Total serum cholesterol in relation to psychological correlates in parasuicide

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

OBJECTIVES

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

METHOD

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

RESULTS

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

CONCLUSION

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

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.

ABCA1 Polymorphism, a Genetic Risk Factor of Harm Avoidance

Abstract. Even though cholesterol homeostasis and self-harm behaviors have shown to be associated, gene polymorphisms of the cholesterol system have not been studied yet in the context of self-harm related personality traits. Here we present an association study between six ABCA1 polymorphisms and temperament scales measured by Cloninger’s Temperament and Character Inventory on 253 young adults. An association between ABCA1 rs4149264 and harm avoidance has been observed. This association remained significant after Bonferroni correction. Haplotype analysis confirmed an independent association between rs4149264 and harm avoidance. ABCA1, a cholesterol homeostasis gene, is a candidate gene for harm related personality traits.

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.

Effect of a human serotonin 5-HT2A receptor gene polymorphism on impulsivity: Dependence on cholesterol levels

BACKGROUND

Impulsivity is multidimensional: Low impulse control may result in behavioural disorders, but acting on the spur of moment may also be advantageous. Previous studies have shown negative associations between different facets of impulsivity and serotonergic function. Other investigations have found negative correlations between serum lipid levels and impulsivity.

METHODS

We have investigated whether the functional polymorphism -1438A/G in the serotonin 5-HT_2A receptor gene (HTR2A) is associated with impulsivity levels and whether there is any interaction with serum lipid levels. This analysis was based on data of the population-representative Estonian Children Personality Behaviour and Health Study at age 25. Impulsivity was self-reported with the Adaptive and Maladaptive Impulsivity Scale.

RESULTS

Subjects with the A/A genotype of the HTR2A -1438A/G polymorphism had higher scores of Maladaptive impulsivity, but not Adaptive impulsivity. In females, high LDL and total cholesterol levels increased the genotype effect. In males, in the highest quartile of total or LDL cholesterol the genotype effect was altered, with G/G homozygotes having the highest Maladaptive impulsivity levels.

LIMITATIONS

Only one cohort of the European Youth Heart Study (EYHS) was used in the current study and impulsivity measures were self-reported.

CONCLUSIONS

Our results do not support the notion that low cholesterol levels universally lead to higher impulsivity, but it was found that high total and LDL cholesterol levels moderate the effect of the HTR2A gene promoter polymorphism. This suggests that future studies on impulsivity need to consider the interaction of serotonergic measures with the whole range of cholesterol levels.

Lipids and polyunsaturated fatty acid levels in deliberate self-harm: a 10-year follow-up study

OBJECTIVES

To evaluate if n-3 polyunsaturated fatty acids (PUFAs) and lipid levels are associated with episodes of self-harm or depression over a 10-year period.

METHODS

We included 40 individuals who self-harmed and 40 controls. Episodes of self-harm and depression were ascertained and levels of depression, impulsivity, suicidal ideation and plasma lipid levels measured at baseline and at 10-year follow-up.

RESULTS

Further episode(s) of self-harm occurred in 26% of cases. Omega-3 PUFAs or lipids were not predictive of depressive or self-harm episodes. Baseline eicosapentaenoic acid levels were modestly correlated with suicidal ideation at follow-up and dihomo-γ-linolenic acid and arachidonic acid were modestly correlated with motor impulsivity at follow-up in cases.

CONCLUSIONS

Despite significant negative correlations at baseline between plasma lipids, n-3 PUFAs and psychopathology, these levels were not predictive of clinical outcome over a 10-year period. Further research however is required due to the relatively low sample size and the risk of selection bias due to loss to follow-up in this study.

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.

A controlled study of serum lipid profiles in Indian patients with depressive episode

BACKGROUND

Lower levels of circulating lipid fractions and cholesterol are risk factors for impulsivity and depressive disorder. A lower level of serum cholesterol is also associated with patients presenting with history of self-harm.

MATERIALS AND METHODS

A total of 30 depressive patients and 30 healthy matched control subjects were recruited from the department of Psychiatry of a tertiary care hospital. We measured serum total cholesterol (TC), low-density lipoprotein (LDL) and high-density lipoprotein cholesterol and triglyceride levels of both patient and control group.

RESULTS

The serum TC and LDL-cholesterol levels were found to be significantly lower in study group than that of control group.

CONCLUSION

Lower levels of serum cholesterol are associated with depressive disorder.

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.

