0.073). IL-1β was lowest in attempters, differentiating them from ideators (p = 0.009) and HC (p = 0.004). Recent suicide attempt, one of the most powerful predictors of suicide risk, was also most closely tied to inflammatory indices in this study. Low DHA% as an indicator of suicide risk is consistent with previous reports; however, lower IL-1β was unexpected and may relate to acuity/chronicity of inflammation. There is a need for prospective studies of immune status with respect to suicidal behaviors.

Polyunsaturated fatty acids as predictors of future suicide attempt

Polyunsaturated fatty acids (PUFAs) and cholesterol are lipids implicated in suicide risk. We prospectively studied plasma glycerophospholipid PUFAs and cholesterol as putative predictors of suicide attempts. In a multicenter cohort study, we enrolled 123 patients admitted to the emergency department (ED) for suicidal ideation or suicide attempt. Clinical assessments were performed, with follow-up telephone evaluations 6, 12, 18, and 24 months later. Blood samples were obtained in the ED and assayed for PUFAs. Using survival analysis, suicide events were not predicted by eicosapentaenoic acid (EPA, HR: -0.83, 95%CI: 0.39-1.76, p = 0.621) or docosahexaenoic acid (DHA, HR: -0.60, 95%CI: 0.19-1.86, p = 0.371). However, higher arachidonic acid (AA) was a trend for a protective factor (HR=0.30, 95%CI: 0.08-1.08, p = 0.065) in the entire trans-diagnostic sample. This protective effect was significant in all participants with a prior suicide attempt history (n = 85; HR=0.16, 95%CI: 0.04-0.67, p = 0.012), and in the subgroup of attempters with major depressive disorder (MDD; n = 55, HR=0.15, 95%CI:0.03-0.76, p = 0.002). Total LDL- and HDL-cholesterol did not predict subsequent suicide events. AA, but not DHA or EPA, positively correlated with baseline depression severity in MDD patients (r = 0.3, p = 0.006). Contrary to our hypothesis that low n-3 PUFA levels would create risk, we found that while higher AA was associated with greater depression severity at baseline, low AA unexpectedly predicted subsequent suicide attempts, the more so in higher-risk patients. Although surprising, this result agrees with a minority of reports concerning n-6 PUFAs and may represent complex interactions with sample characteristics.

Are Lipids Possible Markers of Suicide Behaviors?

Suicides and suicidal behaviors are very important causes of mortality and morbidity and have become a serious global problem. More than 800,000 people die from suicide every year. Previous researches have established that lipids play an important role in the pathogenesis of suicide. Moreover, lipid levels might be a biological marker of suicide. A lot of researchers have tried to identify biological markers that might be related to depressive disorder, bipolar disorder or schizophrenia and suicidal behavior. It was also important to consider the usefulness of an additional tool for prevention actions. Metabolic deregulation, particularly low total cholesterol and low-density lipoproteins-cholesterol levels may cause higher suicide risk in patients with these psychiatric disorders.

Prevalence and correlates of suicidal behaviour among a national population-based sample of adults in Zambia

Background

Suicide is a major public health issue.

Aim

This study aimed to assess the prevalence and correlates of lifetime suicide attempts and past 12-month suicidal behaviour (ideation, plans and/or attempts) among adults (18–69 years).

Setting

Zambia.

Method

National cross-sectional data from 4302 adults (median age: 31 years) who took part in the ‘2017 Zambia STEPS survey’ were analysed.

Results

The results indicate that 2.3% of participants had ever attempted suicide and 8.5% engaged in past 12-month suicidal behaviour (ideation 7.8%, plan 3.6% and/or attempt 1.1%). In adjusted logistic regression analysis, having a family member who died from suicide, having had a heart attack, angina or stroke and daily tobacco smoking were associated with ever suicide attempt. In adjusted logistic regression, female sex, non-paid work status (including student, homeworker and retired), alcohol use-related family problem, passive smoking, heart attack, angina or stroke and alcohol dependence were positively associated with past 12-month suicidal behaviour, and belonging to other ethnic groups was negatively associated with past 12-month suicidal behaviour. In addition, in an unadjusted analysis, 18–24-year-old participants, those who were never married, separated, divorced or widowed, having urban residence, family members died from suicide, having lower systolic blood pressure and daily smokeless tobacco use, were associated with past 12-month suicidal behaviour.

