Total cholesterol and suicidality in depression

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.

Serum Lipid Levels and Suicide Attempts Within 2 Weeks in Patients With Major Depressive Disorder: Is There a Relationship?

The potential correlation between serum lipid profiles and suicidal tendencies has been previously reported, however, it is unclear whether serum lipid profiles have definite relevance to recently attempted suicides in individuals suffering from major depressive disorder (MDD). In this study, the relationship between blood lipids and suicide attempts in first-episode MDD patients in research were used to examine whether there is a connection. The cross-sectional study recruited 580 patients at the time of their first episode, measuring up to the diagnostic standard of MDD. Baseline demographic, clinical data, and blood lipid level data were collected. Depression severity was measured with the Hamilton Depression Rating Scale (HAMD). Our results revealed that the level of TC may be identified as a promising and effective biomarker for first-episode MDD suicide risk, suggesting that screening of serum lipid profiles in depressive patients is essential for suicide prevention.

Association between serum lipid concentrations and attempted suicide in patients with major depressive disorder: A meta-analysis

Background

There is growing evidence that serum lipid concentrations may be associated with attempted suicide in patients with major depressive disorder (MDD), but these findings remain controversial. Thus, we performed a comprehensive meta-analysis to quantitatively assess the associations between serum lipid concentrations and attempted suicide in MDD patients.

Materials and methods

Electronic databases (PubMed, Embase, the Cochrane Library and the China National Knowledge Library) were searched for relevant literature up to 10 February 2020. We used a random-effects model based on heterogeneity amongst studies and generated pooled standardised mean differences (SMDs).

Results

Thirty-two studies comprising 7,068 subjects met the inclusion criteria. A pooled analysis showed that compared with non-attempters, MDD patients who had attempted suicide had significantly lower serum concentrations of total cholesterol (TC) (SMD: -0.63, 95% CI: -0.83 to -0.44) and low-density lipoprotein cholesterol (LDL-C) (SMD: -0.69, 95% CI: -1.04 to -0.34), but the serum concentrations of high-density lipoprotein cholesterol (HDL-C) (SMD: -0.12, 95% CI: -0.33 to 0.10) and triglycerides (TGs) (SMD: 0.00, 95% CI: -0.20 to 0.20) were not significantly different between the two groups. Subgroup and meta-regression analysis indicated that heterogeneity with respect to TC concentrations may be due to different ages (p = 0.041) and sample sizes (p = 0.016) of studies, and that heterogeneity with respect to HDL-C concentrations may be partly due to different settings of studies (p = 0.017).

Conclusions

This meta-analysis demonstrated that lower concentrations of TC and LDL-C, but not of HDL-C and TGs, were associated with attempted suicide in MDD patients. This indicates that TC and LDL-C may be useful as biological markers for predicting whether MDD patients may attempt to commit suicide.

Searching for a predictive peripherical biological model in parasuicidal behaviour

The aim of this study was to identify possible peripheral biological markers (both lipidic and hormonal) which can be easily used for the early detection of parasuicidal behaviour and to propose a predictive biological model of such behaviour. A case-control analytical study was undertaken at least 3 months after attempted suicide. Study was made of 128 patients who presented at the University General Hospital of Oviedo (Spain) with signs of self-intoxication. Lipidic and hormonal profiles were measured under basal conditions and comparison was made with a control group of healthy volunteer donors obtained from the Oviedo General Hospital blood bank. A discriminant analysis was later made with the aim of establishing a predictive biological model. This included the following variables: cholesterol, HDL-C, LDL-C and cortisol. Sensitivity and specificity were 62.5% and 65.6%, respectively. Replication and improvement of this model, through other prospective studies, could lead to the use of serum cholesterol and cortisol levels as inexpensive and readily available markers of suicide risk.

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.

The Association between Depressive Mood and Cholesterol Levels in Korean Adolescents

OBJECTIVE

Previous studies have shown that there is a correlation between lipid levels and depressive mood, and that lipids could be useful biomarkers for depression. We conducted this study to clarify the association between lipid levels and depressive mood in adolescents, especially in community samples.

METHODS

We analyzed data from the Korea National Health and Nutrition Examination Survey (KNHANES) that was conducted from 2013 to 2016. A total of 2,454 adolescents aged 12-18 years (1,273 boys, 1,181 girls) participated in the Survey. We conducted a cross-sectional study using multiple logistic regression, adjusting for age, household income, daily energy intake, daily fat intake, and daily cholesterol intake, to assess the association between depressive mood and serum lipid levels.

RESULTS

Depressive mood was found in 8.7% of those included in the study. Borderline (110-129 mg/dL) and high (≥130 mg/dL) levels of low-density lipoprotein cholesterol (LDL-C) were significantly associated with depressive mood [Borderline level: odds ratio (OR)=5.55, 95% confidence interval (CI) 1.56-19.81, p=0.01; High level: OR=5.73, 95% CI 1.06-31.08, p=0.04]. However, this association was not found in girls.

