Low serum cholesterol in suicide attempters

Serum Lipid Levels and Suicidal Ideation of Adults: A Cross-Sectional Study Using the Korea National Health and Nutrition Examination Survey

Cholesterol plays a crucial role in the brain, which suggests that changes in its concentration levels may have an impact on the central nervous system. To examine the association between serum lipid levels and suicidal ideation according to sex, we performed a cross-sectional study using data from the Korea National Health and Nutrition Examination Survey 2014-2018. A total of 13,772 adults 19 years or older were analyzed. The ninth item of the Patient Health Questionnaire was used to evaluate the suicidal ideation of participants. After sorting by sex, a complex logistic regression was performed to measure the association between serum lipid indicators and suicidal ideation. The analysis adjusted for age, body mass index, smoking, heavy drinking, regular exercise, household income, education level, dyslipidemia medication, depression, and chronic diseases. Compared to the intermediated category, the lowest range of low-density lipoprotein cholesterol (LDL-C; <100 mg/dL) was associated with increased suicidal ideation in men (odds ratio [OR] = 1.97; 95% confidence interval [CI]: 1.30-3.01). The association between lipid levels and suicidal ideation was not clear in women. We found an association between lower LDL-C levels and an increased risk of suicidal ideation among Korean men aged 19 years or older.

How do lipids influence risk of violence, self-harm and suicidality in people with psychosis? A systematic review

OBJECTIVES

Low cholesterol has been linked with violent and suicidal behaviour in people with schizophrenia. This association, if consistently present, may be a promising biological marker that could assist clinicians in decision making regarding risk and treatment. We conducted a systematic review to assess whether there is a reliable association between lipid profile (total cholesterol, high- and low-density lipoprotein cholesterol, and triglycerides) and aggression, self-harm or suicide in people with schizophrenia, and whether effects are similar in males and females.

METHOD

Relevant databases were searched to identify primary research studies (up to November 2020) that (1) involved adults (some samples also included 16- to 18-year olds) with a confirmed diagnosis of schizophrenia, schizoaffective disorder or psychosis; and (2) included a standardised assessment of verbal aggression, physical aggression against objects, physical aggression against self (including suicide) or others. The search yielded 23 studies eligible for inclusion following a quality appraisal.

RESULTS

Suicidality was the most commonly assessed subtype of aggression (20 studies). For suicidality, about half the studies, including the study with the largest sample size, found a link with total cholesterol. An association between low total cholesterol and violence towards others was found in six of nine studies that investigated this. The evidence for a link with violence was the strongest for total cholesterol, followed by low-density lipoprotein cholesterol and high-density lipoprotein cholesterol, and the weakest for triglycerides. Only a few studies investigated sex differences and yielded mixed evidence. Studies focussed on self-harm as well as involving females in forensic settings were lacking.

CONCLUSION

There is encouraging evidence of an association between low total cholesterol and aggression towards others as well as suicidality in schizophrenia. Future studies should systematically explore this association in people with schizophrenia who have a significant history of violence, suicidality and self-harm, both inpatients and community, and also investigate underlying mechanisms.

The Relationships between Abnormal Serum Lipid Levels, Depression, and Suicidal Ideation According to Sex

(1) Background: Serum lipid levels affect not only nutritional status but also emotional state. The purpose of this study was to examine the effects of various socio-demographic characteristics, abnormal cholesterol levels, and BMI indicators on depressive symptoms and suicidal ideation in the Korean population. (2) Methods: A total of 23,692 people were surveyed using data from the Korea National Health and Nutrition Examination Survey (KNHNES) 2014, 2016, and 2018. Data from 11,653 patients were analyzed. Age, sex, chronic disease, smoking, alcohol consumption, total cholesterol (HDL, triglycerides), BMI, depression, and suicidal ideation were measured. (3) Results: According to sex, low HDL, high triglycerides, and suicidal ideation were significant, along with low education level, smoking, binge drinking, and high BMI. High triglyceride level was shown to significantly increase the risk of depression in males (OR = 1.535, 95% CI = 1.098-2.147). Factors affecting suicidal ideation in males were age, binge drinking, and depression, while blood lipid factors were not significant. (4) Conclusions: Of the types of serum lipid factors affecting depression and suicidal ideation, high triglycerides were found to be a risk factor for depression in men. Serum lipids can be used as biomarkers to reflect depressive symptoms in men depending on cholesterol level.

Neurobiological Basis of Increased Risk for Suicidal Behaviour

According to the World Health Organization (WHO), more than 700,000 people die per year due to suicide. Suicide risk factors include a previous suicide attempt and psychiatric disorders. The highest mortality rate in suicide worldwide is due to depression. Current evidence suggests that suicide etiopathogenesis is associated with neuroinflammation that activates the kynurenine pathway and causes subsequent serotonin depletion and stimulation of glutamate neurotransmission. These changes are accompanied by decreased BDNF (brain-derived neurotrophic factor) levels in the brain, which is often linked to impaired neuroplasticity and cognitive deficits. Most suicidal patients have a hyperactive hypothalamus–pituitary–adrenal (HPA) axis. Epigenetic mechanisms control the above-mentioned neurobiological changes associated with suicidal behaviour. Suicide risk could be attenuated by appropriate psychological treatment, electroconvulsive treatment, and drugs: lithium, ketamine, esketamine, clozapine. In this review, we present the etiopathogenesis of suicide behaviour and explore the mechanisms of action of anti-suicidal treatments, pinpointing similarities among them.

Serum lipids and suicidal risk among patients with schizophrenia spectrum disorders: Systematic review and meta-analysis

OBJECTIVE

A systematic review of literature was conducted to determine the association between serum lipids and suicidality in people with schizophrenia spectrum disorders.

METHODS

We undertook a systematic search of multiple databases for studies that ascertained an association between serum lipids and suicidality in adult patients with schizophrenia spectrum disorders (18-65 years) from database inception to 2 September 2020. Qualitative analysis was done using National Institute of Health (NIH) scales. The standard mean difference (SMD) and 95% confidence intervals (CI) were calculated for each study and standardized relative to the study. Adjusted p-value, Z-test, and heterogeneity were calculated, as well as testing for publication bias.

RESULTS

Of 1262 records identified, 17 studies (n = 3113) were included in our systematic review, while 11 studies were included in the meta-analysis. The majority of studies (11) rated fair on qualitative analysis. Data from seven studies (n = 1597) revealed a medium effect size for an association between low total cholesterol and suicide attempts (SMD -0.560; 95% CI: 0.949-0.170; p = 0.005). People with history of suicide attempt had a mean cholesterol value 0.56 SD lower than the mean in those without suicide attempts. There were differences in how a suicide attempt was defined and there was high heterogeneity (I² = 83.3%). No significant association was found between any of the serum lipid parameters and suicide ideation. Funnel-plot analysis suggested small study effects with publication bias.

CONCLUSIONS

Suicide attempts in people with schizophrenia spectrum disorders are associated with low mean total cholesterol levels.

Understanding the Complex of Suicide in Depression: from Research to Clinics

OBJECTIVE

Amongst psychiatric disorders, major depressive disorder (MDD) is the most prevalent, by affecting approximately 15-17% of the population and showing a high suicide risk rate equivalent to around 15%. The present comprehensive overview aims at evaluating main research studies in the field of MDD at suicide risk, by proposing as well as a schematic suicide risk stratification and useful flow-chart for planning suicide preventive and therapeutic interventions for clinicians.

