Low serum cholesterol in violent but not in non-violent suicide attempters

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.

Prediction of Suicidality According to Serum Folate Levels in Depressive Patients Receiving Stepwise Pharmacotherapy

Background: The effects of serum folate levels on suicidal behavior, strongly associated with depression, have not been investigated. Therefore, this study investigated the associations between serum folate levels and suicidal behavior in patients with depressive disorders. Methods: Serum folate levels were measured at baseline in 1,094 patients with depressive disorder, 884 of whom were followed during a 12-month period of stepwise pharmacotherapy. Suicidal behaviors evaluated at baseline were (i) previous suicide attempt and (ii) baseline suicidal severity; behaviors evaluated at follow-up were (iii) increased suicidal severity and iv) fatal/non-fatal suicide attempt. Associations of serum folate levels with four types of suicidal behaviors were analyzed using logistic regression models after adjustment for relevant covariates; they were also examined using area under receiver operating characteristic (AUROC) curve analyses. Results: Reduced serum folate levels (<6.0 ng/mL) were independently associated with all four types of suicidal behaviors. AUROC curve analyses indicated that discriminant or prognostic values of reduced serum folate levels were fair for fatal/non-fatal suicide attempt during follow-up, whereas they were modest for previous suicide attempt, baseline suicidal severity, and increased suicidal severity. Conclusions: Serum folate levels could serve as a biomarker of suicidal behavior in depressive patients. However, it should be used as an adjunct rather than a substitute for prediction of suicidal behavior considering its low prognostic values. Further replication studies are needed for its clinical utilization.

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.

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.

Low total cholesterol and low-density lipoprotein associated with aggression and hostility in recent suicide attempters

Low cholesterol levels have been correlated with both suicidal and aggressive behavior in psychiatric patients. Few studies have investigated associations between serum lipid profiles and both aggressive state and trait. Fifty-two psychiatric medication-free inpatients were included in this study after a suicide attempt. Composite scores of "State Aggression" and "Trait Aggression" were calculated using relevant items from the Comprehensive Psychopathological Rating Scale and the Karolinska Scales of Personality. State Aggression was significantly and negatively correlated with total cholesterol (TC) and low-density lipoprotein (LDL). Trait Aggression was also significantly and negatively correlated with LDL, but not TC. There were small but significant mediation effects of severity of anxiety symptoms on the relationship between State Aggression and TC as well as LDL. In exploratory analyses we found that low cholesterol was also associated with personality traits of hostility. Moreover, low cholesterol was more robustly associated with personality trait items related to interpersonal aggression, as opposed to items related to irritability or more indirect, non-overt aggression. Our findings suggest that low cholesterol is associated with both state and trait aggression in suicide attempters. Future mechanistic studies are warranted to better understand the relationship between low cholesterol and high aggression in suicide attempters.

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.

Mean platelet volume and neutrophil to lymphocyte ratio as parameters to indicate the severity of suicide attempt

This study was designed to compare the complete blood count (CBC) values of 38 violent suicidal attempt (VSA) and 38 nonviolent suicidal attempt (NVSA) patients and 38 healthy controls, particularly mean platelet volume (MPV) and neutrophil to lymphocyte ratio (NLR). MPV was found to be significantly higher (P = 0.000), and PLT was found to be significantly lower in the VSA group (P = 0.001). NLR was found to be significantly higher (P = 0.005) in the VSA group. The area under the receiver operating characteristic curve of MPV levels for VSA was 0.78 and 0.68 for NLR in the VSA group when compared with the NVSA group.

Suicidal behaviour is associated with decreased esterified cholesterol in plasma and membrane fluidity of platelets

BACKGROUND

Altered cholesterol levels in body fluids and brain tissues have been shown to be associated with suicidal behaviour, violence and aggression. But the biological underpinnings of this association in the pathophysiology of suicide are not clear. Cholesterol plays a crucial role in maintaining the cellular membrane fluidity and alterations in cellular membrane fluidity may impair serotonergic neurotransmission in the central nervous system.

METHODS

We measured plasma esterified cholesterol and platelet membrane fluidity using fluorescence anisotropy and estimated flow activation energy which is a measure of order of membrane lipid bilayer in patients with recent suicidal attempt and compared with age and gender matched controls.

RESULTS

The plasma esterified cholesterol, platelet membrane fluidity and flow activation energy was found to be significantly lower in patients with recent suicidal attempts compared to controls.

CONCLUSION

Altered levels of plasma esterified cholesterol which is in equilibrium with membrane cholesterol might have resulted in decreased membrane fluidity and an increase in the order of membrane lipid bilayer. This might impair the serotonergic neurotransmission, which has been implicated in the pathophysiology of suicide.