Obesity and suicide risk in adults--a systematic review

BACKGROUND

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

METHODS

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

RESULTS

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

DISCUSSION

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

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.

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 total cholesterol correlates positively to central serotonergic turnover in male but not in female subjects

Reduced central serotonergic activity and low total serum cholesterol have been related to increased aggression, violent behavior, and suicidality. Searching for a correlation between them, we estimated serum total cholesterol and CSF levels of the main serotonin metabolite 5-HIAA in medication free male and female subjects for whom diagnostic lumbar puncture was performed. To eliminate age influence, we included in the study subjects in the age range 26 to 45years. In a group of 62 subjects (30 males), found negative after diagnostic neurological examination, the correlation was not significant for the whole group, but after sex stratification, a significant positive correlation was revealed for males but not for females. These results were replicated in a second group of 76 subjects (31 males) with clinical and laboratory findings suggestive of multiple sclerosis (clinically isolated syndrome). The results link low cholesterol to low serotonergic activity only in males, predisposing them for violent and risky behaviors. This phenomenon could be seen as an evolutionary trait, possibly a result of the distinct role of males in a hunter-gatherer environment of evolutionary adaptedness, and may contribute to the understanding of the higher incidence of violent behavior observed in males.

Suicide neurobiology

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

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

Lipid-lowering medication use and aggression scores in women: a report from the NHLBI-sponsored WISE study

AIM

The aim of this study was to examine the association between the use of lipid-lowering medication and aggressive responding, hostility, cynicism, and depression scores in women undergoing coronary angiography.

METHODS

The cohort included 498 women from the National Heart, Lung and Blood Institute (NHLBI)-sponsored Women's Ischemia Syndrome Evaluation (WISE) study. WISE is a four-center study of women with chest pain who underwent quantitative coronary angiography for suspected myocardial ischemia. The psychosocial indices included the Cook Medley Hostility questionnaire, measuring aggression, hostility, and cynicism, and the Beck Depression Inventory (BDI).

RESULTS

Compared to those not on lipid-lowering medication, women receiving lipid-lowering pharmacotherapy were older (62 vs. 55 years, p < 0.001) and had more hypertension, dyslipidemia, diabetes, and coronary artery disease (CAD, defined as > or =50% stenoses in at least one epicardial artery) (all p < 0.003). Women on lipid-lowering medication had higher aggressive responding scores than those not on medication, 3.0 +/- 1.8 vs. 2.7 +/- 1.7, respectively (age-adjusted p < 0.003). This association persisted after adjustment for coronary risk factors, education, and extent of angiographic disease (CAD) (p < 0.005), and after exclusion of women using psychotropic medications (p < 0.001). Hostility, cynicism, and depression scores did not differ by medication use.

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.

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.

ABCG1 gene variants in suicidal behavior and aggression-related traits

The ABCG1 transporter seems to be involved in human cholesterol and sterol homeostasis. As alterations in cholesterol homeostasis have been widely linked to aggression, violence and suicidal behavior, we considered ABCG1 as a candidate gene for these traits. We studied 5 gene variants of ABCG1 in a sample of 571 suicide attempters, healthy controls and suicide completers. We also analyzed the relation to aggression-related traits, assessed by STAXI and FAF. Regarding the genotypes, there was no association with completed or attempted suicide with the tested SNPs. Regarding alleles, only one SNP (rs1044317) showed a slight association with suicide attempters in comparison to the controls. Interestingly, rs225374 G allele carriers had higher scores on the STAXI subscales "State Anger" and "Anger Out", as well as on the FAF subscales "Spontaneous Aggression", "Irritability" and "Aggression". Carriers of the rs914189 G allele scored higher on the FAF subscales "Spontaneous Aggression", "Reactive Aggression" and "Aggression". Carriers of the rs1044317 G allele had lower scores for STAXI "Trait Anger" and "Trait Temperament", and higher scores for STAXI "Anger Control". Our results provide evidence that the ABCG1 may influence aggression-related traits. Given that these represent intermediate phenotypes of suicidal behavior, ABCG1 might also act on suicidal behavior through these traits. The observed associations warrant further replications.

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.

Effects of Statin Use on Muscle Strength, Cognition, and Depressive Symptoms in Older Adults

OBJECTIVES

To determine the relationship between hydroxymethyl glutaryl coenzyme A reductase inhibitor (statin) use and proximal muscle strength, cognition, and depression in older adults.