METHODS

A broad and comprehensive overview has been here conducted by using PubMed/Medline, combining the search strategy of free text terms and exploded MESH headings for the topics of 'Major Depressive Disorder' and 'Suicide' as following: ((suicide [Title/Abstract]) AND (major depressive disorder [Title/Abstract])). All articles published in English through May 31, 2019 were summarized in a comprehensive way.

RESULTS

Despite possible pathophysiological factors which may explain the complexity of suicide in MDD, scientific evidence supposed the synergic role of genetics, exogenous and endogenous stressors (i.e., interpersonal, professional, financial, as well as psychiatric disorders), epigenetic, the hypothalamic-pituitary-adrenal stress-response system, the involvement of the monoaminergic neurotransmitter systems, particularly the serotonergic ones, the lipid profile, neuro-immunological biomarkers, the Brain-derived neurotrophic factor and other neuromodulators.

CONCLUSION

The present overview reported that suicide is a highly complex and multifaceted phenomenon in which a large plethora of mechanisms could be variable implicated, particularly amongst MDD subjects. Beyond these consideration, modern psychiatry needs a better interpretation of suicide risk with a more careful assessment of suicide risk stratification and planning of clinical and treatment interventions.

Drugs used in the treatment of bipolar disorder and their effects on cholesterol biosynthesis - A possible therapeutic mechanism

Objectives: To understand the therapeutic mechanisms of bipolar disorder (BD) drugs at molecular and cellular levels.Methods: Next generation sequencing was used to determine the transcriptional effects of a combination of four commonly prescribed BD drugs (lithium, valproate, lamotrigine and quetiapine) or vehicle (0.2% DMSO) in NT2-N (human neuronal) cells and rats. Differential expression of genes and pathway analysis were performed using edgeR in R and Gene Set Enrichment Analysis software respectively. Free cholesterol levels and neurite outgrowth were quantified in NT2-N cells following combination and individual BD drug treatments.Results: Pathway analysis showed up-regulation of many elements of the cholesterol biosynthesis pathway in NT2-N cells and oxidative phosphorylation in rat brains. Intracellular cholesterol transport genes were upregulated (NPC1, NPC2 and APOE), while the cholesterol efflux gene (ABCA1) was downregulated. BD drug combination tended to increase intracellular cholesterol levels and neurite outgrowth, but these effects were not seen for the drugs when used individually.Conclusions: These data suggest that BD drug combination is increasing cholesterol biosynthesis and the newly synthesised cholesterol is being utilised within the cells, possibly for synthesis of new membranes to facilitate neurite outgrowth. This mechanism possibly underpins clinical efficacy in individuals with BD treated with polypharmacy.

Comparison of blood lipid profile/thyroid function markers between unipolar and bipolar depressed patients and in depressed patients with anhedonia or suicidal thoughts

Background

This study aimed to investigate the differences in the serum levels of glucose, lipid, and thyroid function markers between unipolar and bipolar depressed patients, as well as the effect of anhedonia and suicidal thoughts on the levels of these biochemical parameters.

Methods

A total of 287 unmedicated depressed patients from January 2016 to December 2017 were included in this study, including 92 bipolar depressions and 195 unipolar depressions. Anhedonia was determined using the item 32 of Symptom Checklist (SCL-90). Suicide ideation was assessed by item 15 of SCL-90.

Results

The bipolar group had significantly lower lipid levels (including triglycerides, cholesterol, low-density lipoprotein cholesterol [LDL], very low-density lipoprotein cholesterol [VLDL]) and insulin resistance index but higher levels of prolactin, low triiodothyronine (T3) and free T3 (FT3) as well as higher incidence of anhedonia as compared with the unipolar group. Depressed patients with anhedonia had significantly higher LDL level than those without anhedonia. Depressed patients with suicidal thoughts had cholesterol and high-density lipoprotein cholesterol (HDL) level. The above-mentioned differences were confirmed by logistic regression analysis. Receiver operating characteristic curve (ROC) analysis showed that the area under the ROC curve (AUC) ranged from 0.546 to 0.685.

Conclusion

Triglycerides, cholesterol, LDL, VLDL T3, FT3 levels were significantly different between unipolar and bipolar depressed patients, which might have the potential to be the markers for differential diagnosis. Patients with anhedonia had lower LDL level, while patients with suicidal thoughts had higher levels of cholesterol and HDL as compared with the corresponding control groups.

Deficiency or activation of peroxisome proliferator-activated receptor α reduces the tissue concentrations of endogenously synthesized docosahexaenoic acid in C57BL/6J mice

BACKGROUND/OBJECTIVES

Docosahexaenoic acid (DHA), an n-3 long chain polyunsaturated fatty acid (LCPUFA), is acquired by dietary intake or the in vivo conversion of α-linolenic acid. Many enzymes participating in LCPUFA synthesis are regulated by peroxisome proliferator-activated receptor alpha (PPARα). Therefore, it was hypothesized that the tissue accretion of endogenously synthesized DHA could be modified by PPARα.

MATERIALS/METHODS

The tissue DHA concentrations and mRNA levels of genes participating in DHA biosynthesis were compared among PPARα homozygous (KO), heterozygous (HZ), and wild type (WT) mice (Exp I), and between WT mice treated with clofibrate (PPARα agonist) or those not treated (Exp II). In ExpII, the expression levels of the proteins associated with DHA function in the brain cortex and retina were also measured. An n3-PUFA depleted/replenished regimen was applied to mitigate the confounding effects of maternal DHA.

RESULTS

PPARα ablation reduced the hepatic Acox, Fads1, and Fads2 mRNA levels, as well as the DHA concentration in the liver, but not in the brain cortex. In contrast, PPARα activation increased hepatic Acox, Fads1, Fads2 and Elovl5 mRNA levels, but reduced the DHA concentrations in the liver, retina, and phospholipid of brain cortex, and decreased mRNA and protein levels of the brain-derived neurotrophic factor in brain cortex.

CONCLUSIONS

LCPUFA enzyme expression was altered by PPARα. Either PPARα deficiency or activation-decreased tissue DHA concentration is a stimulus for further studies to determine the functional significance.

Disentangling the genetic overlap between cholesterol and suicide risk

Suicide is major public health concern; one million individuals worldwide die by suicide each year of which there are many more attempts. Thus, it is imperative that robust and reliable indicators, or biomarkers, of suicide risk be identified so that individuals at risk can be identified and provided appropriate interventions as quickly as possible. Previous work has revealed a relationship between low levels of circulating cholesterol and suicide risk, implicating cholesterol level as one such potential biomarker, but the factors underlying this relationship remain unknown. In the present study, we applied a combination of bivariate polygenic and coefficient-of-relatedness analysis, followed by mediation analysis, in a large sample of Mexican-American individuals from extended pedigrees [N = 1897; 96 pedigrees (average size = 19.17 individuals, range = 2-189) 60% female; mean age = 42.58 years, range = 18-97 years, sd = 15.75 years] with no exclusion criteria for any given psychiatric disorder. We observed that total esterified cholesterol measured at the time of psychiatric assessment shared a significant genetic overlap with risk for suicide attempt (ρ_g = -0.64, p = 1.24 × 10^-04). We also found that total unesterified cholesterol measured around 20 years prior to assessment varied as a function of genetic proximity to an affected individual (h² = 0.21, se = 0.10, p = 8.73 × 10^-04; β_suicide = -0.70, se = 0.25, p = 8.90 × 10^-03). Finally, we found that the relationship between total unesterified cholesterol and suicide risk was significantly mediated by ABCA-1-specific cholesterol efflux capacity (β_{suicide-efflux} = -0.45, p = 0.039; β_{efflux-cholexterol} = -0.34, p < 0.0001; β_indirect = -0.15, p = 0.044). These findings suggest that the relatively well-delineated process of cholesterol metabolism and associated molecular pathways will be informative for understanding the neurobiological underpinnings of risk for suicide attempt.