CONCLUSION

Our findings indicate that depressive mood in boys is associated with higher LDL-C levels. Further investigation regarding this relationship and the underlying biological mechanisms is needed.

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.

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.

Lipids, aggression, suicidality and impulsivity in drug-naïve/drug-free patients of schizophrenia

AIM

Present study aimed at determining lipid profiles in acutely symptomatic drug-naïve/drug-free patients of schizophrenia, comparing them with healthy controls and exploring relationships between various lipid fractions, aggression, suicidality and impulsivity in this population.

MATERIALS AND METHODS

This was a cross-sectional hospital-based study, comparing patients with schizophrenia (M=46, F=14; mean age 32.40±6.6 years; 48 drug-free for 10.50±9.2 weeks) with 60 age-sex matched healthy controls. Upon recruitment, fasting venous blood samples of all subjects were analysed for total cholesterol, HDL, LDL, VLDL and TG levels, and patients were rated on PANSS for symptom severity, Modified Overt Aggression Scale for aggression, Impulsivity Rating Scale for impulsivity and Scale for Suicide Ideation for suicidality.

RESULTS

The socio-demographic characteristics of the patients were comparable to controls. In patients, total cholesterol, HDL and LDL levels were found to be significantly lower (p<0.01) than the control group. When explored further in patients, lower total cholesterol and LDL levels showed significant negative correlations with scores on impulsivity (p<0.01) and suicidality (p<0.05); and TG level showed a negative correlation with impulsivity (p<0.05).

CONCLUSIONS

This study adds to a growing literature on a complex relationship between lipid fractions and impulsivity, suicidality and aggression in schizophrenia; providing interesting insights into the biochemical basis of human behaviour and confirming these in a developing-world population. The implications are many, including a need to review judiciously the promotion of weight loss and cholesterol reduction programmes in constitutionally vulnerable population, at least during their acutely-symptomatic states.

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.

Is low total cholesterol levels associated with suicide attempt in depressive patients?

BACKGROUND

Patients with major depressive disorder (MDD) have a high risk of suicide. Many pathophysiological factors involved in MDD and suicide such us a low cholesterol levels have been associated with MDD and increased vulnerability to suicide. In this study, we investigate the relation between lipid parameters and suicide risk in patients with MDD.

METHODS

Plasma levels of total cholesterol, triglycerides, and high-density lipoprotein cholesterol (HDL-c) and low-density lipoprotein cholesterol (LDL-c) were determined in 160 patients meeting the DSM-IV-TR criteria for MDD (110 patients without suicidal behavior and 52 suicidal attempters) and 151 healthy controls.

RESULTS

A significant decrease in plasma cholesterol levels was observed in the group of suicidal depressive patients compared to those without suicidal behavior (p < 0.001). For the other lipid levels (triglycerides, HDL cholesterol, and LDL cholesterol), there were no significant differences between suicidal and non-suicidal patients.

CONCLUSIONS

Our study showed a significant decrease in plasma cholesterol levels in suicidal patients. This result support the hypothesis of the association of low plasma cholesterol level and suicidal behavior in patients with major depressive disorder.

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.

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.

Female attempted suicide patients with low HDL levels are at higher risk of suicide re-attempt within the subsequent year: a clinical cohort study

Our aims were, to clarify the blood lipid differences [Total serum cholesterol (TC), High-density lipoprotein (HDL), Low density lipoprotein (LDL), Triglyceride (TG)] between female patients who had attempted suicide and controls and to determine whether we could use the patients׳ initial lipid profiles to predict suicide re-attempt within the subsequent year. A total of 284 participants (110 cases and 174 controls) were recruited, with no differences in body mass index, age, blood sampling time and gender. Blood samples were collected from all participants for serum lipid profiles and assayed in an auto-analyzer. We divided the suicide re-attempter group into suicide attempters in the subsequent year (SSY) and suicide attempters after the subsequent year (SASY). The TC, LDL, and TG levels were significantly lower in the suicidal group than in the control group. HDL was significantly higher in the suicidal group than in the control group. Low TG (<70mg/dL) (OR (odds ratio)=12.8; 95% CI (confidence interval)=5.4-30.5; p<0.0001)and low LDL/HDL (<1.8) (OR=4.1; 95% CI=1.8-9.3; p=0.001) were significantly associated with a current suicide attempt. HDL levels in the SSY (41.5±4.5mg/dL) were lower than in the non-suicide attempters group (NSA) (50.9±10.3mg/dL) and SASY (58.7±12.8mg/dL)(d.f.=2, F=5.2, p=0.007). Serum HDL level may be a potential candidate predictor for the future risk of suicidality.

