Are Lipids Possible Markers of Suicide Behaviors?

Association between fluctuations in blood cholesterol levels and the risk of suicide death in the general population

OBJECTIVE

Suicide is a pressing global public health issue. While recent studies have explored the association between serum cholesterol levels and suicide risk, the association between cholesterol variability and suicide risk is not well characterized.

METHODS

This was a nationwide population-based cohort study using data from the Korean National Health Insurance Service database. A total of 1,983,701 patients with at least three measurements of TC between 2004 and 2009 were included. Participants were followed until death by suicide or the study's end in December 2021. Participants were categorized based on baseline TC or TC variability. TC variability was assessed using coefficient of variation (CV), variability independent of the mean (VIM), and average successive variability (ASV).

RESULTS

Over a median follow-up of 11 years, 5883 (0.3 %) patients died by suicide. Compared to subjects with TC <200 mg/dL, those with TC ≥240 mg/dL had a lower risk of suicide death (hazard ratio [HR]: 0.85, 95 % confidence interval [95 % CI]: 0.78-0.93). In the unadjusted model, the HR for suicide death in the highest quartile (Q4) compared to the lowest quartile (Q1) of TC variability was 1.36 (95 % CI: 1.26-1.46). After adjusting for potential confounders, high variability in TC levels was associated with a higher risk of suicide death (HR 1.27, 95 % CI: 1.18-1.37). When analyzed based on the combination of TC baseline and variability, the highest quartile of TC variability showed a higher rate of suicide death compared to the lowest quartile, regardless of baseline TC level.

CONCLUSION

High TC variability and low TC levels were associated with an increased risk of suicide.

Association and interaction between overweight/obesity and suicide attempts in young first-episode and drug-naïve patients with major depressive disorder

Aims

This research's objective was to explore the correlation of overweight/obesity and suicide attempts in young patients with major depressive disorder (MDD) and the related factors of suicide attempts in patients with/without overweight/obesity.

Methods

This study included 520 young patients with MDD who were first-episode and drug-naïve (FEDN), with an average age of 20.50 ± 2.36 years. Height and weight of each subject were measured, and overweight was classified as 24≤BMI<28, and obesity as BMI≥28.Biochemical indicators were detected including blood glucose, lipid, and thyroid function indicators. Depressive symptoms, anxiety symptoms, and psychotic symptoms were evaluated using Hamilton Rating Scale for Depression (HAMD), Hamilton Anxiety Rating Scale (HAMA) and Positive and Negative Syndrome Scale (PANSS) positive subscale, respectively.

Results

Overweight/obesity was a separate factor influencing suicide attempts in subjects(p < 0.05, OR = 0.57, 95%CI: 0.34-0.95). Higher HAMD, HAMA scores, levels of total cholesterol (TC), thyroid stimulating hormone (TSH), and prevalence of thyroid peroxidase antibody abnormalities were seen in overweight/obese individuals who attempted suicide(all p values < 0.01).While in patients without overweight/obesity, those who attempted suicide had higher HAMD, HAMA, PANSS positive subscale scores, levels of TSH, fasting blood glucose, TC, blood pressure, prevalence of TSH abnormalities, and lower levels of high-density lipoprotein cholesterol(all p values < 0.01).

Conclusions

In young FEDN patients with MDD, overweight/obesity might influence the incidence of suicide attempts and related influences.

Gender difference in the relationship between clinical symptoms, thyroid hormones, and metabolic parameters in young, first-episode and drug-naïve major depressive disorder patients with suicide attempts: A network analysis perspective

BACKGROUND

Suicide attempts are one of the most serious comorbidities in patients with major depressive disorder (MDD), and the prevalence of suicide attempts is higher in younger people compared to older people, with significant gender differences. This study aimed to investigate the relationship between suicide attempts, clinical symptoms, thyroid hormones, and metabolic parameters in young first-episode and drug-naïve (FEND) MDD patients of different genders.

METHODS

A total of 1289 FEND MDD patients were recruited. Depression, anxiety, and psychotic symptoms were assessed using the Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA), and the Positive and Negative Syndrome Scale (PANSS) positive subscale, respectively. Thyroid hormones and glucolipid metabolism indicators were also tested. Network analysis was employed to delineate the interplay between thyroid dysfunction, clinical symptoms, and metabolic disorders.

