The association between serum lipid levels, suicide ideation, and central serotonergic activity in patients with major depressive disorder

Exploring the neurocognitive correlates of suicidal ideation in major depressive disorder: The role of frontoparietal and default mode networks

Suicidal ideation (SI) is a common symptom of major depressive disorder (MDD), often accompanied by cognitive alterations and emotional dysregulation. However, it is unclear whether cognitive dysfunction in patients with MDD is related to the presence or absence of SI and impaired connectivity within or between large-scale neurocognitive networks. Previous studies have shown that the frontoparietal network (FPN) and default mode network (DMN) are critical for cognitive control and emotional regulation. Participants were 51 MDD patients with suicidal ideation (MDDSI), 52 MDD patients without suicidal ideation (MDDNSI), and 55 healthy controls (HC). Using areas located within FPN and DMN networks as regions of interest (ROIs), we compared the cognitive performance of the three groups and the strength of the resting state functional connections (RSFC) within and between the FPN and DMN networks. Additionally, we examined the correlation between the strength of FC within the FPN and cognitive function in the SI group. Furthermore, network-based statistics (NBS) were used to correct for the strength of FPN and DMN functional connections. The study identified significant cognitive deficits in MDD patients. Reduced strength of FC was observed within the FPN and DMN networks in the SI group compared to the NSI group. In the SI group, the strength of FC within the FPN network was positively correlated with attention/vigilance. These insights underscore the critical roles of the FPN and DMN in the suicidal ideation, shedding light on the cognitively relevant neurobiological characteristics of MDDSI, providing new insights into the neural mechanisms of MDDSI. URL: https://www.chictr.org.cn/bin/project/edit?pid=131537. Registration number: ChiCTR2100049646.

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.

Differences in resting-state brain activity in first-episode drug-naïve major depressive disorder patients with and without suicidal ideation

Despite altered brain activities being associated with suicidal ideation (SI), the neural correlates of SI in major depressive disorder (MDD) have remained elusive. We enrolled 82 first-episode drug-naïve MDD patients including 41 with SI and 41 without SI, as well as 41 healthy controls (HCs). Resting-state functional and structural MRI data were collected. The measures of fractional amplitude of low-frequency fluctuation (fALFF) and grey matter volume (GMV) were calculated and compared. Compared with HCs, patients with SI exhibited increased fALFF values in the right rectus gyrus and left medial superior frontal gyrus, middle frontal gyrus and precuneus. Decreased GMV in the right parahippocampal gyrus, insula and middle occipital gyrus and increased GMV in the left superior frontal gyrus were detected in patients with SI. In addition, patients without SI demonstrated increased fALFF values in the right superior frontal gyrus and decreased fALFF values in the right postcentral gyrus. Decreased GMV in the left superior frontal gyrus, right medial superior frontal gyrus, opercular part of inferior frontal gyrus, postcentral gyrus, fusiform gyrus and increased left supplementary motor area, superior occipital gyrus, right anterior cingulate gyrus and superior temporal gyrus were revealed in patients with SI. Moreover, in comparison with patients without SI, increased fALFF values were identified in the left precuneus of patients with SI. However, no significant differences were found in GMV between patients with and without SI. These findings might be helpful for finding neuroimaging markers predicting individual suicide risk and detecting targeted brain regions for effective early interventions.

Affective disorders and the loudness dependence of the auditory evoked potential: Serotonin and beyond

Identifying additional noninvasive biomarkers for affective disorders, such as unipolar major depressive disorder (MDD) and bipolar disorder (BD), could aid in the diagnosis and treatment of these prevalent and debilitating neuropsychiatric conditions. One such candidate biomarker is the loudness dependence of the auditory evoked potential (LDAEP), an event-related potential that measures responsiveness of the auditory cortex to different intensities of sound. The LDAEP has been associated with MDD and BD, including therapeutic response to particular classes of antidepressant drugs, while also correlating with several other neuropsychiatric disorders. It has been suggested that increased values of the LDAEP indicate low central serotonergic neurotransmission, further implicating this EEG measure in depression. Here, we briefly review the literature on the LDAEP in affective disorders, including its association with serotonergic signaling, as well as with that of other neurotransmitters such as dopamine. We summarize key findings on the LDAEP and the genetics of these neurotransmitters, as well as prediction of response to particular classes of antidepressants in MDD, including SSRIs versus noradrenergic agents. The possible relationship between this EEG measure and suicidality is addressed. We also briefly analyze acute pharmacologic studies of serotonin and/or dopamine precursor depletion and the LDAEP. In conclusion, the existing literature suggests that serotonin and norepinephrine may modulate the LDAEP in an opposing manner, and that this event-related marker may be of use in predicting response to chronic treatment with particular pharmacologic agents in the context of affective disorders, such as MDD and BD, including in the presence of suicidality.