The concept of violent suicide, its underlying trait and neurobiology: A critical perspective

Suicide is one of the leading causes of death and represents a significant public health problem world-wide. Individuals who attempt or die by suicide represent a highly heterogeneous population. Recently, efforts have been made to identify sub-populations and variables to categorize them. A popular dichotomy in suicide research of the past years is violent versus non-violent suicide - based on the method. This dichotomy is important given that there is an association between method of attempted suicide and risk of subsequent death by suicide. The differentiation concerning suicide methods is also critical regarding preventive efforts. In this review, we have tried to approach the concept of violent suicide from different perspectives, including a discussion about its definition and overlapping categories. In addition, we have critically discussed aggression as underlying trait, the question of intent to die, and sociodemographic, environmental, neuropsychological, and neurobiological factors potentially associated with violent suicide.

CSF Apolipoprotein E in attempted suicide

BACKGROUND

Cholesterol and cholesterol metabolism, involved in continued neural plasticity, has been associated to suicide and suicidal behavior. Apolipoprotein E (ApoE) plays an important role in the cholesterol metabolism. The purpose of this study was to investigate whether ApoE in cerebrospinal fluid was related to severity of suicidal behavior as measured by number of earlier suicide attempts, reversibility/interruptabilty and violent method of suicide attempt.

METHODS

CSF ApoE and 5-hydroxyindolacetic acid (5-HIAA) were measured in 42 medication free suicide attempters. Earlier suicide attempts and the reversibility of suicide attempt method were assessed with the Suicide Intent Scale (SIS) and the Freeman Scale. Suicide attempts were classified according to violence of method.

RESULTS

CSF ApoE levels significantly negatively correlated to the scores on Freeman Reversibility and there was a trend for lower CSF ApoE levels in suicide attempters using a violent method. Patients with at least one earlier suicide attempt (repeaters) showed a trend for higher CSF ApoE levels compared to suicide attempters debuting with suicidal behavior at inclusion in the study. The correlation between CSF ApoE and 5-HIAA was not significant.

LIMITATIONS

The main limitations to this study were a relatively small sample size and lack of a healthy control group.

CONCLUSION

Irreversible suicide attempts, representing a high risk for completed suicide, may be associated with lower level of ApoE in CSF.

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.

Associations between serum lipid levels and suicidal ideation among Korean older people

INTRODUCTION

There have been inconsistent reports on the relationships between lipids and suicidality, and studies conducted in older adults are rare. This study examined associations between serum lipid levels and suicidal ideation in an older population.

METHODS

This study used data obtained from a representative Korean sample of 4265 people age 65 years or older who completed a self-administered questionnaire about suicidal ideation over the last year. The fasting serum concentrations of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides were measured and categorized into lower, intermediate (reference), and upper quartiles. A complex sample logistic regression stratified by gender was performed to determine the associations between serum lipid levels and suicidal ideation after controlling for covariates including age, education, marital status, current smoking, alcohol drinking, body mass index, hypertension, diabetes, diagnosed depression, antidepressant use, and lipid-lowering therapies.

RESULTS

In this study, the prevalence of suicidal ideation in an older Korean population was 22.9% (SE=0.9%). The prevalence was significantly higher in women than in men, 27.7% (1.2%) vs. 15.9% (1.1%) respectively. After adjusting for covariates, lower triglyceride levels were significantly associated with a decreased risk of suicidal ideation (OR=0.65; 95% CI=0.43-0.99) among men but no significant associations were observed among women. Additionally, there were no significant associations between any other measure of cholesterol levels and suicidal ideation in either men or women.

LIMITATIONS

Cross-sectional design cannot infer temporality or the effects of changes in variables.

CONCLUSIONS

These results support the association between lower triglyceride levels and a reduced risk of suicidal ideation among Korean men over 65. Further studies are necessary to investigate gender difference and the biological mechanism.

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.

Exploring the Determinants of Suicidal Behavior: Conventional and Emergent Risk (DISCOVER): a feasibility study

BACKGROUND

Suicidal behavior is a growing public health concern resulting in morbidity and premature death. Although certain factors such as age, sex, and psychiatric disorders have been consistently reported to be associated with suicidal behavior, other factors including biological markers, diet, and physical activity may also influence suicidal behavior. The purpose of this pilot study was to evaluate the feasibility of conducting a full-scale study to identify the conventional and novel risk factors of suicidal behavior in individuals who made a recent suicide attempt.