RESULTS

Among young FEND MDD patients, the rate of suicide attempts was 17.4% in males and 19.8% in females, showing no significant gender difference in the incidence of suicide attempts (χ2 = 1.06, p = 0.303). In the network model, PANSS positive subscale (Expected Influence = 0.578) and HAMD scores (Expected Influence = 0.576) were identified as the individual symptoms that most affected male patients, whereas TSH (Thyroid-Stimulating Hormone) (Expected Influence = 0.972) and PANSS positive subscale (Expected Influence = 0.937) were identified as the individual symptoms that most affected female patients. In addition, we found that TSH (Expected Influence = 0.438) was a pivotal node connecting metabolic disturbances and clinical symptoms.

CONCLUSION

Our findings emphasize the important role of psychotic symptoms in young MDD patients with suicide attempts. Moreover, our results highlight the pivotal role of serum TSH levels in the pathophysiology of young female MDD patients with suicide attempts.

Prevalence, demographic characteristics, and clinical features of suicide risk in first episode drug-naïve schizophrenia patients with comorbid severe anxiety

BACKGROUND

Both anxiety symptoms and suicide risk are common in schizophrenia. However, previous findings about the association between anxiety and suicide risk in schizophrenia were controversial. This study is the first to examine the prevalence of suicide risk and related demographic, clinical features in a large sample of first episode drug-naïve (FEDN) schizophrenia patients with comorbid severe anxiety.

METHODS

In total, 316 patients with FEDN schizophrenia were enrolled in this study. Patients' symptoms were assessed using the Hamilton Depression Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA), and Positive and Negative Syndrome Scale (PANSS). Serum levels of glucose, insulin, uric acid, and lipids including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), were evaluated.

RESULTS

In the current study, 56.3% patients presented comorbid severe anxiety. The rate of suicide risk was higher in the severe anxiety group (55.6%) than in the mild-moderate anxiety group (33.3%). The interactions among severe anxiety, uric acid and HDL-C were associated with suicide risk. Compared with patients with normal uric acid, those with abnormal uric acid exhibited a stronger association between HAMA scores and HAMD-suicide item scores. This enhanced association was also observed for patients with abnormal HDL-C levels.

CONCLUSIONS

In FEDN schizophrenia patients with comorbid severe anxiety, our findings suggested a high incidence of suicide risk. Abnormal levels of uric acid and low levels of HDL-C, as well as high depression may be associated with an increased risk of suicide in FEDN schizophrenia patients with comorbid severe anxiety.

Mortality and adverse events associated with statin use in primary care patients with depression: a real-world, population-based cohort study

BACKGROUND

New National Institute for Health and Care Excellence (NICE) guidance endorses the prescription of statins in larger population groups for the prevention of cardiovascular and cerebrovascular morbidity and mortality, especially in people with severe mental illness. However, the evidence base for their safety and risk/benefit balance in depression is not established.

OBJECTIVES

This study aims to assess the real-world mortality and adverse events of statins in depressive disorders.

METHODS

Population-based, nationwide (England), between-subject, cohort study. We used electronic health records (QResearch database) of people aged 18-100 years with first-episode depression, registered with English primary care practices over January 1998-August 2020 for 12(+) months, divided into statin users versus non-users.Primary safety outcomes included all-cause mortality and any adverse event measured at 2, 6 and 12 months. Multivariable logistic regression was employed to control for several potential confounders and calculate adjusted ORs (aORs) with 99% CIs.

FINDINGS

From over 1 050 105 patients with depression (42.64% males, mean age 43.23±18.32 years), 21 384 (2.04%) died, while 707 111 (67.34%) experienced at least one adverse event during the 12-month follow-up. Statin use was associated with lower mortality over 12 months (range aOR2-12months 0.66-0.67, range 99% CI 0.60 to 0.73) and with lower adverse events over 6 months (range aOR2-6months 0.90-0.96, range 99% CI 0.91 to 0.99), but not at 1 year (aOR12months 0.99, 99% CI 0.96 to 1.03). No association with any other individual outcome measure (ie, any other neuropsychiatric symptoms) was identified.

CONCLUSIONS

We found no evidence that statin use among people with depression increases mortality or other adverse events.

CLINICAL IMPLICATIONS

Our findings support the safety of updated NICE guidelines for prescribing statins in people with depressive disorders.