Elevated allostatic load in individuals presenting at psychiatric emergency services

OBJECTIVE

Individuals requiring psychiatric emergency services are often highly distressed and intoxicated. To provide an objective and comprehensive measure of their stress-related physiological dysregulations, we indexed allostatic load with 14 biomarkers collected within 24 h of patients' admission to the largest psychiatric hospital in the Canadian province of Quebec.

METHODS

This study (N = 278) combines data for emergency patients (n = 76; 65.8% women; M age = 44.97, SE = 1.6) and hospital workers who served as sex- and age-matched controls (n = 202; 70.8% women; M age = 40.10, SE = 0.83). Sex-specific allostatic load indices summarized neuroendocrine (cortisol), immune (tumor necrosis factor-α, interleukin-6, c-reactive protein), metabolic (insulin, glycosylated hemoglobin, total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, body mass index), and cardiovascular (heart rate, systolic and diastolic blood pressure) functioning. Well-validated questionnaires assessed substance (ab)use.

RESULTS

Individuals presenting at psychiatric emergency showed elevated allostatic load, drug abuse, and tobacco use compared to controls. Elevated allostatic load in emergency patients was driven by elevated cortisol, interleukin-6, systolic blood pressure, and heart rate; however, allostatic load was not explained by substance (ab)use or demographic variables. Sub-group analyses revealed that emergency patients primarily diagnosed with bipolar, depressive, or anxiety disorders showed higher allostatic load than those diagnosed with personality disorder(s).

CONCLUSIONS

This study demonstrates that individuals presenting at psychiatric emergency services show physiological dysregulations associated with chronic stress. Future research should explore the clinical utility of allostatic load in predicting comorbidities among psychiatric patients.

Areca nut chewing is associated with common mental disorders: a population-based study

INTRODUCTION

Forms of habitual substance use including cigarette smoking and alcohol consumption have been documented as risk factors of common mental disorders (CMDs). The effects of areca nut chewing on biophysiological tests, metabolic syndromes, and liver function have been reported previously; however, the relationship between areca nut chewing and CMDs remains unclear. This study examined the association between areca nut chewing and CMDs and explored the relationships between areca nut chewing and biophysiological indicators.

METHODS

A total of 4477 community dwellers who had enrolled in a cohort study and participated in health examinations in 2 consecutive years were selected for analysis in the present study. The community cohort was established in northern Taiwan during 2006-2012. The Chinese health questionnaire (CHQ-12) was used as a self-reported screening instrument to assess the potential for developing psychotic mental disorders (CHQ-12 score ≥ 3) among the community residents. Biophysiological tests performed 1 year before CMD assessment were analyzed to examine the causal pathways between areca nut chewing and CMDs. Multiple logistic regression and stratified analyses were performed.

RESULTS

A total of 18.23% of the participants were diagnosed as having CMDs. Factors including areca nut chewing [odds ratio (OR) 1.828; 95% confidence interval (CI) 1.165-2.869], sex (women; OR 1.828; 95% CI 1.165-2.869), age (30-49; OR 1.302; 95% CI 1.073-1.579), and socioeconomic status (lower status; OR 1.373; 95% CI 1.084-1.738) were associated with CMDs in a multiple logistic regression model. Areca nut chewers exhibited significantly more triglycerides (220.04 vs. 124.16 mg/dL) and white blood cells (65.17 102/μL vs. 60.36 102/μL) and significantly higher diastolic blood pressure (78.83 vs. 75.84 mmHg) and glutamic oxaloacetic transaminase (30.30 vs. 25.45 U/L) than did the controls.

CONCLUSIONS

This study demonstrated the association between areca nut chewing and CMDs and its effects on biophysiological tests in a community-based population in Taiwan. The findings suggest the existence of mechanistic effects of areca nut chewing on CMDs exerted through multiple pathways that may interact with pre-existing biophysiological abnormalities. Lifestyle variables should be considered for the prevention and management of mental disorders in the future.

Research on potential biomarker correlates for suicidal behavior: A review

Suicide is a world health priority. Studies over the last few decades have revealed the complexity underlying the neurobiological mechanisms of suicide. Researchers have found dysregulations in the serotonergic system, the stress system, neural plasticity, lipid metabolism, and cell signaling pathways in relation to suicidal behaviors. These findings have provided more insight into the final path leading to suicide, at which medical intervention should be applied to prevent the action. However, because these molecular mechanisms have been implicated in both depression and suicide, the specificity of the mechanisms has been obscured. In this review, we summarize the main findings of studies on molecular mechanisms of suicidal behavior from the last 2 decades, with particular emphasis on the potential, independent role of each mechanism that is not contingent upon an underlying psychopathology, such as depression. The act of suicide is multifactorial; no single molecular mechanism is sufficient to fully account for the act. Knowledge of the reciprocal interactions among these molecular mechanisms and studying them in the context of brain circuitry by using neuroimaging techniques will provide a better understanding of the neurobiology of suicide.

The Role of Lipid Biomarkers in Major Depression

In the UK, the lifetime-documented prevalence of major depressive disorder (MDD) is currently 10%. Despite its increasing prevalence and devastating impact on quality of life, the pathophysiological mechanisms underpinning MDD remain to be fully elucidated. Current theories of neurobiological components remain incomplete and protein-centric, rendering pharmacological treatment options suboptimal. In this review, we highlight the pivotal role of lipids in intra- and inter-neuronal functioning, emphasising the potential use of lipids as biomarkers for MDD. The latter has significant implications for improving our understanding of MDD at the cellular and circuit level. There is particular focus on cholesterol (high and low density lipoprotein), omega-3, and omega-6 polyunsaturated fatty acids due to established evidence in the literature of a link between atherosclerotic disease and major depression. We argue that there is significant potential scope for the use of such peripheral biomarkers in the diagnosis, stratification and treatment of MDD.

The Role of Nutrients in Protecting Mitochondrial Function and Neurotransmitter Signaling: Implications for the Treatment of Depression, PTSD, and Suicidal Behaviors

Numerous studies have linked severe stress to the development of major depressive disorder (MDD) and suicidal behaviors. Furthermore, recent preclinical studies from our laboratory and others have demonstrated that in rodents, chronic stress and the stress hormone cortisol cause oxidative damage to mitochondrial function and membrane lipids in the brain. Mitochondria play a key role in synaptic neurotransmitter signaling by providing adenosine triphosphate (ATP), mediating lipid and protein synthesis, buffering intracellular calcium, and regulating apoptotic and resilience pathways. Membrane lipids are similarly essential to central nervous system (CNS) function because cholesterol, polyunsaturated fatty acids, and sphingolipids form a lipid raft region, a special lipid region on the membrane that mediates neurotransmitter signaling through G-protein-coupled receptors and ion channels. Low serum cholesterol levels, low antioxidant capacity, and abnormal early morning cortisol levels are biomarkers consistently associated with both depression and suicidal behaviors. In this review, we summarize the manner in which nutrients can protect against oxidative damage to mitochondria and lipids in the neuronal circuits associated with cognitive and affective behaviors. These nutrients include ω3 fatty acids, antioxidants (vitamin C and zinc), members of the vitamin B family (Vitamin B12 and folic acid), and magnesium. Accumulating data have shown that these nutrients can enhance neurocognitive function, and may have therapeutic benefits for depression and suicidal behaviors. A growing body of studies suggests the intriguing possibility that regular consumption of these nutrients may help prevent the onset of mood disorders and suicidal behaviors in vulnerable individuals, or significantly augment the therapeutic effect of available antidepressants. These findings have important implications for the health of both military and civilian populations.