Conclusion

Almost 1 in 10 participants was engaged in suicidal behaviour in the past 12 months, and several associated indicators were found that can assist in planning interventions.

Serum β-endorphin levels are associated with addiction to suicidal behavior: A pilot study

The literature provides partial support for the hypothesis that some suicide attempters develop a behavioral addiction to suicidal behavior (SB). We hypothesized that major suicide repeaters (MR) (≥5 lifetime suicide attempts) are addicted to suicide attempts as measured by modified DSM-IV criteria for substance dependence. In this cross-sectional study with 13 psychiatric controls (PC), 55 non-major suicide attempters (NMR), and 9 MR we found that MR are characterized by emotional abuse and neglect, as well as higher scores on the Personality and Life Event scale (short version). The levels of 8 AM serum ACTH, cortisol and β-endorphin were elevated in all three groups. Serum β-endorphin (pg/mL) was particularly high in PC diagnosed with schizophrenia 220.34 (±56.30). The level of 8 AM serum β-endorphin rose with increased numbers of criteria met for addiction to SB from 130.31 (±88.16) (≥ 3 criteria met for addiction to SB) to 174.84 (±114.93) (≥ 6 criteria met for addiction to SB) whereas serum ACTH and cortisol did not change. SB addicts (≥ 6 criteria) displayed higher serum β-endorphin concentrations than non-addicts (174.84 ± 114.93 vs. 116.93 ± 61.70, FET p = 0.09). The present study brings some support to the addictive hypothesis of SB. Our results delineate β-endorphin as a promising biomarker of SB addiction, and offer a good basis for future studies that test whether buprenorphine can be used to prevent repetitive suicide attempts, non-suicidal-self-injury (NSSI), and the development of an addiction to SB.

Serum nesfatin-1, ghrelin, and lipid levels in adolescents with first episode drug naïve unipolar depression

Background: Major depressive disorder (MDD) is a mental health and emotional disorder that affects children and adolescents worldwide. This study aimed to evaluate serum nesfatin-1, ghrelin, and lipid levels as biological markers of adolescent MDD and their relationship with the severity of depression-anxiety and suicide risk in MDD. Methods:This study included 37 drug naïve adolescents between the ages of 12 and 18 who were diagnosed with a first episode MDD according to the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL) and DSM-V diagnostic criteria. Thirty-three healthy adolescents between the ages of 12 and 18 were included as the control group. The Children's Depression Inventory (CDI), Screen for Child Anxiety Related Disorders (SCARED), and Suicide Probability Scale (SPS) were used to evaluate the subjects in the MDD and control groups. In the first stage, serum nesfatin-1, ghrelin, and lipid levels were compared between the adolescents diagnosed with MDD and the control group. Next, the correlations between these levels and the CDI, SCARED, and SPS scores were evaluated. Results: Nesfatin-1 levels were significantly lower in the MDD group than the control group (p < 0.001) A positive correlation was found between the nesfatin-1 levels and the SPS scores. Conclusions: This is the first study to evaluate nesfatin-1 levels in adolescent depression, suggesting that nesfatin-1, ghrelin, total cholesterol, and low-density lipoprotein cholesterol (LDL) levels can be used as biomarkers in child-adolescent MDD. However, it is evident that further studies with larger samples and post-treatment measurements are needed.