The abnormalities of lipid metabolism in children and adolescents with major depressive disorder and relationship with suicidal ideation and attempted suicide

Background

Major depressive disorder (MDD) is a widespread health issue in many countries, which has an extremely negative impact on the health of children and adolescents in particular. In the context of depression and metabolic disorders, dyslipidemia and metabolism-related problems become more prominent comorbidities. However, they continue to be the main barrier to the successful recovery of the clinical progress. In this study we investigated the rate of dyslipidemia, additional risk factors among Chinese children and adolescents with MDD, and association of the suicidal behavior with lipid levels.

Methods

The study took 756 people from the Third People's Hospital of Fuyang between January 2020 and December 2021, aged between 8 and 18, with major depressive disorders diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). We determined the FBG (fasting blood glucose) and lipid parameters in all subjects and also investigated the history of suicidal ideation, the cases of attempted suicide, and the scores of depressive symptoms. Sociodemographic and clinical data were gathered and analyzed using the SPSS-23.0 version.

Results

The prevalence of hypercholesterolemia, hypertriglyceridemia, high LDL-C, and low HDL-C were 5.42 % (41/756), 10.58 % (80/756), 3.84 % (29/756) and 5.42 % (41/756) respectively. For hypercholesterolemia and hypertriglyceridemia, they were positive associated with suicidal ideation and suicide attempts, and the positive correlation is shown between low HDL-C levels and suicide attempts. Nevertheless, non-ideation and inversely suicidal attempts were not discovered among high-LDL-C subjects. Logistic analysis showed that high levels of FBG (OR = 2.86, 95 % CI: 1.31-6.25, P = 0.008) and worse LDL-C (OR = 357.82, 95 % CI: 66.16-1935.10, P < 0.001) are the independent associated factors for hypercholesterolemia. More hospitalizations (OR = 1.89, 95 % CI: 1.07-3.35, P = 0.028), obesity (OR = 2.55, 95 % CI: 1.25-5.18, P = 0.010), high levels of TC (OR = 2.15, 95 % CI: 1.03-4.48, P = 0.042), and higher doses of antidepressants (OR = 1.02, 95 % CI: 1.00-1.04, P = 0.029) were independently associated factors for hypertriglyceridemia, while high levels of HDL-C (OR = 0.11, 95 % CI: 0.04-0.31, P < 0.001) were protective factors. In addition, high levels of TC (OR = 113.94, 95 % CI: 20.01-648.85) were statistically different (P < 0.001) and suggested that the factor was significantly related to high LDL-C. Meanwhile, older age (OR = 1.25, 95 % CI: 1.02-1.52, P = 0.030) and high levels of TG (OR = 3.00, 95 % CI: 1.98-4.55, P < 0.001) were independent factors contributing to low HDL-C.

Conclusion

The high prevalence of dyslipidemia in childhood and adolescence among children and adolescents with depressive disorder has become a public health issue. Hypercholesterolemia and hypertriglyceridemia showed a positive correlation with suicidal thoughts and suicidal attempts. Monitoring the incidence of suicidal thoughts and attempts among them would carry some predictor meaning in therapy and for jumping back to health.

Prevalence and related factors of first-time suicide attempts in the past 14 days in Chinese adult patients with first-episode drug-naïve major depressive disorder

Background

This study aimed to identify socio-demographic, physiologic, and psychologic related factors of the first-time suicide attempt (FSA) in the past 14 days in Chinese adult patients with first-episode drug-naïve (FEDN) major depressive disorder (MDD).

Methods

A total of 1718 adult patients with FEDN MDD were enrolled in this cross-sectional survey. Depression, anxiety symptoms, and suicide attempts were assessed. Additionally, biological samples were collected and measured, while Logistic regression analysis was employed to explore the risk factors for FSA in the past 14 days among FEDN MDD patients.

Results

Among suicide attempters, 12.11% (208 out of 1718) reported experiencing FSA in the past 14 days. Logistic regression analysis showed that the risk factors for FSA included more severe anxiety symptoms (OR=1.37, 95%CI: 1.28-1.48, p<0.001), higher levels of total cholesterol (TC) (OR=1.42, 95%CI: 1.13-1.77, p=0.003), and elevated thyroid-stimulating hormone (TSH) (OR=1.13, 95%CI: 1.03-1.25, p=0.01). The regression model exhibited good discriminatory power for FSA with an area under the curve (AUC) of 0.82.

Conclusion

FEDN MDD patients with more severe anxiety and higher levels of TSH and TC are more likely to develop FSA in the past 14 days. These factors are risk factors for short-term (in the past 14 days) FSA and may serve as indicators for early intervention.