African Americans, Depression, and Suicide Risk

The aim of the current study was to determine which variable would be a better predictor of suicide risk: perceived social support or serum cholesterol level. There was a significant negative correlation between suicide risk and perceived social support but no significant correlation between suicide risk and serum cholesterol. Perceived social support was a better predictor of suicide risk than was serum cholesterol level and accounted for 17% of the variance. Depressed patients with a history of suicide attempt had a significantly lower serum cholesterol level, scored significantly higher on the Suicide Risk Scale, and scored significantly lower on the Perceived Social Support Scale than did depressed patients with no history of suicide attempt. Findings suggest that perceived social support is a better predictor of suicide risk for depressed African Americans.

A Retrospective Evaluation of the Inflammatory Marker C-Reactive Protein (CRP), Cholesterol and High-Density Lipoproteins in Patients with Major Depression: Preliminary Findings

The aim of this study was to retrospectively evaluate the role of C-reactive protein, total cholesterol and high-density lipoprotein cholesterol in patients suffering from Major Depression (MD). Data of C-reactive protein, total cholesterol (TC) and high-density lipoprotein cholesterol of 37 adult outpatients (17 men, 20 women) with a DSM-IV diagnosis of MD were analyzed. Depression was measured with the 17-item Hamilton Depression Rating Scale (HAM-D) and with the Beck Depression Inventory (BDI). Suicide risk was evaluated with the Scale of Suicide Ideation (SSI). Patients with a lifetime history of attempted suicide were categorized as having higher suicide risk. Higher suicide risk patients showed higher C-reactive protein levels and lower high-density lipoprotein cholesterol levels than lower suicide risk patients whereas total cholesterol levels were not statistically different. C-reactive protein positively correlated with BDI, HAM-D, SSI scores and with number of previous depressive episodes. High-density lipoprotein cholesterol correlated inversely with BDI, HAM-D and SSI scores, whereas, no significant correlations were found between Total Cholesterol and other variables including C-reactive protein. In linear regression models, C-reactive protein was predictor of more severe depression and increased suicide risk. Lower high-density lipoprotein cholesterol levels were significantly predictive of increased suicide risk.

Serum lipid levels and suicidality: a meta-analysis of 65 epidemiological studies

BACKGROUND

We conducted a systematic review and meta-analysis to determine the association between serum lipid levels and suicidality, as evidence from previous studies has been inconsistent.

METHODS

We identified relevant studies by searching Medline, Web of Science, EMBASE, and the Cochrane Database of Systematic Reviews (1980 to Dec. 5, 2014). Studies assessing the association between serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and/or triglycerides (TG) levels and suicidality were included. We used a random-effects model to take into account heterogeneity among studies.

RESULTS

We included 65 studies with a total of 510 392 participants in our analysis. Compared with the nonsuicidal patients, suicidal patients had significantly lower serum TC (weighted mean difference [WMD] -22.35, 95% confidence interval [CI] -27.95 to -16.75), LDL-C (WMD -19.56, 95% CI -26.13 to -12.99) and TG (WMD -23.40, 95% CI -32.38 to -14.42) levels, while compared with the healthy controls, suicidal patients had significantly lower TC (WMD -24.75, 95% CI -27.71 to -21.78), HDL-C (WMD -1.75, 95% CI -3.01 to -0.48) and LDL-C (WMD -3.85, 95% CI -7.45 to -0.26) levels. Furthermore, compared with the highest serum TC level category, a lower serum TC level was associated with a 112% (95% CI 40%-220%) higher risk of suicidality, including a 123% (95% CI 24%-302%) higher risk of suicide attempt and an 85% (95 CI 7%-221%) higher risk of suicide completion. The cut-off values for low and high serum TC level were in compliance with the categories reported in the original studies.

LIMITATIONS

A major limitation of our study is the potential heterogeneity in most of the analyses. In addition, the suicidal behaviour was examined using different scales or methods across studies, which may further explain heterogeneity among the studies.

CONCLUSION

We identified an inverse association between serum lipid levels and suicidality. More mechanistic studies are needed to further explain this association.

Higher total cholesterol level is associated with suicidal ideation in first-episode schizophrenia females

There are inconsistent reports showing that the relationship between total cholesterol (TC) level and suicidality might be gender-specific. We compared 30 first-episode schizophrenia (FES) patients reporting suicidal ideation based on the Operational Criteria for Psychotic Illness (OPCRIT) checklist with 70 FES patients, who have never experienced suicidal ideation. After controlling for potential confounders, higher TC was associated with suicidal ideation only in FES females. Future studies should disentangle biological underpinnings of this gender-specific association.

Potential neurochemical links between cholesterol and suicidal behavior

The role of cholesterol in psychiatric diseases has aroused the interest of the medical community, particularly in association with violent and suicidal behavior. Herein, we discuss some aspects of brain cholesterol metabolism, exploring possible mechanisms underlying the findings and reviewing the available literature on the possible neurochemical link between suicide and low or reduced levels of serum cholesterol. Most of the current hypotheses suggest a decreased serotonergic activity due to a decrease in cholesterol in the lipid rafts of synaptic membranes. Some aspects and limitations of this assumption are emphasized. In addition to serotonin hypofunction, other mechanisms have been proposed to explain increased impulsivity in suicidal individuals, including steroid modulation and brain-derived neurotrophic factor decrease, which could also be related to changes in lipid rafts. Other putative markers of suicidal behavior (e.g. protein S100B) are discussed in connection with cholesterol metabolism in the brain tissue.

Depressive symptoms in chronic hepatitis C are associated with plasma apolipoprotein E deficiency

Neuro-psychiatric and cognitive disorders are frequent in patients with chronic hepatitis C (CHC) virus (HCV) infection which adversely impact quality of life, antiviral treatment adherence and outcome. HCV has neurotrophic properties and affects lipid metabolism, essential for cognitive function. We evaluated the relationship of lipid profiles with depression and anxiety symptoms and the effects of 12-weeks of therapy with fluvastatin and omega-3 ethyl esters (n-3 PUFA) in a randomised pilot study of CHC prior non-responders. Participants (n = 60) had fasting lipid profiles and assessment of depression and anxiety symptoms using the Hospital Anxiety and Depression Scale (HADS) questionnaire at each study visit. At screening 26/60 (43 %) had HADS-A score ≥8 and 13/60 (22 %) had HADS-D scores ≥8. Depressed patients had significantly lower apolipoprotein-E concentrations (30 mg/l vs 39 mg/l, P = 0.029) than those without depression and a tendency toward lower total cholesterol (3.8 vs 4.4 mmol/l, P = 0.053). 3 patients discontinued lipid-modifying treatment because of worsening depression. However, there was a small but significant improvement in anxiety symptoms after 12-weeks of high-dose (2-4 g daily) n-3 PUFA. In conclusion, depression in CHC is associated with plasma apoE deficiency. We postulate that apoE deficiency disrupts blood brain barrier integrity to promote HCV infection of the CNS. High-dose n-PUFAs may alleviate anxiety in some CHC patients but the use of lipid lowering therapy must be balanced against risks of worsening depression.