DESIGN

Observational cohort study.

SETTING

Outpatient primary care clinics.

PARTICIPANTS

Seven hundred fifty-six community-dwelling veterans aged 65 and older.

MEASUREMENTS

Timed chair stands (a measure of proximal muscle strength), Trail Making Test Part B (a measure of cognition), and the Center for Epidemiologic Studies Depression Scale score were measured at baseline and 1-year follow-up. Participants were assessed for statin prescriptions (and indications for or contraindications to their use), concomitant medication use, comorbidities, and other potential confounders.

RESULTS

Statin users (n=315) took a mean 6.6 medications, versus 4.6 for nonusers (n=441), and had a median duration of statin use of 727 days. Statin users were more likely to be white and had (as expected) more cardiac, cerebrovascular, and peripheral vascular disease. Based on multivariable models adjusting for pertinent covariates, statin users performed modestly better than nonusers for timed chair stands (-0.5 seconds; P=.04), Trail Making Test Part B (-7.7 seconds; P=.08), and depression scores (-0.2 points; P=.49) at follow-up. Of potentially high-risk participants (based on age, comorbidity, and number of medications), statin users also showed similar 1-year changes as nonusers, although worsened depression scores were found in those with greater comorbidity (+0.88 points; P=.10).

CONCLUSION

Older, community-dwelling male participants taking maintenance statin therapy had similar outcomes to those of nonusers in tests of muscle strength, cognition, and depression, but further examination of benefits and harms in different subgroups is warranted.

Lipids and essential fatty acids in patients presenting with self-harm

BACKGROUND

Low cholesterol has been reliably demonstrated in people who self-harm.

AIMS

To determine whether people who self-harm also have low levels of essential fatty acids (EFAs) and to examine associations between the EFAs and serotonergic function.

METHOD

Depression, impulsivity and suicidal intent were measured in patients with self-harm (n=40) and matched controls, together with plasma lipids and EFAs. Platelet serotonergic studies were carried out in a subgroup (n=27).

RESULTS

Patients with self-harm had significantly more pathology on all psychometric measures, lower mean total cholesterol levels (4.18 (s.d.=0.93) v. 4.87 (s.d.=0.83) mmol/l, P=0.003) and lower mean total EFA levels (89. 5 (15.6) v.103.7 (17.1) microg/ml, P=0.0001) than controls after adjustment for confounding variables. Total n-3 and n-6 EFA levels were also significantly lower. Impulsivity and depression scores were significantly inversely correlated with both n-6 EFAs and n-3 EFAs, but were not associated with total or low-density lipoprotein cholesterol levels. Platelet serotonergic measures did not differ between groups, and were not related to psychobiological measures.

CONCLUSIONS

Lower plasma EFA levels combined with low cholesterol concentrations were associated with self-harm as well as impulsivity and affect. This was not related to platelet serotonergic measures.

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.

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.

Total serum cholesterol and suicidality in anorexia nervosa

OBJECTIVE

No published study has evaluated the relationship between serum cholesterol and suicidality in anorexia nervosa (AN).

AIMS

To assess psychiatric and nutritional correlates of serum cholesterol in a sample of AN patients.

METHODS

Serum cholesterol and nutritional status were evaluated in a sample of 74 AN patients, before starting any type of refeeding. All subjects underwent a structured clinical interview and completed the Hopkins Symptom Checklist.

RESULTS

Subjects who reported previous suicide attempts, impulsive self-injurious behavior, or current suicidal ideation showed significantly lower cholesterol levels than subjects without suicidality. Cholesterol levels were negatively correlated with the severity of depressive symptoms in all the patients with the exception of those with recurrent binge eating. A multivariate analysis showed that the relationships between cholesterol levels and suicidal behavior and ideation do not seem to be affected by the nutritional and metabolic factors considered in the study.

CONCLUSIONS

Notwithstanding the influence of important metabolic factors affecting cholesterolemia in AN, our research tends to confirm previous studies that have found an association between low cholesterol levels and suicidality.

Hormonal changes with cholesterol reduction: a double-blind pilot study

BACKGROUND

The lowering of high serum cholesterol levels may be associated with increased non-cardiac mortality due to behavioral changes, although such endpoints are likely rare.

OBJECTIVE

This current study sought to determine if hormonal changes accompany pharmacologically induced decreases in serum cholesterol levels.