Elevated lipid class concentrations in females with anorexia nervosa before and after intensive weight restoration treatment-A lipidomics study

OBJECTIVE

To study the plasma lipidome of patients with anorexia nervosa (AN) before and after weight restoration treatment and report associations with AN subtypes and oral contraceptive pill (OCP) usage.

METHODS

Quantitative shotgun lipidomics analysis was used to study plasma lipids of 50 female patients with AN before and after weight restoration treatment and 50 healthy female controls (HC). The AN group was assessed with blood samples and questionnaires before and after weight restoration.

RESULTS

In total we quantified 260 lipid species representing 26 lipid classes of which 13 lipid class concentrations were elevated in patients with AN at admission compared with HC. Lipid classes remained elevated after weight restoration treatment of 84 days (median; interquartile range 28), and only the concentration of the ceramide lipid class increased between pre- and post-treatment (p = .03), whereas lysophosphatidylcholine (LPC, p = .02), ether-linked Phosphatidylcholine (LPCO, p = .02), and lysophosphatidylethanolamine (LPE, p = .009) decreased.

CONCLUSION

In AN, 13 out of 26 lipid class concentrations were elevated at admission and remained elevated post-treatment. Ceramides increased further between pre- and post-weight restoration treatment, which could be related to the rapid weight gain during re-nutrition. Further research is needed to elucidate the effects of weight restoration treatment on short- and long-term lipid profiles in individuals with AN.

PUBLIC SIGNIFICANCE STATEMENT

Lipidomics research can increase the understanding of AN, a complex and potentially life-threatening eating disorder. By analyzing lipids, or fats, in the body, we can identify biological markers that may inform diagnosis and develop more effective treatments. This research can also shed light on the underlying mechanisms of the disorder, leading to a better understanding of the processes involved in eating behavior.

Apolipoproteins and Suicide: A Potential Psychiatric Biomarker

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

Establishment of a risk prediction model for suicide attempts in first-episode and drug naïve patients with major depressive disorder

BACKGROUND

Suicide is common in patients with major depressive disorder (MDD) and has serious consequences for individuals and families. This study aims to establish a risk prediction model for suicide attempts in MDD patients to make the detection of suicide risk more accurate and effective.

METHODS

A cross-sectional survey, clinical examination, and biochemical indicator tests were performed on 1718 first-episode and drug naïve patients with major depressive disorder. We used Machine Learning to establish a risk prediction model for suicide attempts in FEDN patients with MDD.

RESULTS

Five predictors were identified by LASSO regression analysis from a total of 20 variables studied, namely psychotic symptoms, anxiety symptoms, thyroid peroxidase antibodies (ATPO), total cholesterol (TC), and high-density lipoprotein-cholesterol (HDL-C). The model constructed using the five predictors displayed moderate predictive ability, with an area under the ROC of 0.771 in the training set and 0.720 in the validation set. The DCA curve showed that the nomogram could be applied clinically if the risk threshold was between 22 % and 60 %. The risk threshold was found to be between 20 % and 60 % in external validation.

CONCLUSION

Introducing psychotic symptoms, anxiety symptoms, ATPO, TC, and HDL-C to the risk nomogram increased its usefulness for predicting suicide risk in patients with MDD. It may be useful in clinical decision-making or in discussions with patients, especially in crisis interventions.

Changes in Plasma TPH2, GDNF, Trk-b, BDNF, and proBDNF in People Who Died by Suicide

Recent studies have shown that neuropeptides and neurotrophic factors may be involved in the pathophysiological mechanisms of suicide. However, the current research on this aspect is still insufficient. Our study aimed to explore the biological patterns of suicide deaths, including levels of BDNF, proBDNF, BDNF/proBDNF, Trk-b, GDNF, and TPH2. The researchers selected 25 normal control patients matched by age with 30 suicide deaths. We used enzyme-linked immunosorbent assays to detect the levels of BDNF, proBDNF, BDNF/proBDNF, Trk-b, GDNF, and TPH2 in the plasma of suicide and control subjects. proBDNF, BDNF/proBDNF, Trk-b, GDNF, and TPH2 levels are shown as the median (25th-75th percentile). BDNF levels are shown as the mean (standard error of the mean). (1) The levels of plasma TPH2 and proBDNF in people who died by suicide were significantly higher than those in the control group. (2) The plasma levels of GDNF and BDNF/proBDNF in the suicide group were obviously lower than those in the control group. (3) There was no significant difference in plasma BDNF or Trk-b concentrations between the suicide group and the control group.Plasma TPH2, GDNF, and proBDNF levels are related to suicide. Plasma neurotrophic factor markers may predict suicide risk.