Evidence for the role of EPHX2 gene variants in anorexia nervosa

Anorexia nervosa (AN) and related eating disorders are complex, multifactorial neuropsychiatric conditions with likely rare and common genetic and environmental determinants. To identify genetic variants associated with AN, we pursued a series of sequencing and genotyping studies focusing on the coding regions and upstream sequence of 152 candidate genes in a total of 1205 AN cases and 1948 controls. We identified individual variant associations in the Estrogen Receptor-ß (ESR2) gene, as well as a set of rare and common variants in the Epoxide Hydrolase 2 (EPHX2) gene, in an initial sequencing study of 261 early-onset severe AN cases and 73 controls (P=0.0004). The association of EPHX2 variants was further delineated in: (1) a pooling-based replication study involving an additional 500 AN patients and 500 controls (replication set P=0.00000016); (2) single-locus studies in a cohort of 386 previously genotyped broadly defined AN cases and 295 female population controls from the Bogalusa Heart Study (BHS) and a cohort of 58 individuals with self-reported eating disturbances and 851 controls (combined smallest single locus P<0.01). As EPHX2 is known to influence cholesterol metabolism, and AN is often associated with elevated cholesterol levels, we also investigated the association of EPHX2 variants and longitudinal body mass index (BMI) and cholesterol in BHS female and male subjects (N=229) and found evidence for a modifying effect of a subset of variants on the relationship between cholesterol and BMI (P<0.01). These findings suggest a novel association of gene variants within EPHX2 to susceptibility to AN and provide a foundation for future study of this important yet poorly understood condition.

The relationship between impulsivity and lipid levels in bipolar patients: does temperament explain it?

BACKGROUND

The aim of this study was to investigate whether there was a relationship between impulsivity and lipid levels in patients with bipolar disorder (BD) and to examine the correlation of impulsivity and lipid levels with temperament subtypes.

METHODS

For this purpose, one hundred patients who were admitted to our out-patient unit for routine controls, had been in remission for at least 8weeks, and diagnosed as BD according to the DSM-IV were evaluated consecutively. Impulsivity and temperament were evaluated with the BIS-11 and the TEMPS-A. Blood samples were obtained to measure levels of lipids (cholesterol, triglyceride, high density lipoprotein-HDL, low density lipoprotein-LDL).

RESULTS

A weak correlation was found between impulsivity scores and triglyceride levels (r=0.190, p=0.050). Correlation was found between impulsivity scores and depressive, anxious, cyclothymic, and irritable temperaments (r=0.371, p<0.001; r=0.458, p<0.001; r=0.541, p<0.001; r=0.530, p<0.001), while triglyceride levels were only related with depressive and anxious temperaments (r=0.485, p=0.001 and r=0.391, p=0.006).

CONCLUSIONS

Temperament is an important mediator of the relationship between lipid levels and trait impulsivity in patients with BD.

Longitudinal associations between serum cholesterol levels and suicidal ideation in an older Korean population

INTRODUCTION

Relationships between low total cholesterol levels and suicidality have been reported but there has been little investigation of this issue in older age groups. This study aimed to investigate longitudinal associations between serum lipid levels and suicidal ideation in an older population.

METHODS

732 community dwelling elderly aged 65 or over were evaluated at baseline. Of 639 did not have suicidal ideation at baseline, 579 (90.6%) were followed two years later. Prevalence and incidence of suicidal ideation within the previous one month was ascertained. Serum levels of total-, high density lipoprotein (HDL)-, low density lipoprotein (LDL)- cholesterol, and triglycerides were assayed at both baseline and follow-up. Baseline data on potential covariates including sociodemographic characteristics, life stress, social support, pain, alcohol drinking, depressive symptoms, cognitive function, and disability were gathered.

RESULTS

Both higher and lower total and LDL cholesterol levels at baseline and a decline in total cholesterol levels over the follow-up period predicted an increased incidence of suicidal ideation at follow-up independent of sociodemographic and clinical covariates. Significant cross-sectional associations were found between suicidal ideation at baseline and higher total and LDL cholesterol levels.

LIMITATIONS

Suicidal ideation was the outcome of the study. Therefore generalizability should be considered.

CONCLUSIONS

These results support a role of dyslipidemia in the etiology of late-life suicidal ideation. Not only low but also higher cholesterol levels predicted the incidence of suicidal ideation in elders. Lipid sub-fraction assays might be informative in this respect at least in older populations.

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.

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.

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.

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.

Total serum cholesterol levels and suicide attempts in child and adolescent psychiatric inpatients

Associations between cholesterol and suicidal behavior in adolescent patients have not been explored in depth. In this study, 66 patients consecutively admitted to a psychiatric inpatient unit following attempted suicide were compared with a control group of 54 patients with no history of suicide attempts. The age range of the sample was from 8 to 18 years old. Cholesterol levels were significantly lower in attempted suicide patients than in controls (p < 0.02), supporting the hypothesis that lower cholesterol levels might be associated with suicidal behavior in patients with similar acute phase of their disorder.