Effects of Omega 3 Fatty Acids on Main Dimensions of Psychopathology

The usefulness of polyunsaturated fatty acids on inflammatory, cardiovascular, and the nervous system was studied in the last decades, but the mechanisms underlying their benefic properties are still partially unknown. These agents seem to express their action on the membrane phospholipid composition and permeability and modulation of second messenger cascades. In psychiatry, the efficacy and tolerability of omega-3 fatty acids were investigated in several psychiatric disorders, including major depression, bipolar disorder, personality disorders, high-risk conditions to develop psychosis, attention-deficit hyperactivity disorder, and autism spectrum disorders. Initial findings in this field are promising, and some relevant questions need to be addressed. In particular, the effects of these agents on the main symptom dimensions have to be investigated in a trans-diagnostic perspective. The present systematic review is aimed to examine the available data on the efficacy of omega-3 fatty acids on domains of psychotic symptoms, affective symptoms, impulsivity, and aggressiveness, and harmful behaviors, and suicide risk.

Low cholesterol levels in children predict impulsivity in young adulthood

OBJECTIVE

Severe behavioural issues such as impulsive action and suicide have since long been associated with low levels of cholesterol. While it is known that cholesterol plays a role in neural development and hence low levels of serum lipids could have long-term effects on behaviour, no longitudinal studies showed the association of serum lipids levels with impulsivity. We aimed to examine the prognostic properties of serum lipid levels during childhood and adolescence on measures of impulsivity during early adulthood in a representative birth cohort sample.

METHODS

We have investigated whether serum lipid levels measured at 9, 15, 18 and 25 years of age have an association with impulsivity in 25 years old young adults. This analysis was based on data of the birth cohort representative samples of the Estonian Children Personality Behaviour and Health Study (original n = 1238). Impulsivity was self-reported with the Adaptive and Maladaptive Impulsivity Scale.

RESULTS

Total and low-density lipoprotein (LDL) cholesterol measured in boys aged 9, 15 and 18 years predicted disinhibition and thoughtlessness in 25-year-old young adults. High scores of disinhibition were associated with low total and LDL cholesterol levels in males but, while less consistently, with high total and LDL cholesterol levels in females. Cross-sectional analysis did not result in systematic outcomes.

CONCLUSIONS

Serum lipid levels could have an impact on the development of Maladaptive Impulsivity starting from an early age. This effect of cholesterol continues throughout adolescence into young adulthood.

Predictors of relapse in high lethality suicide attempters: a six-month prospective study

BACKGROUND

This study is aimed to investigate the association between clinical, metabolic, inflammatory and environmental (photoperiod defined as daily sunlight exposure) parameters and suicide re-attempts after the index suicide attempt. Possible predictors of suicide re-attempts were also explored.

METHODS

Overall, 432 subjects with suicide attempts, of which 79 relapsed within the following six months were included in this prospective study. We adopted the Joiner's definition of suicide lethality, as "the acquired ability to enact lethal self-injury". The Cox regression was used to test the association between the mentioned variables and Kaplan-Meier plots showed the trend of suicide re-attempts.

RESULTS

Among participants, 30.8% committed a high-lethality suicide attempt. Cox regression confirmed the association between lifetime suicide attempts and number of suicide attempts in the study time-frame and suicide-reattempts. The longer photoperiod (Spring/Summer) was associated with suicide re-attempts, particularly patients with admission in June/July for the index event. Total cholesterol (TC), low-density lipo-protein cholesterol and c-reactive protein serum levels were significantly associated with suicide re-attempts but Cox regression confirmed only the association between lower TC serum levels and suicide re-attempt.

LIMITATIONS

Patients' seasonal environment, psychological factors, presence of acute life-events fostering the suicidal crisis and detailed medical history have been not investigated. Findings were derived from a single psychiatric unit.

CONCLUSIONS

Lifetime suicide attempts, higher number of previous suicide attempts, lower total cholesterol levels, and suicide attempt during longer photoperiod were significant predictors of suicide re-attempts. Further studies are needed in order to better characterize single- vs. multiple suicide attempter's profiles.