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

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

Prevalence of suicide attempts and correlates among first-episode and untreated major depressive disorder patients with comorbid dyslipidemia of different ages of onset in a Chinese Han population: a large cross-sectional study

BACKGROUND

Patients with dyslipidemia are at increased risk for suicide, especially those with major depressive disorder (MDD). Few studies have investigated the independent effects of suicide attempts on comorbid dyslipidemia in patients with MDD. Moreover, there are no comparisons of differences in factors associated with suicide attempts among patients with MDD with dyslipidemia at different ages of onset. The aim of this study was to investigate the prevalence of suicide attempts and associated variables in first episode and untreated patients with MDD with comorbid dyslipidemia at different ages of onset.

METHODS

We recruited 1718 patients with first-episode untreated MDD in this study. Demographical and clinical data were collected, and lipid profiles, thyroid function, and blood glucose levels were measured. The Hamilton Depression Scale 17 (HAMD-17), Hamilton Anxiety Scale (HAMA), Clinical Global Impression Severity Scale (CGI), and Positive and Negative Syndrome Scale (PANSS) positive subscale were assessed for depression, anxiety and illness severity, as well as psychotic symptoms, respectively.

RESULTS

The percentage of patients with MDD with comorbid dyslipidemia was 61% (1048/1718). Among patients with MDD with comorbid dyslipidemia, the incidence of suicide attempts was 22.2% (170/765) for early adulthood onset and 26.5% (75/283) for mid-adulthood onset. Independent factors associated with suicide attempts in early adulthood onset patients with MDD with dyslipidemia were as follows: HAMA score (B = 0.328, P < 0.0001, OR = 1.388), Suspicion /persecution (B = -0.554, P = 0.006, OR = 0.575), CGI (B = 0.878, P < 0.0001, OR = 2.406), systolic blood pressure (B = 0.048, P = 0.004, OR = 1.049), hallucinatory behavior (B = 0.334, P = 0.025, OR = 1.397), and TPOAb (B = 0.003, p < 0.0001, OR = 1.003). Independent factors associated with suicide attempts in mid-adulthood onset patients with MDD with comorbid dyslipidemia were as follows: HAMA score (B = 0.182, P < 0.0001, OR = 1.200), CGI (B = 1.022, P < 0.0001, OR = 2.778), and TPOAb (B = 0.002, P = 0.009, OR = 1.002).

CONCLUSION

Our findings suggest an elevated risk of suicide attempts in patients with MDD with comorbid dyslipidemia. The incidence of suicide attempts was similar in the early- and mid-adulthood onset subgroups among patients with MDD with dyslipidemia, but the factors associated with suicide attempts were different in these two subgroups.

Urine 3-Nitrotyrosine and Serum HDL as Potential Biomarkers of Depression

Depression (MDD) is a leading psychiatric entity worldwide, with a high impact on individual life and public health. In recent years, efforts have been made to elucidate its biological underpinnings. MDD biomarker research provides promise for a better understanding of the biochemical processes involved in its pathogenesis. Oxidative and nitrosative stress (O&NS) and lipid disturbances are reported as major factors favoring the occurrence of depression. A total of 29 patients with MDD and 30 healthy volunteers were examined using the Hamilton Depression Scale (HAM-D), the Hamilton Anxiety Scale (HAM-A), and the Beck Depression Inventory (BDI). Blood and urine were collected to search for potential MDD biomarkers. O&NS parameters and β-amyloid were assessed in the urine, while cholesterol fractions were assessed in the blood. The group of depressed patients was characterized by higher concentrations of urine superoxide dismutase (SOD), 3-nitrotyrosine (3-NT), catalase (CAT), reduced glutathione (GSH), tryptophan (TRY), and serum triglycerides (TGA), along with lower levels of serum high-density lipoprotein (HDL). Elevated urine 3-NT and decreased serum HDL, considered together, were found to have the greatest potential as markers of depression. The study supports the importance of oxidative stress and cholesterol disturbances in MDD. Further research is required to assess their clinical usefulness as markers.

Which Clinical and Biochemical Parameters Are Associated with Lifetime Suicide Attempts in Bipolar Disorder?