METHODS

This pilot study was a case-control study of participants with recent (within 1 month of admission) suicide attempts admitted to hospital and compared to two control groups: 1) psychiatric inpatient participants without a history of suicide attempts and 2) community-based controls. We collected information on demographic variables, circumstances of suicide attempts (for cases), medical and psychiatric diagnoses, behavioral patterns, physical measurements, and social factors. Blood and urine samples were also collected for biological markers. Feasibility outcomes are as follows: 1) 50 % of all eligible cases will consent to participate, 2) 50 cases and 100 controls per year can be recruited, and 3) at least 80 % of the participants will provide blood samples for DNA and biological markers.

RESULTS

We recruited 179 participants in total; 51 cases, 57 psychiatric controls without suicide attempt, and 71 non-psychiatric controls in Hamilton, Ontario. Recruitment rate was 70 % (213/304), and we obtained urine and blood specimens from 90 % (191/213) of participants. Questionnaire completion rates were high, and data quality was very good with few data-related queries to resolve. We learned that cases tended to be hospitalized for long periods of time and the suicide attempt occurred more than a month ago in many of the cases; therefore, we expanded our inclusion criterion related to timing of suicide attempt to 3 months instead of 1 month.

CONCLUSIONS

The study procedures needed certain modifications including extending the time between suicide attempt and date of recruitment, and more detailed questionnaires related to diet were necessary while other questionnaires such as social support needed to be shortened. Overall, this study showed that it is feasible to conduct a larger-scale study.

An association study of suicide and candidate genes in the serotonergic system

INTRODUCTION

Strong evidence demonstrates a genetic susceptibility to suicidal behaviour and a relationship between suicide and mental disorders. The aim of this study was to test for association between suicide and five selected genetic variants, which had shown association with suicide in other populations.

METHOD

We performed a nationwide case-control study on all suicide cases sent for autopsy in Denmark between the years 2000 and 2007. The study comprised 572 cases and 1049 controls and is one of the largest genetic studies in completed suicide to date. The analysed markers were located within the Serotonin Transporter (SLC6A4), Monoamine Oxidase-A (MAOA) and the Tryptophan Hydroxylase I and II (TPH1 and TPH2) genes.

RESULTS

None of the genetic markers within SLC6A4, MAOA, TPH1 and TPH2 were significantly associated with completed suicide or suicide method in the basic association tests. Exploratory interaction test showed that the minor allele of rs1800532 in TPH1 has a protective effect for males younger than 35 years and females older than 50 years, whereas for the oldest male subjects, it tended to be a risk factor. We also observed a significant interaction between age-group and the 5-HTTLPR genotype (with and without rs25531) in SLC6A4. The long allele or high expression allele tends to have a protective effect in the middle age-group.

LIMITATION

We only analysed a limited number of genetic variants.

CONCLUSION

None of the analysed variants are strong risk factors. To reveal a better understanding of the genes involved in suicide, we suggest future studies should include both genetic and non-genetic factors.

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.

CNS regulation of plasma cholesterol

The incidence of disorders related to the control of energy homeostasis, such as hypertension, diabetes, obesity, and dyslipidemia, has dramatically increased worldwide in the last decades. The central nervous system (CNS) plays a critical role regulating the energy balance, therefore there has been increasing interest in understanding the mechanisms whereby the brain controls peripheral metabolism, in order to develop new potential therapies to treat those disorders. While the involvement of the CNS in development of hypertension, obesity, and diabetes has been thoroughly investigated, less is known about the specific role of the brain in the control of circulating lipids. Here we summarize the evidence linking CNS disorders with dyslipidemia, as well as the central mechanisms that directly influence plasma cholesterol.

Serum lipids, metabolic syndrome and lifetime suicide attempts in patients with bipolar disorder

OBJECTIVE

Bipolar disorder is associated with a high risk of suicide. Many clinical characteristics and, recently, biomarkers have been studied with the aim to find useful predictors of suicidality. The role of serum lipids has also been explored albeit with conflicting results; however, few studies have been focused on patients with bipolar disorder. Aim of our study is to investigate whether serum cholesterol, triglycerides, HDL-c and metabolic syndrome are associated with lifetime suicide attempts in a large naturalistic sample of patients with bipolar disorder.

METHODS

220 patients with bipolar disorder were included. History of lifetime suicide attempts was systematically and retrospectively assessed for each patient. Blood exams testing total cholesterol, triglycerides, and HDL-c levels were performed, and metabolic syndrome was diagnosed according to NCEP ATP-III modified criteria. Serum lipid levels and metabolic syndrome were compared in patients with or without history of suicide attempt. According to a theory that links impulsivity and violence with low cholesterol, the association between lipid levels and violent suicidal behavior was also assessed.