The relationship between depression, anxiety, and cardiovascular outcomes in patients with acute coronary syndromes

Depression and anxiety occur at high rates among patients suffering an acute coronary syndrome (ACS). Both depressive symptoms and anxiety appear to adversely affect in-hospital and long term cardiac outcomes of post-ACS patients, independent of traditional risk factors. Despite their high prevalence and serious impact, mood and anxiety symptoms go unrecognized and untreated in most ACS patients and such symptoms (rather than being transient reactions to ACS) persist for months and beyond. The mechanisms by which depression and anxiety are linked to these negative medical outcomes are likely a combination of the effects of these conditions on inflammation, catecholamines, heart rate variability, and endothelial function, along with effects on health-promoting behavior. Fortunately, standard treatments for these disorders appear to be safe, well-tolerated and efficacious in this population; indeed, selective serotonin reuptake inhibitors may actually improve cardiac outcomes. Future research goals include gaining a better understanding of the combined effects of depression and anxiety, as well as definitive prospective studies of the impact of treatment on cardiac outcomes. Clinically, protocols that allow for efficient and systematic screening, evaluation, and treatment for depression and anxiety in cardiac patients are critical to help patients avoid the devastating effects of these illnesses on quality of life and cardiac health.

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.

Neuropsychiatric consequences of cardiovascular medications

The use of cardiovascular medications can have a variety of neuropsychiatric consequences. Many cardiovascular agents cause higher rates of fatigue and sedation than placebo, and case reports of medication-induced mood syndromes, psychosis, and cognitive disturbances exist for many cardiovascular drugs. Depression has been associated with β-blockers, methyldopa, and reserpine, but more recent syntheses of the data have suggested that these associations are much weaker than originally believed. Though low cholesterol levels have been associated with depression and suicide, lipid-lowering agents have not been associated with these adverse effects. Finally, cardiovascular medications may have beneficial neuropsychiatric consequences; for example, the use of clonidine in patients with attention deficit-hyperactivity disorder, the use of prazosin for patients with post-traumatic stress disorder, and the use of propranolol for performance anxiety and akathisia.

Increased plasma nitric oxide metabolites in suicide attempters

OBJECTIVE

To evaluate any correlation between plasma levels of nitric oxide metabolites (NO(x)) and suicide attempt.

METHOD

Plasma NO(x) levels were measured in 53 patients who had recently attempted suicide, 58 non-suicidal psychiatric patients, and 75 normal controls. The severity of suicidal behaviors was evaluated using Weisman and Worden's Risk-Rescue Rating Scale.

RESULTS

Plasma NO(x) levels were significantly higher in suicidal patients than non-suicidal psychiatric patients or normal control subjects (F=11.029, d.f.=2, 183, p<0.001). Among the patients with a diagnosis of major depression, suicidal depressive patients had significantly higher plasma NO(x) levels than non-suicidal depressive patients (t=-3.090, d.f.=84, p=0.003).

CONCLUSION

Our study suggests that increased NO production in plasma is associated with suicide attempt, especially in depressive patients.

Low HDL cholesterol is associated with suicide attempt among young healthy women: the Third National Health and Nutrition Examination Survey

BACKGROUND

Serum cholesterol is reported to be associated with suicidality, but studies conducted among general healthy population are rare. We examined the association between serum cholesterol and suicidality in a national sample of the general population of US.

METHODS

We used the data of 3237 adults aged 17 to 39 years, who completed a mental disorder diagnostic interview and had blood specimens collected after a 12-h fast, as a part of the Third National Health and Nutrition Examination Survey, 1988-1994. The serum concentrations of total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were dichotomized according to the recommended levels of the National Cholesterol Education Program. A polytomous logistic regression was employed to control for covariates.

RESULTS

Independent of socio-demographic variables, health risks and nutrition status, and a history of medical and psychiatric illness (including depression), a significant association between low HDL-C (< or = 40 mg/dl) and increased prevalence of suicide attempts was observed in women (OR=2.93, 95% CI=1.07-8.00). No significant evidence was found to support an association between cholesterol and suicide ideation in women. Serum cholesterol was unrelated with either suicide ideation or attempts in men.

LIMITATION

The inherent limitation of cross-sectional design prevented the authors from investigating causality.

CONCLUSIONS

Low HDL-C is significantly associated with suicide attempts in women. Further studies are necessary to explore the clinical application of serum cholesterol as an indicator for suicide attempts among high risk population.