Introduction: Bipolar Disorder (BD) is a disabling condition with suicidal behavior as one of the most common adverse outcomes. The purpose of the present research is to investigate the relationship between lifetime suicide attempts and the clinical factors/biochemical parameters in a large sample of bipolar patients. Methods: A total of 561 patients, consecutively hospitalized for BD in Milan and Monza (Italy), were recruited. Data about the demographic and clinical variables, as well as the values of blood analyses, were collected. The groups identified according to the presence/absence of lifetime suicide attempts were compared using univariate analyses. Then, three preliminary binary logistic regressions and a final logistic regression model were performed to identify the clinical and biochemical parameters associated with lifetime suicide attempts in BD. Results: Lifetime suicide attempts in BD were predicted by a longer duration of untreated illness (DUI) (p = 0.005), absence of lifetime psychotic symptoms (p = 0.025), presence of poly-substance use disorders (p = 0.033), comorbidity with obesity (p = 0.022), a last mood episode of manic polarity (p = 0.044), and lower bilirubin serum levels (p = 0.002); higher total cholesterol serum levels showed a trend toward statistical significance (p = 0.058). Conclusions: BD patients with lifetime suicide attempts present unfavorable clinical features. Some specific biochemical characteristics of bipolar patients may represent potential markers of suicidal behavior and need to be better investigated to identify new targets of treatment in the framework of personalized medicine. These preliminary findings have to be confirmed by further studies in different clinical settings.

Effects of metabolic syndrome and obesity on suicidality in individuals with bipolar disorder

BACKGROUND

The prevalence of metabolic syndrome and overweight/obesity is increased in bipolar disorder (BD) compared to the general population and is related to suicidality. The aim of this study was to examine the association between both the rate of suicidal ideation and suicide attempts and metabolic variables in individuals with BD.

METHODS

Anthropometric measures, socio-demographic data, suicide history and serum lipid levels were measured in 215 individuals with BD. Individuals were divided into normal weight, overweight and obese according to their body mass index (BMI), and metabolic syndrome was assessed using "The International Diabetes Federation"-criteria.

RESULTS

Of the 215 individuals studied, 80.9% reported suicidal ideation, 35.3% reported at least one suicide attempt and 30.7% were diagnosed with metabolic syndrome. Both metabolic syndrome and BMI were not related to suicide attempts. However, individuals with normal weight had more suicidal ideation than overweight individuals, while obese individuals did not differ from either group. Furthermore, there was no association between suicide attempts or suicidal ideation and serum lipid levels.

LIMITATIONS

The cross-sectional design of the study, a non-standardized questionnaire for suicidality, and not controlling the medication intake are limiting factors.

CONCLUSION

Contrary to expectations, a difference was found in the BMI categories and suicidal ideation, but not suicide attempts. Serum lipid levels were found to be unsuitable as possible biomarkers for suicidality in individuals with BD. Special attention should be paid to suicidal ideation and BMI rather than metabolic syndrome or lipid values when treating suicidal individuals with BD.

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

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

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.

Possible Association of Cholesterol as a Biomarker in Suicide Behavior

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

The GSK3-NRF2 Axis in Suicide

Mutations in the genes coding for tryptophan-hydrolase-2 and the scaffold protein FKBP5 are associated with an increased risk of suicide. The mutation in both cases enhances the enzymatic activity of glycogen synthase kinase-3 (GSK3). Conversely, anti-suicidal medications, such as lithium, clozapine, and ketamine, indirectly inhibit the activity of GSK3. When GSK3 is active, it promotes the metabolic removal of the transcription factor NRF2 (nuclear factor erythroid 2-related factor-2), which suppresses the transcription of multiple genes that encode anti-oxidative and anti-inflammatory proteins. Notably, several suicide-biomarkers bear witness to an ongoing inflammatory process. Moreover, alterations in serum lipid levels measured in suicidal individuals are mirrored by data obtained in mice with genetic deletion of the NRF2 gene. Inflammation is presumably causally related to both dysphoria and anger, two factors relevant for suicide ideation and attempt. Preventing the catabolism of NRF2 could be a strategy to obtain novel suicide-prophylactic medications. Possible candidates are minocycline and nicotinic-α7 agonists. The antibiotic minocycline indirectly activates NRF2-transcriptional activity, whereas the activation of nicotinic-α7 receptors indirectly inhibits GSK3.