METHOD

Cholesterol, dopamine, homovanillic acid (HVA), serotonin, 5-HIAA, testosterone, cortisol and pregnenolone were measured at baseline and after 4 weeks of treatment.

RESULTS

Subjects' cholesterol levels significantly declined within 4 weeks. Concomitant significant increase in dopamine and HVA were noted.

CONCLUSION

Although this study is limited in size, it raises the possibility that cholesterol-lowering drug treatment is associated with hormonal perturbations.

Investigation of completed suicide and genes involved in cholesterol metabolism

BACKGROUND

Several lines of evidence support the association between low or lowered levels of serum total cholesterol and suicide. Genetic epidemiological studies suggest that genes predispose to suicide. Given that genes control many aspects of cholesterol biosynthesis and metabolism, one approach through which to explore the putative association between low cholesterol and suicide is through genetic studies.

METHODS

We examined the potential role of five genes encoding proteins involved in cholesterol biosynthesis and transport in a total sample of 305 male Caucasian subjects, consisting of 145 suicide completers and 160 controls. We investigated variation in the HMG CoA reductase (HMGCR), 7-dehydrocholesterol reductase (DHCR7), lipoprotein lipase (LPL), low-density lipoprotein receptor (LDLR), and apolipoprotein E (APOE) genes.

RESULTS

We were unable to detect significant differences in allele or genotype frequencies between the suicide cases and controls for any of the genes studied. No relationship was found between genotype and impulsivity or aggression as measured using the BIS and BDHI, respectively.

LIMITATIONS

The limitations of this study are consistent with the typical limitations inherent in most genetic association studies involving complex behavioral traits.

CONCLUSION

Although these genes are unlikely to play a major role in susceptibility to suicide, further studies in a larger sample are necessary to reveal the smaller genetic effects, if present.

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.

The determinants of attempted suicide in a general hospital setting in Fiji Islands: a gender-specific study

The objective of the study was to examine the sociodemographic and clinical factors influencing gender-specific attempted suicide. Suicide attempters, 40 males and 88 females, seen on a consultation-liaison psychiatric service over a period of 42 months (from January 1, 1999 to June 30, 2002) were compared on sociodemographic and clinical variables. The female attempters [22.99 years (SD 8.1)] were younger than their male counterparts [25.15 years (SD 9.5)] [P = 0.0002]. A higher proportion of the male attempters were engaged in outside occupations, compared with their female counterparts who were mainly full-time housewives or engaged in domestic duties [P = 0.003]. Alcohol misuse was more associated with male suicide attempts [P = 0.001]. Ninety percent of male attempters and 54.6% of the female attempters had the intention to die [P = 0.001]. Although depressive episode was the most common psychiatric disorder in male attempters, followed by neurotic and stress-related disorders, while neurotic and stress-related disorders ranked first in female attempters followed closely by depressive episode, the difference was not significant. However, significantly more male attempters required pharmacotherapy and psychological intervention than their female counterparts [P = 0.002]. More females had marital difficulties, although comparing the two groups on social difficulties did not yield a significant difference. Method used, personality disorders, previous attempt, repeat attempt, race, religion, and marital status were not significant distinguishing factors. Younger age, lack of employment outside home, marital problems, and nondeath motives were more influential in female attempted suicide, while alcohol misuse and severe psychiatric morbidity were more frequently associated with male attempted suicide. The findings support gender-specific preventive and interventional strategies.

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 cholesterol and impulsivity in a large sample of healthy young men

Studies that have investigated the association between cholesterol levels and impulsivity are relatively few in number and have yielded equivocal results. In this study, we investigated the relationship between impulsivity, depression and serum lipids [total cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides] in a large sample (N=2051) of healthy young men who were remarkably homogeneous in terms of age, educational level, and socioeconomic conditions. Depression was assessed using the depression scale of the Minnesota Multiphasic Personality Inventory-2, and impulsivity was measured using the impulse control scale of the Big Five Questionnaire (BFQ). We found that subjects with a low serum cholesterol, defined as the lowest tenth of the total cholesterol distribution (< or =3.7 mmol/l), scored significantly lower on the impulse control scale of the BFQ. There was no significant association between depression and cholesterol concentrations. In addition, in a multiple regression model, both lower levels of total cholesterol and higher levels of HDL cholesterol emerged as significant predictors of impulsivity. However, since the regression model accounted for only 0.6% of the variance in the score on the impulse control scale of the BFQ, the biological significance of these correlations was negligible. Taken together, these findings suggest that, in healthy young men, a relationship between cholesterol and impulsivity emerges only when the statistical analysis focuses on subjects with very low levels of cholesterol.