MicroRNA expression profiling of lymphoblasts from bipolar disorder patients who died by suicide, pathway analysis and integration with postmortem brain findings

Post-mortem brain studies suggest that miRNAs may be involved in suicide, but their role as peripheral biomarkers or targets of preventive pharmacological treatments in suicide has yet to be elucidated. We used nCounter miRNA Expression assay to measure miRNAs expression in lymphoblastoid cell lines (LCLs) from patients with Bipolar Disorder (BD) who died by suicide (SC, n = 7) and with low risk of suicide (LR, n = 11). Five miRNAs were differentially expressed in SC compared to LR (false discovery rate p<0.05). The two most significant miRNAs were measured with RT-qPCR in the same sample and in 12 healthy controls (HC): miR-4286 was increased while miR-186-5p was decreased in SC compared to LR and HC (ANOVA F = 14.92, p = 0.000043 and F = 3.95, p = 0.032 respectively). miR-4286 was also decreased in postmortem brains from 12 patients with BD who died by suicide compared to 13 controls, even though it did not reach statistical significance (FC=0.51, p = 0.07). Treatment with lithium of human neural progenitor cells reduced the expression of miR-4286 (FC=0.30, p = 0.038). Pathway analysis on predicted miR-4286 targets showed that "insulin resistance" was significantly enriched after correction for multiple testing. This pathway comprised 17 genes involved in lipid and glucose metabolism, several of which were also dysregulated in postmortem brains from patients with BD who died by suicide from the Stanley-foundation array collection. In conclusion, our study suggests that miR-4286 could be a biomarker of suicide but further studies are warranted to investigate its targeted genes and how these could be involved in the neurobiology of suicide.

Biomarkers of suicidal behaviors: A comprehensive critical review

Suicide is a relevant worldwide public health problem. Many studies have shown that different demographic and clinical factors are potentially associated with suicidal behavior. Other studies have reported data about the role of biomarkers in the onset of suicidal behaviors. Specifically, researchers have found that suicidal risk may be increased by abnormalities in serotonergic system, hypothalamic-pituitary-adrenal axis, lipid metabolism, immune system and neuronal plasticity. The identification of specific biological parameters associated with self-harm may be helpful to implement prevention strategies and also to detect new therapeutic strategies. In this review, we summarize and analyze the results of main studies about neurobiological mechanisms related to suicidal behavior, also exploring the possible interconnection between the different biological systems.

Seasonality Patterns of Internet Searches on Mental Health: Exploratory Infodemiology Study

BACKGROUND

The study of seasonal patterns of public interest in psychiatric disorders has important theoretical and practical implications for service planning and delivery. The recent explosion of internet searches suggests that mining search databases yields unique information on public interest in mental health disorders, which is a significantly more affordable approach than population health studies.

OBJECTIVE

This study aimed to investigate seasonal patterns of internet mental health queries in Ontario, Canada.

METHODS

Weekly data on health queries in Ontario from Google Trends were downloaded for a 5-year period (2012-2017) for the terms "schizophrenia," "autism," "bipolar," "depression," "anxiety," "OCD" (obsessive-compulsive disorder), and "suicide." Control terms were overall search results for the terms "health" and "how." Time-series analyses using a continuous wavelet transform were performed to isolate seasonal components in the search volume for each term.

RESULTS

All mental health queries showed significant seasonal patterns with peak periodicity occurring over the winter months and troughs occurring during summer, except for "suicide." The comparison term "health" also exhibited seasonal periodicity, while the term "how" did not, indicating that general information seeking may not follow a seasonal trend in the way that mental health information seeking does.

CONCLUSIONS

Seasonal patterns of internet search volume in a wide range of mental health terms were observed, with the exception of "suicide." Our study demonstrates that monitoring internet search trends is an affordable, instantaneous, and naturalistic method to sample public interest in large populations and inform health policy planners.

The role of seasonality and photoperiod on the lethality of suicide attempts: A case-control study

BACKGROUND

The risk factors related to suicidal behaviors are complex and not yet fully known. Several studies underline how suicide results from the combination of psycho-social, biological, cultural, and environmental factors. The aim of this study was to investigate the potential role of seasonality and photoperiod on high-lethality suicide attempts (HLSA) compared with low-lethality suicide attempts (LLSA) in a sample of psychiatric inpatients.