Neuropsychiatric adverse events associated with statins: epidemiology, pathophysiology, prevention and management

Statins, or 3-hydroxy-3-methyl-glutaryl coenzyme A reductase inhibitors, such as lovastatin, atorvastatin, simvastatin, pravastatin, fluvastatin, rosuvastatin and pitavastatin, are cholesterol-lowering drugs used in clinical practice to prevent coronary heart disease. These drugs are generally well tolerated and have been rarely associated with severe adverse effects (e.g. rhabdomyolysis). Over the years, case series and data from national registries of spontaneous adverse drug reaction reports have demonstrated the occurrence of neuropsychiatric reactions associated with statin treatment. They include behavioural alterations (severe irritability, homicidal impulses, threats to others, road rage, depression and violence, paranoia, alienation, antisocial behaviour); cognitive and memory impairments; sleep disturbance (frequent awakenings, shorter sleep duration, early morning awakenings, nightmares, sleepwalking, night terrors); and sexual dysfunction (impotence and decreased libido). Studies designed to investigate specific neuropsychiatric endpoints have yielded conflicting results. Several mechanisms, mainly related to inhibition of cholesterol biosynthesis, have been proposed to explain the detrimental effects of statins on the central nervous system. Approaches to prevent and manage such adverse effects may include drug discontinuation and introduction of dietary restrictions; maintenance of statin treatment for some weeks with close patient monitoring; switching to a different statin; dose reduction; use of ω-3 fatty acids or coenzyme Q10 supplements; and treatment with psychotropic drugs. The available information suggests that neuropsychiatric effects associated with statins are rare events that likely occur in sensitive patients. Additional data are required, and further clinical studies are needed.

Triglycerides as a biological marker of repeated re-hospitalization resulting from deliberate self-harm in acute psychiatry patients: a prospective observational study

BACKGROUND

Biological factors have been associated with deliberate self-harm (DSH) but have not been integrated with clinical factors in routine risk assessments.This study aimed to examine the incremental validity of lipid levels and platelet serotonin when combined with psychosocial factors in risk assessments for repeated admissions due to DSH.

METHODS

In this prospective observational study of 196 acutely admitted patients, results of blood tests performed upon admission and the MINI Suicidal Scale and psychosocial DSH risk factor assessments performed at discharge were compared with the incidence of DSH recorded during the first 3 and 12 months after discharge.

RESULTS

High triglyceride levels were found to be a significant marker for patients admitted 3 or more times due to DSH (repeated DSH, DSH-R) when tested against other significant risk factors. When all (9) significant univariate factors associated with 12-month post-discharge DSH-R were analyzed in a multivariate logistic regression, the MINI Suicidal Scale (p = 0.043), a lack of insight (p = 0.040), and triglyceride level (p = 0.020) remained significant. The estimated 12-month area under the curve of the receiver operator characteristic (ROC-AUC) for DSH-R was 0.74 for triglycerides, 0.81 for the MINI, 0.89 for the MINI + psychosocial factors, and 0.91 for the MINI + psychosocial factors + triglycerides. The applied multifaceted approach also significantly discriminated between 12-month post-discharge DSH-R patients and other DSH patients, and a lack of insight (p = 0.047) and triglycerides (p = 0.046) remained significant for DSH-R patients in a multivariate analysis in which other DSH patients served as the reference group (rather than non-DSH patients).

CONCLUSION

The triglyceride values provided incremental validity to the MINI Suicidal Scale and psychosocial risk factors in the assessment of the risk of repeated DSH. Therefore, a bio-psychosocial approach appears promising, but further research is necessary to refine and validate this method.

Plasma total cholesterol in psychiatric patients after a suicide attempt and in follow-up

BACKGROUND

Low plasma total cholesterol (TC) levels have been found in subjects after a suicide attempt in most studies. Other studies question these results because of possible influences on TC of somatic effects due to the attempt (drugs, somatic trauma, hospitalization), or nutritional habits and physical activity before attempt, especially in patients with depression.

METHODS

To address this issue, TC levels were estimated in 51 subjects on admission to psychiatric clinic after a suicide attempt, as well as later in follow-up when patients were back in their normal activities. Patients were evaluated for suicide intent (SIS), aggression, and severity of depression (BDI).

RESULTS

A small (7% in the mean) but statistically significant increase in plasma cholesterol levels was observed in samples taken in follow-up compared to samples after attempt. However, TC levels of patients were significantly lower than controls in both assessments. There were no differences in TC between violent and non-violent attempters, either after attempt or in follow-up. In the subgroup of patients with major affective disorder, TC levels were lower compared to age-matched controls in both assessments, although patients showed significant reductions in BDI score in follow-up. In this subgroup, TC levels after attempt correlated negatively to SIS score.

CONCLUSIONS

TC levels in psychiatric patients after a suicide attempt are lower than healthy controls and remain low in follow-up, independently from the severity of psychopathology. The results support the role of plasma total cholesterol as a biological risk factor in suicidal behavior, especially in affective patients.

Obesity and suicide risk in adults--a systematic review

BACKGROUND

There is evidence from prospective studies that obesity is positively associated with depression. In contradiction to this, however, a number of studies have revealed that the number of completed suicides decreases with increasing BMI. The objective of this systematic review is to elucidate this ambiguous research field, providing an overview of literature examining the relationship between obesity and risk of suicide in adults (>18 years).

METHODS

Literature searches of the databases PubMed/Medline, PsychInfo, and Web of Sciences were conducted. Fifteen studies concerning completed suicide, suicide attempts and suicidal ideation met the inclusion criteria (seven prospective and eight cross-sectional studies).

RESULTS

Eight studies evaluating completed suicide reported an inverse relationship between BMI and suicide, meaning that obese people are less likely to commit suicide than people of low or normal weight, whereas one study showed no association and one showed a positive association. Studies about suicide attempts and ideation, on the other hand, found results that differed depending on gender. While obese woman reported more suicide attempts and suicidal ideation, obese men reported less attempts and thoughts.

DISCUSSION

The role of confounding variables such as age or psychiatric illness on suicide risk are discussed and remaining research questions are outlined, especially regarding the role of different underlying biological pathways and consideration of different classes of obesity.

NEUROBIOLOGICAL ASPECTS OF SUICIDE AND SUICIDE ATTEMPTS IN BIPOLAR DISORDER

Suicide and bipolar disorder (BD) are challenging, complex, and intertwined areas of study in contemporary psychiatry. Indeed, BD is associated with the highest lifetime risk for suicide attempt and completion of all the psychiatric conditions. Given that several clinical risk factors for both suicide and BD have been well noted in the literature, exploring the neurobiological aspects of suicide in BD may provide insights into both preventive measures and future novel treatments. This review synthesizes findings regarding the neurobiological aspects of suicide and, when applicable, their link to BD. Neurochemical findings, genes/epigenetics, and potential molecular targets for current or future treatments are discussed. The role of endophenotypes and related proximal and distal risk factors underlying suicidal behavior are also explored. Lastly, we discuss the manner in which preclinical work on aggression and impulsivity may provide additional insights for the future development of novel treatments.

The Relationships between Cholesterol and Suicide: An Update

Cholesterol is a core component of the central nervous system, essential for the cell membrane stability and the correct functioning of neurotransmission. It has been observed that cholesterol may be somewhat associated with suicidal behaviours. Therefore, the aim of this paper was to elucidate current facts and views about the role of cholesterol levels in mood disorders. The majority of the studies reviewed in the present paper suggest an interesting relationship between cholesterol (especially lower levels) and suicidality. On the other hand, particularly during the last years, relationships between serum cholesterol and suicidality were doubted on the basis of some recent studies that have not found any correlation. However, the debate on relationships between cholesterol and suicide is open and longitudinal studies on a larger sample of patients are needed to further clarify this important issue.