Lipid and lipoprotein levels in depressive disorders with melancholic feature or atypical feature and dysthymia

The purpose of the present study was to explore the relationship between serum lipid and lipoprotein levels and clinical subtypes in patients with depressive disorders. A total of 207 patients who were admitted for general health screening were assessed by using the semistructured clinical interview for Diagnostic and Statistical Manual of Mental Disorders (4th edn; DSM-IV) criteria for the possibility of having depressive disorders. Blood and physical examinations were done to rule out systemic diseases. A total of 142 patients without systemic diseases was recruited for further analysis, including dysthymia (n = 35), major depressive disorder with melancholic feature (n = 22), major depressive disorder with atypical feature (n = 46) and normal controls (n = 39). Analysis of covariance after age adjustment reveals significant differences in patients with melancholic feature and patients with atypical feature in serum concentrations of triglyceride (TG) and very-low-density-lipoprotein cholesterol (VLDL) in men, and high-density-lipoprotein cholesterol (HDL) in women. This suggests that the TG, VLDL and HDL levels might be used as biological markers to differentiate between major depressive patients with melancholic feature or atypical feature.

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.

Conceptual foundations of the UCSD Statin Study: a randomized controlled trial assessing the impact of statins on cognition, behavior, and biochemistry

BACKGROUND

Statin cholesterol-lowering drugs are among the most prescribed drugs in the United States. Their cardiac benefits are substantial and well supported. However, there has been persistent controversy regarding possible favorable or adverse effects of statins or of cholesterol reduction on cognition, mood, and behavior (including aggressive or violent behavior).

METHODS

The literature pertaining to the relationship of cholesterol or statins to several noncardiac domains was reviewed, including the link between statins (or cholesterol) and cognition, aggression, and serotonin.

RESULTS

There are reasons to think both favorable and adverse effects of statins and low cholesterol on cognition may pertain; the balance of these factors requires further elucidation. A substantial body of literature links low cholesterol level to aggressive behavior; statin randomized trials have not supported a connection, but they have not been designed to address this issue. A limited number of reports suggest a connection between reduced cholesterol level and reduced serotonin level, but more information is needed with serotonin measures that are practical for clinical use. Whether lipophilic and hydrophilic statins differ in their impact should be assessed.

CONCLUSION

There is a strong need for randomized controlled trial data to more clearly establish the impact of hydrophilic and lipophilic statins on cognition, aggression, and serotonin, as well as on other measures relevant to risks and quality-of-life impact in noncardiac domains.

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.

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 cholesterol levels and suicide: a meta-analysis

A meta-analysis was performed on studies exploring the link between low levels of serum cholesterol and increased risk of suicide. Follow-up studies found that those with lower cholesterol levels do have a tiny but statistically significant increased risk of completing suicide. Individuals who have attempted suicide in the past have lower cholesterol levels, especially if they used violent methods for suicide. Cholesterol lowering studies, however, did not lead to a significant increase in completed suicide.

Cholesterol concentrations in violent and non-violent women suicide attempters

The aim of this study was to evaluate whether women with a history of violent suicide attempts have lower serum cholesterol concentrations than those who attempted suicide by non-violent methods. Our retrospective study used a case-control design to compare serum total cholesterol concentration, hematocrit, red blood cell count and body mass index (BMI) in women with a history of violent (n = 19) or non-violent (n = 51) suicide attempts and of non-suicidal controls (n = 70) matched by diagnosis and age. Analysis of covariance (ANCOVA) with age as the covariate was used to analyze differences in cholesterol levels in groups according to violence. Violence was found to be a significant factor (P = 0.016). Using the Scheffé test, a significant difference (P = 0.011) was revealed between the group of violent and non-violent suicide attempters and between the violent suicide attempters and the control group. Patients with a violent suicidal attempt have significantly lower cholesterol levels than patients with non-violent attempts and the control subjects. Our findings suggest that suicide attempts should not be considered a homogeneous group. They are consistent with the theory that low levels of cholesterol are associated with increased tendency for impulsive behavior and aggression and contribute to a more violent pattern of suicidal behavior.

Association between low plasma levels of cholesterol and relapse in cocaine addicts

OBJECTIVE

In light of recent studies suggesting the existence of associations between low concentrations of cholesterol and various psychiatric disorders, we decided to explore relationships between cholesterol levels and relapse rates in a group of cocaine addicts who had undergone inpatient detoxification.

METHODS

The total cholesterol levels of 38 non-opiate-dependent and non-alcohol-dependent cocaine addicts were determined while they were hospitalized. Drug use was subsequently assessed 3, 6, and 12 months after patients were discharged from the hospital.

RESULTS

Comparisons of the cholesterol levels (obtained during hospitalization) of relapsers and nonrelapsers by analyses of covariance with age and weight as covariates revealed significantly lower cholesterol values in patients who relapsed at 3 months (p =.046), 6 months (p =.030), and 12 months (p =.019) after discharge.

CONCLUSIONS

This study showed an association between a low total cholesterol level and relapse rates in detoxified cocaine addicts. Reasons for the predictive value of low cholesterol levels for relapse for up to 1 year after cholesterol measurements were made are unclear. These data are preliminary and in need of replication.