RESULTS

Lifetime suicide attempts rate was 32.3%. There were no statistically significant differences between patients with and without lifetime suicide attempts in cholesterol, triglycerides, HDL-c levels, and the prevalence of metabolic syndrome. No differences in the same variables were found in violent suicide attempters compared with nonviolent ones. Clinical characteristics such as gender, low education, higher number of manic and depressive episodes, and taking more medications for bipolar disorder were associated with lifetime suicide attempts.

CONCLUSIONS

Our results do not support the hypothesis of a strong association between serum lipid levels and suicide in patients with bipolar disorder.

[Suicide and nutrition: a bio-psychosocial approach]

This article proposes a new bio-psychosocial perspective on the links between mental health, more specifically suicide, and nutrition. We first discuss the links between nutrition, its social role and suicide. The act of eating is studied as a social integrator and regulator, in the light of Durkheim's theorization. Nutrition is also examined as self-destruction, with particular cases of "diet-related suicide." De-structuring of meals and alienating foods are identified as contributing factors to the de-structuring of "nutrition models." We then discuss the place of food within the psychopathology, and finally, the links between biological parameters reflected in food and suicide risk. Avenues of research and intervention along this bio-psychosocial approach are also proposed.

Changes in rates, methods and characteristics of suicide attempters over a 15-year period: comparison between Stockholm, Sweden, and Würzburg, Germany

PURPOSE

To investigate age and sex-specific changes in rates, methods used and characteristics of suicide attempters receiving medical care, over a 15-year period in two European WHO catchment areas (Stockholm, Sweden; and Würzburg, Germany).

METHODS

The data for this study were obtained from the WHO/EURO Multicentre Study on Suicidal Behaviour for the period 1989-2003. Sex-specific, person-based suicide attempt rates were calculated for each year separately for the age groups 15-24 and 25 or above. The Chi-square test for trend was applied to estimate changes in proportions of socio-demographic and socio-economic variables.

RESULTS

Significantly, increasing trends in suicide attempt rates occurred in young females, and in males and females aged 25 or above in Würzburg. On the contrary, men 25 years and above showed a significant decrease in suicide attempt rates in Stockholm. Young females in Würzburg tended to use less violent methods for their attempts whereas in Stockholm young females were increasingly inclined to attempt suicide using violent methods. In Stockholm, young female suicide attempters tended to be more often economically inactive, particularly due to an increasing proportion of students. Young females in Würzburg were often less well educated, as were their young male counterparts. This contrasted with trends in the education of men and women of 25 or above in Stockholm.

CONCLUSIONS

The results of this study suggest temporal changes in trends, methods used and in the social profile of suicide attempters.

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.

Characteristics of young suicides by violent methods in rural China

Suicide is one of the most common public health problems in the world. Information on 392 completed suicides aged 15-34 years were consecutively collected from 16 counties in three provinces of China. Information on each suicide was obtained from two informants. The results showed ingesting pesticides or other poisons (73.5%) and hanging (10.5%) were the two most common methods of suicide. Suicides happened more in autumn (30.10%) or summer (27.29%), nighttime (68.3%), and at home (73.6%). However, suicides with violent methods were more common in winter and spring and outside of home. Season (autumn or summer), place (at home), and pesticide stored in home were negatively while depression was positively associated with violent methods of suicide. Characteristics of the suicides by violent methods are different from those by nonviolent methods. Investigations into the methods of rural young suicides are necessary for suicide prevention in China.

Cholesterol concentrations and clinical response to sertraline in patients with epilepsy: preliminary results

OBJECTIVE

Low cholesterol levels are associated with depression and suicide in persons with epilepsy. The goal of this study was to determine whether plasma cholesterol concentration is a predictor of response to sertraline.

METHODS

We carried out a prospective open-label study on the efficacy of sertraline as therapy in the treatment of depressive disorder in patients with mesial temporal lobe epilepsy. Patients were treated for 24 weeks at dose levels between 50 and 100mg/day. All patients were evaluated at the beginning of the investigation and 6 months later by two psychiatrists using a structured interview.

RESULTS

The mean total cholesterol concentration of nonresponding patients was lower than the mean (SD) cholesterol level of responders [3.2 (0.9) mmol/L vs 5.2 (1.5) mmol/L]; this difference reached statistical significance (P = 0.0000). We found a negative correlation between scores on the Hamilton scale and cholesterol concentrations (r = -33).