METHODS

After attempting suicide, subjects were admitted in the emergency/psychiatric ward of the IRCCS Ospedale Policlinico San Martino from 1st August 2013 to 31st July 2018. Socio-demographic and clinical characteristics were collected.

RESULTS

The sample consisted of four hundred thirty-two individuals admitted for suicide attempt. One hundred thirty-three subjects (30.8%) of the sample committed a HLSA. The HLSA group peaked in the months with a higher sunlight exposure (June and July). Bivariate correlation analyses between seasonality/photoperiod in the whole sample and HLSA were positively associated with summer and highest solar intensity period.

LIMITATIONS

Data were limited to a single hospital, patients' seasonal environment, meteorological variables and psychological factors. In addition, the presence of acute life-events fostering the suicidal crisis has not been investigated.

CONCLUSIONS

The current study provides a novel perspective on the questions surrounding the impact of seasonality and daylight exposure on lethality of suicide attempts. further studies are needed to provide deeper understandings on the delicate molecular network that links suicide behaviors, seasonality and daylight in order to develop more effective prevention and treatment strategies in the future.

The Association Between Dyslipidemia and Lethality of Suicide Attempts: A Case-Control Study

Evidence supports the existence of an association between dyslipidemia, psychiatric disorders, and suicide risk due to the effects of altered lipid profiles on serotoninergic neuron membranes. The aim of this study was to investigate the differences in c-reactive protein (CRP), thyroid functioning, total cholesterol, high lipoprotein density cholesterol (HDL-c), low-lipoprotein density cholesterol (LDL-c), and triglycerides (TG) serum levels in low lethality (LLSA) vs. high lethality suicide attempters (HLSA) within 24 h from the suicide attempt and inpatients who never attempted suicide (NAS). After attempting suicide, subjects were admitted to the emergency ward of the IRCCS Ospedale Policlinico San Martino and later to the section of Psychiatry from 1st August 2013 to 31st July 2018. Socio-demographic and clinical characteristics, serum lipids profile, CRP, and thyroid functioning were collected. The sample consisted of 133 individuals with a HLSA, 299 subjects with LLSA, and 200 patients NAS. HLSA subjects were more likely to be males and diagnosed as having a bipolar disorder. Furthermore, HLSA subgroup showed significantly lower total cholesterol and LDL-c levels and higher CRP serum levels compared to LLSA and control group, respectively. LLSA subgroup showed higher HDL-c levels compared to HLSA subgroup (no differences between HLSA and control group were observed). Additionally, the control group reported higher triglycerides levels compared to patients admitted to psychiatric ward for a suicide attempt. Only male gender, having a diagnosis of bipolar disorder, lower total cholesterol, and higher CRP serum levels predicted HLSA. Investigating the relation between dyslipidemia and the severity of suicide attempts may contribute to reveal the complex determinants underlying at-risk behaviors such as suicide, thus playing a relevant role in the possible prevention of this disabling phenomenon.

Advances and challenges in understanding the role of the lipid raft proteome in human health

INTRODUCTION

Phase separation as a biophysical principle drives the formation of liquid-ordered 'lipid raft' membrane microdomains in cellular membranes, including organelles. Given the critical role of cellular membranes in both compartmentalization and signaling, clarifying the roles of membrane microdomains and their mutual regulation of/by membrane proteins is important in understanding the fundamentals of biology, and has implications for health. Areas covered: This article will consider the evidence for lateral membrane phase separation in model membranes and organellar membranes, critically evaluate the current methods for lipid raft proteomics and discuss the biomedical implications of lipid rafts. Expert commentary: Lipid raft homeostasis is perturbed in numerous chronic conditions; hence, understanding the precise roles and regulation of the lipid raft proteome is important for health and medicine. The current technical challenges in performing lipid raft proteomics can be overcome through well-controlled experimental design and careful interpretation. Together with technical developments in mass spectrometry and microscopy, our understanding of lipid raft biology and function will improve through recognition of the similarity between organelle and plasma membrane lipid rafts and considered integration of published lipid raft proteomics data.