Measurement of total serum cholesterol in the evaluation of suicidal risk

BACKGROUND

Many studies have demonstrated an association between suicidal behavior and low levels of total serum cholesterol. To our knowledge, this association has mainly been reported in men. This case-control study was undertaken to assess the association between serum cholesterol level and suicide attempts in both genders.

METHODS

A total of 3207 subjects was included, divided into three groups: 510 patients with a history of suicidal attempts, 275 patients with no history of suicidal attempts, and 2422 controls. Mean and quartile total cholesterol levels were compared between the three groups according to gender. ROC curves were drawn to determine the biologically relevant threshold.

RESULTS

After adjustment for age, cholesterol level was significantly lower (p<0.01) in suicide attempters than in non-attempters and controls for both genders. Male non-suicide attempters had similar cholesterol levels to controls (p=0.7), but the levels in female non-attempters were significantly higher (p=0.004). The proportion of suicide attempters in the lowest cholesterol level quartile (51.3% of men, 40.1% of women) was significantly higher than that in the highest quartile (8.1% of men, 12.4% of women). For triglyceride level, no difference was found between the three groups, suggesting that this association was not due to malnutrition linked to depression.

LIMITATIONS

The effect of acute or chronic administration of medications on serum cholesterol levels was not controlled. Psychiatric history in surgical controls was not recorded.

CONCLUSIONS

Total serum cholesterol levels measured at admission may be a useful biological marker of suicidal risk.

Thrombocyte serotonin and serum cholesterol concentration in suicidal and non-suicidal depressed patients

INTRODUCTION

Numerous studies have confirmed the connection of reduced serum cholesterol and thrombocyte serotonin concentration with suicidal behavior in psychiatric patients. The purpose of such studies was to determine the link among cholesterol and serotonin concentration, comparing depressed patients with and without attempted suicide with phenotypically healthy control group.

MATERIALS AND METHODS

The examinees' groups consisted of 55 depressed patients with suicide attempt and 77 depressed patients with no suicide attempt. In accordance to ICD-10, the above patients were separated in two subgroups; F32.2 and F33.2. Phenotypically healthy control group was presented by the group of healthy blood donors. The fasting serum cholesterol concentration was established using standard enzymatic method, while the thrombocyte serotonin concentration was determined by the enzymatic immune-chemical method (ELISA).

RESULTS

The ANOVA test (N=228, F(ratio)=8.26, p<0.001) found significant difference of cholesterol concentration between groups, with lowest concentration in depressed patients with attempted suicide (SNK post hoc test, p<0.05). Upon gender stratification, the significance remained for the female patients (ANOVA, N=125, F(ratio)=6.06, p=0.003). The serum cholesterol was shown to be statistically lower in the group of depressed patients with attempted suicide, diagnoses F32.2 (p=0.031) and F33.2 (p=0.011), compared to the group of depressed patients without attempted suicides. The thrombocyte serotonin was found to be significantly different in all examined groups, with the lowest thrombocyte serotonin in the group of depressed patients with no suicide attempt (SNK post hoc test, p<0.05, N=187, F(ratio)=37.69, p<0.001). The same significance was found for the group of female (ANOVA, N=103, F(ratio)=11.81, p<0.001) and the group of male patients (ANOVA, N=84, F(ratio)=30.40, p<0.001). The thrombocyte serotonin was significantly lower in the group of depressed patients with no suicide attempt (F32.2), compared to the same diagnosis in the group of depressed patients with suicide attempt (MW-test, p=0.018).

CONCLUSION

In the group of depressed patients with attempted suicide, statistically significant lower serum cholesterol values have been confirmed. In the group of depressed patients with no suicide attempt, statistically significant lower values of thrombocyte serotonin have been confirmed, presumably as the response to the psychopharmacological therapy.

Potential peripheral biological predictors of suicidal behavior in major depressive disorder

Previous studies have shown that dysfunctions in the serotonin system and hypothalamic-pituitary-adrenal axis (HPA) are associated strongly with suicidal behavior and suicide, especially among individuals with major depressive disorder. Suicidal behavior has been explained using both the stress-diathesis model and the state-trait interaction model. Specifically, diatheses, or trait-dependent risk factors, are associated with dysfunctions in the serotonin system; however, stress responses, or state-dependent factors, are associated with HPA hyperactivity. Decreases in cholesterol and brain-derived neurotrophic factor (BDNF) levels have been associated with impaired brain plasticity among individuals with suicidal behavior. Decreased serotonin functioning has been measured using cerebral spinal fluid (CSF) 5-HIAA, fenfluramine challenge studies, and platelet 5-HT2A receptors. HPA axis dysfunction has been evaluated with the dexamethasone suppression test. Cholesterol and BDNF levels have been measured in blood serum or plasma. Nevertheless, challenges to finding promising and accessible neurobiological predictors of suicide and suicidal behavior remain. As suicide behavior is a complex phenomenon, a combined or multidimensional approach, including each of the aforementioned methods, may be required to predict suicide risk among individuals with major depressive disorder.

A prospective study of lipids and serotonin as risk markers of violence and self-harm in acute psychiatric patients

Cross-sectional studies have reported an association between lipids and serotonin levels and aggression, but a literature search revealed a paucity of prospective studies. Subjects of the present naturalistic study were 254 of all (489) involuntary and voluntary acutely admitted patients to a psychiatric hospital during 1year. Serum lipids and platelet serotonin at admission were prospectively compared with recorded intra-institutional and 1-year post-discharge violence and self-harm. Total cholesterol had a significant negative relationship to inpatient suicidal behaviour and inpatient violent behaviour and to 3-month post-discharge violent behaviour. Triglycerides were a significant marker of inpatient self-mutilation and of self-mutilation in combination with suicidal behaviour at 3 and 12 months of follow-up. High-density lipoprotein (HDL) had a significant negative relationship to violence at 12-months, and to repeated violence in seven patients with two or more admissions. The post-discharge relationships between total cholesterol and violence and between triglycerides and self-harm remained significant even when controlling for other possible explanatory variables in a multivariate model. Results did not change after controlling for current medication at admission. There was no association between platelet serotonin and violence or self-harm. Future research may examine if lipid measurements add incremental validity to established clinical risk assessment procedures of violent and self-harm behaviour.

Cholesterol and CSF 5-HIAA in attempted suicide

BACKGROUND

Low serum cholesterol has been linked to suicide and violent behaviour. The same kind of associations has been reported regarding low levels of 5-hydroxyindolacetic acid (5-HIAA) in the cerebrospinal fluid (CSF) and suicidal behaviour. The hypothesis of the link between serum cholesterol and suicide incorporate serotonin. It proposes that low cholesterol is related to altered serotonergic neurotransmission. A correlation between CSF 5-HIAA and serum cholesterol has been shown in animal studies, but has not been found in humans.

AIM

To study the interrelationship between serum cholesterol and CSF 5-HIAA in suicide attempters. Since both cholesterol and CSF 5-HIAA are associated with suicide and violent suicide attempts, we also investigated the correlation with suicide, violent suicide attempt method, suicide intent, hopelessness and depression severity.

METHODS

Serum total cholesterol and CSF 5-HIAA were measured in 42 medication free suicide attempters. Patients were assessed with Becks's Hopelessness scale (BHS), Suicide Intent Scale (SIS) and Montgomery-Asberg depression rating scale (MADRS) and followed-up for causes of death.