CONCLUSION

The response to sertraline may depend on the baseline cholesterol concentration.

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.

Cholesterol, CSF 5-HIAA, violence and intent in suicidal men

Associations between suicide, violent behaviour and both hypocholesterolaemia and low 5-hydroxyindolacetic acid (5-HIAA) in the cerebrospinal fluid (CSF) have been suggested. The relationships between lipids, the serotonergic system, suicidal and aggressive behaviors are complex. We explored relationships between serum cholesterol, CSF 5-HIAA, the planning subscale of suicide intent and violence of attempted suicide method in 13 medication-free male suicide attempters and eight healthy volunteers. Serum high-density lipoprotein cholesterol (HDL-C) levels were significantly lower in suicide attempters than in controls. HDL-C showed a significant positive correlation with the planning subscale of suicide intent in non-violent suicide attempters. A positive association was observed between CSF 5-HIAA and serum cholesterol in suicides. The role of cholesterol may be different in planned non-violent suicide attempts compared with violent suicide attempts.

Serum leptin and cholesterol values in violent and non-violent suicide attempters

Earlier studies have linked lipid metabolism to suicide and impulsive-aggressive behaviors. We previously reported that suicide attempters had significantly lower leptin and cholesterol levels than controls. Since lower cholesterol levels have been related to violence alone, we decided to evaluate serum total cholesterol and leptin levels in violent and non-violent suicide attempters. In the present study, 19 violent, 16 non-violent suicide attempters, and 20 age- and sex-matched healthy controls were compared for serum total cholesterol and leptin levels. Violent suicide attempters had significantly lower total cholesterol and leptin levels compared with those with non-violent suicide attempts. Our results suggest that low serum cholesterol and leptin levels are related to the following two dimensions of suicide attempts: suicidality and violence.

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.

Urbanicity and methods of suicide: a nationwide population-based study

Despite urban-rural disparities in suicide rates having been reported in prior studies, there is scant information on the impact of urbanicity on suicide methods. This study investigates violent and nonviolent suicide methods in Taiwan and their association with urbanicity. We use a Taiwanese nationwide mortality database covering the period January 1997 to December 2003. A multilevel logistic regression analysis was performed to examine the relationship between urbanicity and violent/nonviolent suicide methods after adjusting for the age, gender, marital status and employment status of the victims, and the seasons during which the deaths occurred to account for possible dependence within cities/towns. Of the total of 17,849 suicide deaths examined, those residing in more urbanized areas tended to commit suicide by violent methods, an association that remains after controlling for the age, gender, marital and employment status of the victims, and the season during which the deaths occurred. We concluded that a significant association is noted between urbanicity and suicide methods. Thus, effective strategies for suicide prevention should also consider urbanicity.

Mood symptoms and serum lipids in acute phase of bipolar disorder in Taiwan

Serum lipids have been found to play important roles in the pathophysiology of mood disorders. The aim of the present study was therefore to investigate the relationship between symptom dimensions and serum cholesterol and triglyceride levels, and to explore correlates of lipid levels during acute mood episodes of bipolar I disorder in Taiwan. Measurements were taken of the serum cholesterol and triglyceride levels in patients with bipolar I disorder hospitalized for acute mood episodes (68 manic, eight depressive, and six mixed). The relationships between serum lipids levels and various clinical variables were examined. The mean serum levels of cholesterol (4.54 mmol/L) and triglycerides (1.16 mmol/L) of sampled patients were comparable to those of the general population in the same age segment. Severe depressive symptoms and comorbid atopic diseases were associated with higher serum cholesterol levels. A negative association was noted between serum triglyceride levels and overall psychiatric symptoms. Compared with previous studies on Western populations, racial differences may exist in lipids profiles of bipolar disorder patients during acute mood episodes. Increased serum cholesterol levels may have greater relevance to immunomodulatory system and depressive symptoms, in comparison with manic symptoms.

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.

Serum lipid levels in seasonal affective disorder

Previous research has assessed the relationship between blood lipid levels and depression with contradictory results. Several studies have linked low cholesterol levels with impulsive, aggressive and suicidal behaviours. The aim of this pilot study was to examine serum lipids in a sample of patients suffering from seasonal affective disorder (SAD). We conducted a retrospective analysis of data on total serum cholesterol and serum triglycerides in 39 SAD patients and 40 non-seasonally depressed or schizophrenic control subjects. Study subjects had to be free of psychotropic drugs for at least 2 weeks. Analysis of covariance (ANCOVA) was performed to assess group differences. After adjustment for significant covariates SAD patients had significantly lower total cholesterol levels (5.21 +/- 1.14 mmol/l) than control subjects (5.94 +/- 1.11 mmol/l; p = 0.013). Moreover, hypercholesterolemia (total cholesterol > 5.20 mmol/l) was significantly less frequent in the SAD group (46.2%) than in the control group (75.0%; p = 0.012). Total serum triglycerides did not differ significantly between SAD patients (1.54 +/- 1.07 mmol/l) and controls (1.56 +/- 0.96 mmol/l; p = 0.126). The results of this study support the idea that low cholesterol levels may be of pathogenetic importance in SAD. Further study in larger clinical samples is warranted to clarify our findings.