Low serum cholesterol is correlated to suicidality in a Korean sample

OBJECTIVE

The aim of this study was to examine further the association between low total serum cholesterol and suicidal behaviour.

METHOD

We measured the serum cholesterol levels in 231 patients admitted to an emergency room following a suicide attempt, in 231 age-,sex- and diagnosis-matched non-suicidal psychiatric controls, and in 231 age- and sex-matched normal controls. The suicide attempt patients were divided into five grades according to the degree of injury.

RESULTS

The mean total cholesterol level of the suicide attempt patients was significantly lower than that of the psychiatric and normal controls. When the suicide attempt patients and non-suicidal psychiatric controls were divided by diagnosis, this significant relationship held true for major depressive disorders and personality disorders, but not for schizophrenia and bipolar disorders. Cholesterol level and the severity of suicide attempt were inversely correlated.

CONCLUSION

The results suggest that cholesterol level may serve as a marker for suicide risk. Possible explanations are discussed.

The association of low serum cholesterol with depression and suicidal behaviours: new hypotheses for the missing link

Several observational studies indicate that reduction of serum cholesterol levels is related to an increase in violent deaths and suicide but the nature of this possible relationship remains unclear. Many confounding factors, e.g. poor health, depression and loss of appetite may play a role in the apparent relationship between serum cholesterol levels and suicide. Two separate phenomena should be considered: lowering total cholesterol and low total cholesterol. This review considers the evidence from epidemiological studies on serum cholesterol lowering and psychiatric disturbances. The available evidence does not seem to substantiate the view that large-scale intervention to reduce cholesterol concentrations could lead to more violent and aggressive behaviour, and generally greater unhappiness. In recent trials using statin treatment, there were slightly fewer deaths from accidents and suicide in the treated group compared with the placebo group. We believe that clinicians should not be deterred from prescribing cholesterol-lowering drugs, to reduce the risk of death from coronary heart disease, when they are indicated.

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

Many previous studies have suggested that low or lowered serum cholesterol levels may increase the risk of mortality not due to somatic disease: principally, suicide and violent death. Because violent death is rare, some studies have investigated afterwards the relation between cholesterol levels and either suicide attempts in psychiatric populations or violence in criminally violent populations. However, none of these studies have compared cholesterol levels in violent and non-violent suicide attempters. The blood of 25 consecutive drug-free patients following a violent suicide attempt and of 27 patients following a non-violent suicide attempt by drug overdose was drawn in the 24 h following admission. Patients with a diagnosis of alcohol abuse and with cholesterol-lowering therapy were excluded. Age, sex, body mass index, psychiatric diagnosis and the physical conditions of the suicide attempt were investigated. Thirty-two healthy subjects were used as a control group. There were no differences between the groups in age, frequency of psychiatric diagnoses or body mass index. There was more women in the group of non-violent suicide attempters than in that of violent suicide attempters (P<0.001). In analyses controlling for sex and age, the serum cholesterol concentration was 30% lower (F(2,82)=15.8; P<0.0001) in the group of violent suicide attempters (147+/-54 mg/dl) than in the group of non-violent suicide attempters (209+/-38 mg/dl) or control subjects (213+/-46 mg/dl). Our results showed that low serum cholesterol level is associated with the violence of the suicide attempt and not with the suicide attempt itself. Further investigations are necessary to determine the usefulness of this easily accessible parameter as a potential risk indicator for violent acts such as violent suicidal behavior in susceptible individuals.

Low cholesterol and violent crime

BACKGROUND

Community cohort studies and meta-analyses of randomized trials have shown a relation between low or lowered cholesterol and death by violence (homicide, suicide, accident); in primates, cholesterol reduction has been linked to increased behavioral acts of aggression (Kaplan J, Manuck S. The effects of fat and cholesterol on aggressive behaviour in monkeys. Psychosom. Med 1990;52:226-7; Kaplan J, Shively C, Fontenot D, Morgan T, Howell S, Manuck S et al. Demonstration of an association among dietary cholesterol, central serotonergic activity, and social behaviour in monkeys. Psychosom. Med 1994;56:479-84.). In this study we test for the first time whether cholesterol level is related to commission of violent crimes against others in a large community cohort.

METHODS

We merged one-time cholesterol measurements on 79,777 subjects enrolled in a health screening project in Varmland, Sweden with subsequent police records for arrests for violent crimes in men and women aged 24-70 at enrollment; and with information on covariates. We performed a nested case control comparison of cholesterol in violent criminals - defined as those with two or more crimes of violence against others - to cholesterol in nonoffenders matched on age, enrollment year, sex, education and alcohol, using variable-ratio matching, with a nonparametric sign test.