RESULTS

Serum total cholesterol and CSF 5-HIAA showed a significant positive correlation adjusted for age, body mass index and substance abuse diagnosis. Cholesterol and CSF 5-HIAA levels did not differ between violent and non-violent suicide attempters or between suicide completers and survivors.

CONCLUSIONS

These findings indicate that the serotonergic system may be connected to serum cholesterol in patients with a recent suicide attempt.

Evolving refractory major depressive disorder diagnostic and treatment paradigms: toward closed-loop therapeutics

Current antidepressant therapies do not effectively control or cure depressive symptoms. Pharmaceutical therapies altogether fail to address an estimated 4 million Americans who suffer from a recurrent and severe treatment-resistant form of depression known as refractory major depressive disorder. Subjective diagnostic schemes, differing manifestations of the disorder, and antidepressant treatments with limited theoretical bases each contribute to the general lack of therapeutic efficacy and differing levels of treatment resistance in the refractory population. Stimulation-based therapies, such as vagus nerve stimulation, transcranial magnetic stimulation, and deep brain stimulation, are promising treatment alternatives for this treatment-resistant subset of patients, but are plagued with inconsistent reports of efficacy and variable side effects. Many of these problems stem from the unknown mechanisms of depressive disorder pathogenesis, which prevents the development of treatments that target the specific underlying causes of the disorder. Other problems likely arise due to the non-specific stimulation of various limbic and paralimbic structures in an open-loop configuration. This review critically assesses current literature on depressive disorder diagnostic methodologies, treatment schemes, and pathogenesis in order to emphasize the need for more stringent depressive disorder classifications, quantifiable biological markers that are suitable for objective diagnoses, and alternative closed-loop treatment options tailored to well-defined forms of the disorder. A closed-loop neurostimulation device design framework is proposed, utilizing symptom-linked biomarker abnormalities as control points for initiating and terminating a corrective electrical stimulus which is autonomously optimized for correcting the magnitude and direction of observed biomarker abnormality.

Suicide neurobiology

In this review, we examine the history of the neurobiology of suicide, as well as the genetics, molecular and neurochemical findings in suicide research. Our analysis begins with a summary of family, twin, and adoption studies, which provide support for the investigation of genetic variation in suicide risk. This leads to an overview of neurochemical findings restricted to neurotransmitters and their receptors, including recent findings in whole genome gene expression studies. Next, we look at recent studies investigating lipid metabolism, cell signalling with a particular emphasis on growth factors, stress systems with a focus on the role of polyamines, and finally, glial cell pathology in suicide. We conclude with a description of new ideas to study the neurobiology of suicide, including subject-specific analysis, protein modification assessment, neuroarchitecture studies, and study design strategies to investigate the complex suicide phenotype.

Low serum cholesterol and external-cause mortality: potential implications for research and surveillance

OBJECTIVE

Previous studies suggested that low total cholesterol was associated with external mortality, including deaths from suicide, homicide, and accidents. However, this reported association was potentially confounded, since cholesterol was also reported to be associated with alcohol abuse, anti-social personality disorder, and other risk factors for external mortality.

METHOD

We examined external-cause mortality among a national sample of 4462 male, US veterans at baseline in 1985. Using Cox regressions to estimate survival time, we assessed the impact of low baseline total cholesterol < or =165 mg/dl, age, race, intelligence, BMI, alcohol abuse, anti-social personality disorder, depression, and other factors at follow-up. Study follow-up continued until December 31, 2000. A total of 55 external mortalities occurred during this approximately 16-year period.

RESULTS

Multivariate Cox regressions predicting external-cause mortality suggested that three predictor variables were significant: low total cholesterol, morbid depression, and anti-social personality disorder, with hazard ratios (HRs) of 1.97 (p=0.046), 1.76 (p=0.043), and 2.22 (p=0.006), respectively. In addition, a significant interaction was detected for low cholesterol x morbid depression (p<0.005), whereby those with both at baseline were approximately 7 times more likely to die from external mortality (HR=6.5, 95% CI=3.07-13.76).

CONCLUSION

Among a national random sample of community-based men, lower baseline cholesterol predicted external mortality and revealed an interaction with morbid depression. Patients presenting with low cholesterol and morbid depression in clinical practice may warrant clinical attention and surveillance.

Serum lipid levels and suicidality among male patients with schizoaffective disorder

Suicidal behavior in schizoaffective disorder is a serious problem and suicide risk during lifetime ranges between 5%-10%. Neurobiology of suicidal behavior has not been studied sufficiently, and a high number of studies are oriented toward lipid investigation. The aim of our study was to investigate whether there were differences in the level of lipids (cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides) in hospitalized suicidal (n=20) and non-suicidal (n=20) patients with schizoaffective disorder. The study also included male healthy control subjects (n=20). Hamilton Depression Rating Scale (HDRS-17), and Positive and Negative Syndrome Scale (PANSS) were used to confirm the level of psychopathology in patients with schizoaffective disorder. Severity of suicidality was measured by Scale for Suicide Ideation (SSI) at time of admission. Results of the study indicated significantly lower concentrations of cholesterol (p<0.001), LDL-cholesterol (p<0.01) and HDL-cholesterol (p<0.01). There were no differences in the number of previous hospitalization and previous suicide attempts between suicidal and non-suicidal patients (p>0.05). Duration of the illness was significantly (p<0.05) shorter in suicidal patients. Suicidal patients also had a significantly higher score on HDRS-17 (p<0.001) and PANSS (p<0.01) compared to non-suicidal patients.

Evaluation of Serum Ghrelin and Leptin Levels in Suicide Attempters

Previous studies have reported a relationship between cholesterol and leptin levels, and suicide attempts, impulsivity, and aggressive behaviors. An orexigenic hormone seems to be strongly associated with lipid metabolism and leptin levels. Therefore, we aimed to compare serum cholesterol, leptin, and ghrelin levels in 36 patients with suicide attempts and 25 healthy controls. Patients with suicide attempts had decreased leptin levels and significantly higher ghrelin levels compared to healthy controls. While the serum ghrelin level did not show any correlation with the demographic and clinical factors, leptin showed a correlation with body mass index (BMI), and cholesterol levels were correlated with the age, BMI, and number of suicide attempts in the suicidal group. The results suggest that suicide attempts seem to be related with higher serum ghrelin values, decreased leptin, and cholesterol levels.

Cholesterol and suicide attempts: a prospective study of depressed inpatients

Low cholesterol levels have commonly been associated with various suicide measures. We sought to examine suicide attempts in a prospective sample of depressed patients that on prior analysis demonstrated an association between low cholesterol and subsequent suicide completions. Seventy-four inpatients with Research Diagnostic Criteria unipolar major depression, bipolar depression or schizoaffective depression entered a prospective follow-up study from 1978 to 1981. Kaplan-Meier survival analysis and Cox regression were utilized to elucidate the relationship between cholesterol levels and subsequent severe suicide attempts as well as all suicide attempts regardless of severity. Attempts preceding index hospitalization and other lifetime attempts were evaluated cross-sectionally. Low serum cholesterol levels did not predict subsequent suicide attempts. Contrary to our hypothesis, the high cholesterol group was associated with increased risk of suicide attempts on survival analysis in those less than median age. Nonetheless, in cross-sectional analysis, the low cholesterol group had more suicide attempts preceding index hospitalization and more remote lifetime attempts. The results from this prospective dataset do not support an association between low cholesterol and subsequent suicide attempts despite replicating the retrospective findings of previous case-control and cross-sectional studies.