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.

Low plasma BDNF is associated with suicidal behavior in major depression

Brain-derived neurotrophic factor (BDNF), the most abundant neurotrophin in the brain, has a known association with the pathophysiology of anxiety and depression. However, the role of BDNF in suicide has not been well investigated to date. This study examined plasma BDNF levels in 32 major depressive disorder (MDD) patients who had recently attempted suicide, 32 non-suicidal MDD patients, and 30 normal controls. The lethality of the suicide attempt was measured using the Risk-Rescue Rating (RRR) and Lethality Suicide Attempt Rating Scale (LSARS). The severity of depression was measured with the Hamilton Depression Rating Scale (HDRS). Plasma BDNF levels were measured by enzyme linked immunosorbent assay. BDNF levels were significantly lower in suicidal MDD patients (430.5+/-397.0 pg/ml) than non-suicidal MDD patients (875.80+/-663.02 pg/ml) or normal controls (889.4+/-611.3 pg/ml) (F=6.682, p=0.002). The most suitable cut-off point of BDNF level between suicidal depression and non-suicidal depression groups was 444.58 pg/ml. At this cut-off point, the sensitivity=68.7%, specificity=78.1%, positive predictive value=75.9%, and negative predictive value=71.4%. However, there was no significant difference in BDNF levels between the depressive control and normal control groups (p=0.996). LSARS and RRR did not reveal any significant correlations with BDNF levels in suicidal patients. In addition, BDNF levels were not different between fatal and non-fatal suicide attempts. These results suggest that reduction of plasma BDNF level is related to suicidal behavior in major depression and that BDNF level may be a biological marker of suicidal depression.

Serum ghrelin and cholesterol values in suicide attempters

In our previous study, we demonstrated that suicide attempters had statistically significant lower leptin and cholesterol levels compared with healthy controls. In keeping with our previous report regarding lower serum cholesterol and leptin levels in suicide attempters compared with healthy controls, the relationship between cholesterol and leptin, and ghrelin, we aimed to evaluate serum total cholesterol and ghrelin levels in suicide attempters. In the present study, 30 patients with suicide attempts (aged 18-47 years) and the same number of healthy controls were compared with regard to serum total cholesterol and ghrelin levels. The mean cholesterol level of the patients was significantly lower than that of the controls. On the other hand, the suicide attempters had significantly higher ghrelin levels compared with the controls. The results suggest that suicide attempts seem to be associated with decreased serum cholesterol and higher ghrelin values.

Soluble interleukin 2 receptor levels, temperament and character in formerly depressed suicide attempters compared with normal controls

An imbalance of the immune system and mixed personality profiles in suicide attempters have been reported. As suicidal behavior is common in patients with psychiatric disorders within the spectrum of depressive features, in this study we measured soluble interleukin-2 receptor concentrations in plasma (sIL-2R) and investigated temperament and character profile and their potential correlation in formerly depressed patients with a history of suicide attempt. We studied sIL-2R levels in plasma and personality characteristics (using Cloninger's Temperament and Character Inventory [TCI]) of formerly depressed patients who had attempted suicide a mean of 3 years previously (n = 25), and age and gender matched normal controls (n = 25). There was no significant difference in sIL-2R levels between formerly depressed suicide attempters and age and gender matched normal controls (0.23 ng/ml +/- 0.25 vs. 0.19 ng/ml +/- 0.16). When compared to normal controls, suicide attempt patients had a significantly higher score on the temperament dimension "harm avoidance" and a lower score on the character dimension "self-directedness." No significant correlation was found between sIL-2R values and TCI dimensions. We propose that the liability to suicidal behavior among suicide attempters susceptible to depressive symptomatology may be related to high harm avoidance and low self-directedness.

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.

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.