RESULTS

One hundred individuals met criteria for criminal violence. Low cholesterol (below the median) was strongly associated with criminal violence in unadjusted analysis (Men: risk ratio 1.94, P=0.002; all subjects risk ratio 2.32, P<0.001). Age emerged as a strong confounder. Adjusting for covariates using a matching procedure, violent criminals had significantly lower cholesterol than others identical in age, sex, alcohol indices and education, using a nonparametric sign test (P=0.012 all subjects; P=0.035 men).

CONCLUSIONS

Adjusting for other factors, low cholesterol is associated with increased subsequent criminal violence.

Low HDL cholesterol, aggression and altered central serotonergic activity

Many studies support a significant relation between low cholesterol levels and poor impulse, aggression and mood control. Evidence exists also for a causal link between low brain serotonin (5-HT) activity and these behaviors. Mechanisms linking cholesterol and hostile or self-destructive behavior are unknown, but it has been suggested that low cholesterol influences 5-HT function. This study was designed to explore the relationship between plasma cholesterol, measures of impulsivity and aggression, and indices of 5-HT function in personality disordered cocaine addicts. Thirty-eight hospitalized male patients (age 36.8+/-7.1) were assessed with the DSM-III-R, the Buss-Durkee Hostility Inventory (BDHI), the Barratt Impulsiveness Scale (BIS) and the Brown-Goodwin Assessment for Life History of Aggression. Fasting basal cholesterol (total, LDL and HDL) was determined 2 weeks after cocaine discontinuation. On the same day 5-HT function was assessed by neuroendocrine (cortisol and prolactin) and psychological (NIMH and 'high' self-rating scales) responses following meta-chlorophenylpiperazine (m-CPP) challenges. Reduced neuroendocrine responses, 'high' feelings and increased 'activation-euphoria' following m-CPP have been interpreted as indicating 5-HT alterations in a variety of psychiatric conditions. Significantly lower levels of HDL cholesterol were found in patients who had a history of aggression (P=0.005). Lower levels of HDL cholesterol were also found to be significantly associated with more intense 'high' and 'activation-euphoria' responses as well as with blunted cortisol responses to m-CPP (P=0.033, P=0.025 and P=0.018, respectively). This study gives further support to existing evidence indicating that in some individuals, the probability of exhibiting impulsive and violent behaviors may be increased when cholesterol is low. It also suggests that low cholesterol and alterations in 5-HT activity may be causally related.

Serum cholesterol, suicidal tendencies, impulsivity, aggression, and depression in adolescent psychiatric inpatients

BACKGROUND

This study was undertaken to examine the relationship between serum cholesterol levels and suicidal behaviors in adolescent psychiatric inpatients. Any association between serum cholesterol and measures of suicidal behavior, impulsivity, aggression, anxiety, and depression was also examined.

METHODS

Consecutive admissions (n = 152) to an adolescent psychiatric inpatient unit were assessed using measures of suicidal behavior, violence, impulsivity, and depression. Serum cholesterol was compared between those admitted for reasons of suicidal tendencies and those for other reasons. Correlation between serum cholesterol and measures of suicidal behavior, violence, impulsivity, and depression were examined.

RESULTS

Serum cholesterol levels were significantly higher in adolescent patients who were currently suicidal than in nonsuicidal adolescents. Within the suicidal group, but not in the total inpatient group, serum cholesterol correlated negatively with the degree of suicidal behavior. No correlation between serum cholesterol levels and depression, violence, and impulsivity were detected. No significant differences were found in serum cholesterol levels between diagnoses or between suicidal and nonsuicidal patients within each diagnostic group.

CONCLUSIONS

The association between cholesterol and suicidal tendencies remains complex and may depend on several variables within the population studied. Its usefulness as a biologic risk factor in clinical samples remains to be determined.

Assessing the observed relationship between low cholesterol and violence-related mortality. Implications for suicide risk

Health advocacy groups advise all Americans to restrict their dietary intake of saturated fat and cholesterol as an efficacious and safe way to lower plasma cholesterol concentrations and thus reduce the risk of coronary heart disease and other atherosclerotic disorders. However, accumulating evidence suggests that naturally low or clinically reduced cholesterol is associated with increased nonillness mortality (principally suicide and accidents). Other evidence suggests that such increases in suicide and traumatic death may be mediated by the adverse changes in behavior and mood that sometimes accompany low or reduced cholesterol. These observations provided the rationale for an ongoing series of studies in monkeys designed to explore the hypothesis that alterations in dietary or plasma cholesterol influence behavior and that such effects are potentiated by lipid-induced changes in brain chemistry. In fact, the investigations in monkeys reveal that reductions in plasma cholesterol increase the tendency to engage in impulsive or violent behavior through a mechanism involving central serotonergic activity. It is speculated that the cholesterol-serotonin-behavior association represents a mechanism evolved to increase hunting or competitive foraging behavior in the face of nutritional threats signaled by a decline in total serum cholesterol (TC). The epidemiological and experimental data could be interpreted as having two implications for public health: (1) low-cholesterol may be a marker for risk of suicide or traumatic death and (2) cholesterol lowering may have adverse effects for some individuals under some circumstances.