Behavioral implications of lowering cholesterol levels: a double-blind pilot study

The treatment of hypercholesterolemia may be associated with greater noncardiac mortality. This current pilot study sought to determine which behaviors, if any, are associated with decreases in cholesterol level. Twelve subjects received one of two cholesterol-reducing drugs or placebo. Cholesterol and behavioral ratings were measured at baseline, 4, and 52 weeks with standardized scales. Cholesterol levels markedly declined with concomitant significant increases in impulsivity ratings at 4 weeks. At 52 weeks, the increase in impulsivity ratings was no longer apparent, but depression ratings showed a significant improvement. This pilot study, although limited in size, raises the possibility that cholesterol-lowering drugs are associated with mild, time-limited increases in impulsivity and with mild, time-delayed improvements in depression ratings.

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.

Relationship between attempted suicide, serum cholesterol level and novelty seeking in psychiatric in-patients

This study sought to compare the serum cholesterol levels of psychiatric in-patients, with and without recent suicidal behavior. The hypothesis was that the temperament dimension novelty seeking (NS) would be an intermediary variable, correlated with both serum cholesterol level and suicidal behavior. The study included 155 psychiatric in-patients, 21.9% (n=34) of whom had recently attempted suicide. Their cholesterol level was compared to that of patients with no suicide attempt. The NS dimension was explored with the aid of Cloninger's Temperament and Character Inventory. Significantly lower average cholesterol levels were found in women who had attempted suicide before hospitalization than for the others (4.71 mmol/l+/-0.83 vs. 5.52 mmol/l+/-1.36). Similar results were not found for men. However, the average NS scores did not differ according to suicide attempts in women or in men, and the scores of NS were not correlated with cholesterol level. This study confirms an association between low cholesterol and suicidal behavior in women only, but this association seems independent from the NS personality dimension. The absence of a correlation between serum cholesterol levels and suicidal behavior in men could be linked to the small number of men included in the study.

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.

Serum cholesterol, suicidal behavior and impulsivity in cocaine-dependent patients

Relationships between serum cholesterol and suicidal behavior have been reported. As suicidal behavior is common in cocaine dependence, we looked for a relationship with serum cholesterol. To do this, we compared 57 cocaine-dependent patients who had attempted suicide with 111 cocaine-dependent patients who had never attempted suicide for their admission total serum cholesterol levels. We found that there were no significant differences between cocaine-dependent patients who had or had not attempted suicide in their total serum cholesterol levels. Also, there were no significant correlations between total serum cholesterol levels and scores on the Barratt Impulsivity Scale. Thus, admission total serum cholesterol does not appear to be clinically useful in the assessment of suicidal behavior in cocaine-dependent patients.

Cholesterol reduction and non-illness mortality: meta-analysis of randomised clinical trials

OBJECTIVE

To investigate the association between cholesterol lowering interventions and risk of death from suicide, accident, or trauma (non-illness mortality).

DESIGN

Meta-analysis of the non-illness mortality outcomes of large, randomised clinical trials of cholesterol lowering treatments.

STUDIES REVIEWED

19 out of 21 eligible trials that had data available on non-illness mortality. INTERVENTIONS REVIEWED: Dietary modification, drug treatment, or partial ileal bypass surgery for 1-10 years.

MAIN OUTCOME MEASURE

Deaths from suicides, accidents, and violence in treatment groups compared with control groups.

RESULTS

Across all trials, the odds ratio of non-illness mortality in the treated groups, relative to control groups, was 1.18 (95% confidence interval 0.91 to 1.52; P=0.20). The odds ratios were 1.28 (0.94 to 1.74; P=0.12) for primary prevention trials and 1.00 (0.65 to 1.55; P=0.98) for secondary prevention trials. Randomised clinical trials using statins did not show a treatment related rise in non-illness mortality (0.84, 0.50 to 1.41; P=0.50), whereas a trend toward increased deaths from suicide and violence was observed in trials of dietary interventions and non-statin drugs (1.32, 0.98 to 1.77; P=0.06). No relation was found between the magnitude of cholesterol reduction and non-illness mortality (P=0.23).

CONCLUSION

Currently available evidence does not indicate that non-illness mortality is increased significantly by cholesterol lowering treatments. A modest increase may occur with dietary interventions and non-statin drugs.

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.