Biosocial bases of aggressive and violent behavior—implications for nursing studies

Although aggression and violence have been increasingly viewed as a major public health problem with a biological and health basis, it has been under-researched in the nursing and health context. This paper reviews early biological risk factors for violence. These factors include pregnancy/birth complications, fetal exposure to nicotine, alcohol, and drugs, low cholesterol, malnutrition, lead and manganese exposure, head injuries and brain dysfunction, low arousal, low serotonin, low cortisol, and high testosterone. A biopsychosocial violence mode is proposed. Finally, the paper argues that nursing is ideally placed to develop a new body of knowledge based on a biosocial perspective that can lead to more effective prevention programs for violence.

High CSF-insulin in violent suicide attempters

Several studies have investigated a connection between diabetes and major depressive disorder (MDD). Whether these associations are mediated by changes in insulin is not known. Insulin seems to play a role in violent behaviour. To further elucidate the role of insulin in MDD and violent, aggressive, or impulsive behaviour, we measured insulin in cerebrospinal fluid (CSF) in 74 patients with a recent suicide attempt. Patients were divided into those with and without MDD, and they were also subgrouped by whether the suicide attempt was considered to be violent or not. It was found that patients with a violent suicide attempt had significantly higher CSF-insulin (5.9+/-1.0 pmol/l) than those with a nonviolent attempt (5.3+/-0.7 pmol/l). In contrast, there were no significant differences in CSF-insulin between patients with MDD and patients without. Our findings support the hypothesis that CSF-insulin is involved in violent behaviour, but not connected to MDD as such.

Low CSF leptin in female suicide attempters with major depression

BACKGROUND

Leptin is a hormone known to participate in the regulation of weight and appetite and is therefore of interest to examine in the context of major depressive disorder (MDD). Studies of circulating leptin have yielded variable results. We therefore decided to study leptin in cerebrospinal fluid (CSF).

METHODS

We measured leptin in cerebrospinal fluid (CSF) in 72 patients admitted after a suicide attempt. They were divided in two groups: patients with major depressive disorder (MDD) and patients with other diagnoses (non-MDD). They were also subgrouped according to the number of suicide attempts (one or repeated) and whether the suicide attempt method was classified as violent or nonviolent. Since CSF leptin was considerably lower in men than in women, statistical calculations were made for men and women separately.

RESULTS

We found that in spite of having similar body mass index (BMI) (P = 0.1), women in the MDD group had lower CSF leptin than those in the non-MDD group (P < 0.01). In contrast, no such difference was found among men. No significant differences were found between women with a first suicide attempt compared to those with a repeated one, or between women with a violent attempt compared to those with a nonviolent attempt.

LIMITATIONS

The heterogeneity of the non-MDD group including patients with various diagnoses is the most important limitation of our study.

CONCLUSIONS

CSF leptin is involved in the neuroendocrine dysfunction in women with suicide attempt and MDD. This finding contributes to the understanding of the metabolic symptoms in MDD.

Serum lipid concentrations in Croatian veterans with post-traumatic stress disorder,post-traumatic stress disorder comorbid with major depressive disorder,or major depressive disorder

The aim of this study was to assess eventual differences in serum cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides, LDL-C/HDL-C ratio between veterans with combat-related post-traumatic stress disorder (PTSD) only or comorbid with major depressive disorder (MDD), veterans with combat experiences with MDD, and healthy control group. PTSD and/ or MDD were diagnose according to structured clinical interview based on DSM-IV criteria. Additional criteria to diagnose PTSD were Clinician Administered PTSD Scale (CAPS), and to diagnose MDD Montgomery-Asberg Depression Rating Scale (MADRAS). Serum lipid concentrations were determined by using the enzyme-assay method. Veterans with combat-related PTSD as well as veterans with combat-related PTSD comorbid with MDD showed significantly higher concentrations of cholesterol (F=9.858, p<0.01), triglycerides (F=10.112, p<0.01), LDL-C (F=11.145, p<0.01), and LDL-C/HDL-C ratio (F=8.346, p<0.01) vs. veterans with MDD or healthy control group. Contrary healthy control group and veterans with MDD showed significantly higher concentrations of HDL-C (F=8.421, p<0.01), vs. veterans with PTSD or PTSD comorbid with MDD. In conclusion, there are no differences in serum lipid concentrations between veterans with combat-related PTSD and PTSD comorbid with MDD, but they have higher lipid concentrations than veterans with MDD or healthy control subjects.