Hypothalamic-pituitary-adrenal axis function and platelet serotonin concentrations in depressed patients

Plasma cortisol and platelet serotonin (5-hydroxytryptamine, 5-HT) concentrations were determined in 39 male psychotic and 39 male non-psychotic depressed inpatients, and in 69 male healthy control subjects. Psychotic or non-psychotic depressed patients had higher predexamethasone plasma cortisol levels than found in the control group. After the dexamethasone suppression test (DST), psychotic and non-psychotic depressed patients were subdivided into suppressors and non-suppressors. Psychotic and non-psychotic patients had significantly different platelet 5-HT concentrations among themselves and compared with the control group. However, there was no significant correlation between plasma cortisol levels and platelet 5-HT concentrations. Dexamethasone administration did not affect platelet 5-HT concentrations within subtypes of depressed patients. Abnormal cortisol suppression after the DST occurred more frequently in psychotic than in non-psychotic patients. Platelet 5-HT and plasma cortisol concentrations were decreased in patients with pronounced suicidal behaviour. Our results suggest that plasma cortisol and platelet 5-HT concentrations might serve as independent biological markers for different subtypes of depression.

Lower serum high-density lipoprotein cholesterol (HDL-C) in major depression and in depressed men with serious suicidal attempts: relationship with immune-inflammatory markers

Recently, there have been some reports that changes in serum lipid composition may be related to suicide, major depression and immune-inflammatory responses. Findings from our laboratory suggest that major depression is accompanied by reduced formation of cholesteryl esters and perhaps by impairment of reverse cholesterol transport. The latter is reportedly accompanied by lower serum high-density lipoprotein cholesterol (HDL-C). The aim of this study was to examine whether (i) major depression is accompanied by lower serum HDL-C or by abnormal levels of serum total cholesterol, triglycerides, low-density lipoprotein-C (LDL-C) or vitamin E, (ii) suicidal attempts are related to lower serum HDL-C and (iii) there are significant associations between serum HDL-C and immune/inflammatory markers. A total of 36 subjects with major depression, of whom 28 patients showed treatment resistance, as well as 28 normal control subjects, had blood sampled for the assay of the above lipids, serum zinc (Zn), albumin (Alb) and flow cytometric determination of the T-helper/T-suppressor (CD4+/CD8+) T-cell ratio. In total, 28 depressed subjects had repeated measures of these variables both before and after treatment with antidepressants. Serum HDL-C and total cholesterol, as well as the HDL-C/cholesterol ratio, were significantly lower in subjects with major depression than in normal controls. Serum HDL-C levels were significantly lower in depressed men who had at some time made serious suicidal attempts than in those without such suicidal behaviour. Treatment with antidepressants for 5 weeks did not significantly alter either serum HDL-C or other lipid variables. Serum HDL-C levels were significantly and negatively correlated with the (CD4+/CD8+) T-cell ratio, and positively correlated with serum Alb and Zn. These results suggest that (i) lower serum HDL-C levels are a marker for major depression and suicidal behaviour in depressed men, (ii) lower serum HDL-C levels are probably induced by the immune/inflammatory response in depression and (iii) there is impairment of reverse cholesterol transport from the body tissues to the liver.

Low serum cholesterol in suicide attempters

Previous studies have shown an association between low serum cholesterol concentration and suicide; however, conflicting results have also been reported. To examine this potential association, cholesterol levels in 99 patients admitted to an emergency ward following an attempted suicide were compared with those in 74 nonsuicidal psychiatric inpatients, and those in 39 psychiatrically normal individuals with accidental injuries. Cholesterol concentrations in suicide attempters were found to be significantly lower compared with both psychiatric and normal controls, when sex, age, psychiatric diagnosis, and physical conditions (serum total protein and red blood cell count) were adjusted for. This significant relationship was observed in mood disorders and personality or neurotic disorders, but not in schizophrenia spectrum disorders. These results support the previous claim that lower cholesterol level is associated with an increased risk of suicidal behavior.

Cholesterol and mental disorder

BACKGROUND

Cholesterol plays an important part in cellular structure and function and changes in serum levels may affect neurotransmission in the central nervous system.

METHOD

A MEDLINE literature search was made covering the period 1990-95 with systematic searching of citations from the articles identified. Representative articles were selected, focusing on those aspects which had not been thoroughly reviewed elsewhere, namely suicidal ideation, depression, personality and schizophrenia.

RESULTS

Lowering cholesterol levels have been associated with an increase in violent deaths in cardiovascular primary prevention studies. However, altered cholesterol levels have also been reported in relation to other psychiatric disorders.

CONCLUSION

There is substantial evidence that serum cholesterol levels may be associated with variations in mental state or personality. Further work is needed to clarify this and to elucidate the mechanisms involved.