Combined biological tests for suicide prediction

Disturbances in serotonin neuroregulation and in hypothalamic-pituitary-adrenal axis activity are both likely, and possibly independent, factors in the genesis of suicidal behavior. This analysis considers whether clinically accessible measures of these two disturbances have additive value in the estimation of risk for suicide. Seventy-four inpatients with RDC major or schizoaffective depressive disorders entered a prospective follow-up study from 1978-1981, underwent a dexamethasone suppression test (DST) and had fasting serum cholesterol levels available in the medical record. As reported earlier, patients who had had an abnormal DST result were significantly more likely to commit suicide during follow-up. Serum cholesterol concentrations did not differ by DST result and low cholesterol values were associated with subsequent suicide when age was included as a covariate. These results indicate that, with the use of age-appropriate thresholds, serum cholesterol concentrations may be combined with DST results to provide a clinically useful estimate of suicide risk.

Lipid connection to bipolar disorder

Bipolar disorder is a severe and chronic illness affecting approximately 1.5% of the American population. Despite the availability of mood bipolarstabilizers such as lithium, valproate, carbamazepine and lamotrigine, bipolar disorder is characterized by high rates of recurrence, as treatment with these and other drugs is ineffective for and not tolerated by a significant percentage of patients. Several hypotheses have been postulated to explain the mechanism(s) of action of mood stabilizers. However, the biological and molecular bases of the disease are not fully understood, hampering the development of more effective and safer drugs. A large body of evidence associates lipids (cholesterol, phospholipids and fatty acids) with the mechanism and pathology of bipolar disorder. The purpose of this paper is to review the lipid connection to bipolar disorder.

Clinical assessment of suicide risk in depressive disorder

Efforts to identify clinical risk factors for complete suicide through the follow-up of depressed patients have yielded relatively few robust predictors. Those identified by at least three studies are (in order of decreasing frequency) suicidal plans/attempts, male sex, being single or living alone, inpatient status, and hopelessness. Because the best established of these predictors has only modest sensitivity and specificity, the need for other robust tools is clear. A rich body of research has identified two biological risk factors for suicide in depressive disorder: hypothalamic-pituitary-adrenal axis hyperactivity and deficits in serotonin function. Moreover, there is now considerable evidence that the dexamethasone suppression test and measures of serum cholesterol concentrations, respectively, may provide a clinically useful reflection of these two mechanisms. Observations that these measures appear to be additive, both with each other and with other clinical risk factors, indicate that a substantial improvement in the clinician's ability to assess suicide risk is possible.

Mental effect of cholesterol in males: protective effect?

BACKGROUND

While the benefits of low cholesterol for physical health are not in doubt, a potential negative aspect of low cholesterol for mental health is suggested by several studies. To examine the association between cholesterol and mental health, the authors performed an observational study.

METHOD

From April 1995 to March 2002, a series of questionnaires pertaining to physical activity, food consumption, alcohol, coffee, smoking, and mental health (12 item-version of General Health Questionnaire: GHQ-12) were administered to 1972 employees in Japan. Subjects with less than 150 mg/dL of total cholesterol (very low cholesterol cohort) and other subjects (control cohort) were followed up for one to six years, and their mental health compared using GHQ caseness (GHQ-12 scores more than 3).

RESULTS

Kaplan-Meier survival curves revealed that the very low cholesterol cohort had significantly greater GHQ caseness than the control cohort. Notably, this finding applied to males but not to females. After adjustment for general health, Cox's proportional hazards regression model confirmed this association in males only. The survival curves of control cohort were significantly different between males and females whereas those of very low cholesterol cohort were not.

LIMITATIONS

GHQ caseness was regarded as "death" in the survival analysis. As such, it is not possible to differentiate between transient and persistent mental dysfunction and therefore may lead to overestimation of GHQ caseness over observational years.

CONCLUSION

The present findings suggest that very low cholesterol may be associated with worse mental health in males and conversely and interestingly indicate that moderate (but not very low) cholesterol levels may protect mental health in males.

High cholesterol, triglycerides, and body-mass index in suicide attempters

Low cholesterol concentrations and cholesterol-lowering therapies have been suggested to be associated with increased suicidality. This article examined the association of cholesterol, triglycerides, and body-mass index (BMI) with suicidal ideation and suicide attempts. Findings are based on a nationally representative community sample of n = 4,181 subjects (18-65 years) examined with a standardized diagnostic interview (CIDI) for (DSM-IV) mental disorders. Controlling for age and gender the study revealed a moderate positive association between cholesterol, triglycerides, BMI, and suicide attempts in subjects with depressive symptoms during the past 12 months (n = 1,205). The results of this study are compatible with two recent epidemiological cohort studies showing a positive association between cholesterol and completed suicide.

No relationship between serum cholesterol and suicidal ideation and depression in African-American diabetics

Low serum cholesterol has been associated with suicidal behavior. Depression has been postulated to be a mediating factor between low serum cholesterol and suicidal behavior. Therefore, this possibility was examined in a large group of 459 diabetic patients that had blood drawn for serum cholesterol levels on the same day that they completed the Beck Depression Inventory. The results failed to show any significant relationship between serum cholesterol levels and either total Beck Depression Inventory (BDI) scores or BDI scores on the item measuring current suicidal ideation. The limitations of the study are discussed.

Reductions in cholesterol and synaptic markers in association cortex in mood disorders

OBJECTIVES

Cholesterol forms an integral part of cell membranes and is a major component of myelin. Furthermore, cholesterol also plays a vital role in the development, function and stability of synapses. While low serum cholesterol has previously been associated with mood disorders, cholesterol levels have yet to be quantified within the brain in these disorders. The aim of this study was to quantify sterol levels in the brains of patients with major psychiatric disorders and further to relate these levels to markers of myelin and synapses.

METHODS

Samples of visual association cortex were obtained postmortem from subjects with bipolar disorder (BPD), major depressive disorder (MDD) and schizophrenia (SCZ) and from controls (all n = 15). Concentrations of brain cholesterol, its precursors lathosterol, desmosterol and lanosterol and its metabolite 24S-hydroxycholesterol were determined by gas-liquid chromatography. Immunoreactivity for myelin basic protein (MBP), synaptophysin and VAMP was quantified by enzyme-linked immunosorbent assay.

RESULTS

Cholesterol levels were 13% lower in MDD (p = 0.018) and 10% lower in BPD (p = 0.052) compared with controls. Cholesterol precursor or metabolite concentrations did not differ between groups. Synaptophysin immunoreactivity was 20% lower in BPD (p = 0.025) and VAMP immunoreactivity 37% lower in MDD (p = 0.032) and 45% lower in BPD (p = 0.009). MBP immunoreactivity was not altered in any disorder.

CONCLUSIONS

Our data suggest that lower brain cholesterol levels and a reduction in synapses may be features of mood disorders.

Serum lipid profiles in major depression with clinical subtypes, suicide attempts and episodes

BACKGROUND

We tried to report the data between serum lipid profiles and major depression with different clinical subtypes, with or without suicide attempts, and with single episode or recurrent episodes.

METHOD

During a 2-year period, a total of 168 participants (109 patients with major depression and 59 subjects in a healthy control group) were recruited in this study. Blood samples for serum lipid profiles in all participants were collected. Data analysis was performed by using an analysis of covariance (ANCOVA) with body mass index (BMI) adjustment.

RESULTS

The data showed that there were no significant differences of any kind in serum lipid profiles between depressive patients with melancholic feature or atypical feature, with or without suicide attempts nor between depressive patients with single episode or recurrent episodes.

CONCLUSION

The results suggested there were no serum lipid profiles used as biological markers to distinguish the clinical subtypes, suicide attempts and episodes in patients with major depression.