Cholesterol in mood and anxiety disorders: review of the literature and new hypotheses

Cholesterol plays an integral role in the structure and function of the cell membrane and may also affect neurotransmission in the central nervous system. Previous work has identified abnormalities in serum cholesterol levels in patients with mood and anxiety disorders as well as in suicidal patients. However, the biological significance of these abnormalities remains to be clarified. An understanding of how serum cholesterol relates to the pathophysiology of mood disorders may generate biological markers that predict treatment response as well as targets for novel therapeutic strategies. In this article, we review the literature studying the significance of cholesterol in mood and anxiety disorders, with an emphasis on new studies focusing on the adverse impact of hypercholesterolemia on the treatment of major depressive disorder (MDD). We then propose possible mechanisms that would account for the relationship between elevated cholesterol and treatment non-response in MDD.

No evidence for an association between serum cholesterol and the course of depression and suicidality

In a number of previous reports, an association of altered, in most cases lower, serum cholesterol levels with depression, suicidal ideation and current or past suicidal behavior has been suggested. In this investigation, the course of serum cholesterol concentrations was measured in depressed patients during treatment. Ninety-two inpatients with a major depressive episode were included. Serum lipid concentrations were assessed at admission, after 1 week and after 4 weeks of antidepressant treatment. Degrees of depression and suicidality were measured with the Hamilton Depression Rating Scale. Although there was a significant reduction in depression and suicidality scores, neither a significant change in serum cholesterol levels nor a correlation between cholesterol levels and clinical improvement was found. Further, there were no significant differences in lipid levels between patients with and without a history of attempted suicide. In patients who had used a violent method, there was a trend for lower total cholesterol levels compared to those who had poisoned themselves. The results of this study do not support the hypothesis of an association of serum cholesterol with the course of depression and suicidal ideation. Cholesterol levels do not appear to be an appropriate biological marker for suicidality during the first 4 weeks of treatment in patients with a major depressive episode.

Weather and suicide: the present state of knowledge on the association of meteorological factors with suicidal behaviour

OBJECTIVE

To review the available literature on the association between daily and longer-term weather data and the incidence of attempted and completed suicide.

METHOD

A computerized search supplemented by a cross-check of the references sections of the thereby identified papers was performed.

RESULTS

A total of 27 studies looking for a relationship between attempted or completed suicide and weather or climate data were found. Most of the papers reported a statistical association of suicidal acts with at least one weather factor. However, the results are not conclusive and in part contradictory.

CONCLUSION

Possibly due to the high variance in methodological approaches of the studies it is not possible to identify a specific weather condition associated with a generally higher risk for suicide. Weather and seasonal effects may interact with each other. Environmental effects on brain function and weather-related interactions of people may be involved in the occurrence of suicidal behaviour.

Serum lipid levels and suicide attempts

OBJECTIVE

To determine whether a correlation exists between lower serum lipid concentrations and increased suicide risk.

METHOD

Serum lipid profiles were pair-matched for 60 patients who had recently experienced failed attempts at suicide and equal numbers of non-suicidal psychiatric patients, and normal controls. Suicide attempt severity was scored using Weisman and Worden's risk-rescue rating scale.

RESULTS

(a). Total serum cholesterol and low density lipoprotein levels were found to be lower in the parasuicidal population at statistically significant levels (P < 0.01 and <0.05, respectively); (b). triglyceride concentrations were lower in suicide attempters with major depression compared with non-suicidal depressed patients; and (c). risk-rescue rating scores were negatively correlated with total serum cholesterol levels (r = -0.347, P = 0.007).

CONCLUSION

Low lipid metabolism may be a potential biological marker in the assessment of suicide risk. Further investigations are necessary to elucidate the biological mechanisms of these findings.

Serum leptin and cholesterol levels in schizophrenic patients with and without suicide attempts

OBJECTIVE

Previous studies demonstrate a relationship between lipid metabolism and suicide or impulsive-aggressive behaviours. Leptin seems to be related with lipid metabolism. Therefore, the aim was to measure total serum cholesterol and leptin levels in 16 medication-free schizophrenic patients with and without suicide attempts and in 16 healthy controls.

METHOD

Subjects were assessed by using Impulsivity Rating (IRS) and Modified Overt Aggression Scale (MOAS).

RESULTS

The patients had lower total cholesterol and leptin levels in serum compared with the controls. Significantly lower total cholesterol and leptin levels were observed in patients who had attempted suicide compared with those who had not. The levels were observed to be low in violent attempters when compared with non-violent attempters. MOAS and IRS scores were negatively correlated with both cholesterol or leptin levels in patients.

CONCLUSION

The results indicated that medication-free schizophrenic patients have statistically significant lower serum cholesterol and leptin levels compared with controls and the difference is obvious in suicide attempters compared with non-suicide attempters and in violent attempters than non-violent attempters.