Perceived loneliness and social support in bipolar disorder: relation to suicidal ideation and attempts

BACKGROUND

The suicide rate in bipolar disorder (BD) is among the highest across all psychiatric disorders. Identifying modifiable variables that relate to suicidal thoughts and behaviors (STBs) in BD may inform prevention strategies. Social connectedness is a modifiable variable found to relate to STBs in the general population, but differences exist across subgroups of the general population and findings specifically in BD have been equivocal. We aimed to clarify how perceived social connectedness relates to STBs in BD.

METHOD

146 adults (86 BD, 60 healthy controls) completed clinical interviews (Hamilton Depression Rating Scale; Structured Clinical Interview for DSM-5) and self-report measures of loneliness (UCLA Loneliness Scale) and social support (Interpersonal Support Evaluation List). Analyses explored differences in indicators of social connectedness (loneliness and social support) between BD participants and healthy controls, and explored relationships between STBs (lifetime suicide attempts and current suicidal ideation) and indicators of social connectedness in BD participants.

RESULTS

BD participants reported significantly higher loneliness and lower social support than healthy controls. In BD participants, perceived social support was significantly related to both ever having attempted suicide and number of lifetime attempts. Interestingly, perceived loneliness, but not social support, was significantly associated with current suicidal ideation.

CONCLUSIONS

Findings expand the evidence base supporting a relationship between perceived social connectedness and STBs in BD. They suggest that this modifiable variable could be a fruitful treatment target for preventing STBs in BD.

Internet-based behavioural activation therapy versus online psychoeducation for self-reported suicidal ideation in individuals with depression in Indonesia: a secondary analysis of an RCT

BACKGROUND

Southeast Asia has the highest suicide mortality worldwide. To improve our knowledge on the effectiveness of interventions for suicidal ideation (SI) in individuals with depression in Indonesia, we conducted a secondary analysis of a randomised controlled trial.

OBJECTIVE

We explored whether an internet-based behavioural activation (BA) intervention ('Guided Act and Feel Indonesia' (GAF-ID)) was superior in targeting SI compared with online-delivered psychoeducation (PE).

METHODS

In total, 313 participants were randomised between treatment allocation. The SI item of the Patient Health Questionnaire-9 was the primary outcome measure. Mediation analyses were conducted to identify if BA at week 10 mediated the relationship between intervention and SI at week 24.

FINDINGS

The GAF-ID intervention was not superior in reducing SI compared with online minimal PE at week 10 (OR 0.61, 95% CI (0.37 to 1.01)), nor at week 24 (OR 0.84, 95% CI (0.47 to 1.52)). SI at week 24 was not mediated by BA at week 10 (b=-0.03, 95% CI (-0.05 to 0.00), p=0.07).

CONCLUSIONS

In individuals with depression in Indonesia, the GAF-ID intervention was not superior in reducing self-reported SI compared with PE. Also, the association between treatment condition and SI at week 24 was not mediated via BA at week 10.

CLINICAL IMPLICATIONS

This study supports the need for further research on the efficacy of psychological treatments targeting SI in the Southeast Asia context.

The association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) and suicidal ideation in adults: a population-based study in the United States

BACKGROUND

The ratio of non-high-density lipoprotein cholesterol (non-HDL-C) to high-density lipoprotein cholesterol (HDL-C) (NHHR) serves as a reliable lipid indicator associated with atherogenic characteristics. Studies have indicated a potential connection between suicidality and lipid metabolism. This research aims to investigate any possible association between the NHHR and the emergence of suicidal ideation within the confines of the study.

METHODS

This study examined the association between NHHR levels and suicidal ideation using data from the National Health and Nutrition Examination Survey (NHANES), conducted in the United States spanning 2005 and 2016. Calculation of the NHHR corresponds to the proportion of HDL-C to Non-HDL-C. The Patient Health Questionnaire-9's ninth question was implemented for assessing suicidal ideation. Using subgroup analysis, smooth curve fitting, and multivariate logistic regression analysis, the research was conducted.

RESULTS

Encompassing a cohort of 29,288 participants, the analysis identified that 3.82% of individuals reported suicidal ideation. After using multivariable logistic regression and thorough adjustments, elevated NHHR levels were significantly and positively associated with a heightened likelihood of suicidal ideation, according to the findings (odds ratio [OR] = 1.06; 95% confidence interval [CI]: 1.02-1.11; P = 0.0048). Despite extensive adjustment for various confounding factors, this relationship remained consistent. An inverted U-shaped curve was utilized to illustrate the link between NHHR and suicidal ideation among nonsmokers; the curve's inflection point was situated at 7.80. Subgroup analysis and interaction tests (all P for interaction > 0.05) demonstrated that there was no significant influence of the following variables on this positive relationship: age, sex, race, body mass index, education level, married status, hypertension, diabetes, and smoking status.

CONCLUSION

Significantly higher NHHR levels were associated with an elevated likelihood of suicidal ideation. Based on these results, it is probable that NHHR may serve as a predictive indicator of suicidal ideation, emphasizing its potential utility in risk assessment and preventive strategies.

The pharmacological bases for repurposing statins in depression: a review of mechanistic studies

Statins are commonly prescribed medications widely investigated for their potential actions on the brain and mental health. Pre-clinical and clinical evidence suggests that statins may play a role in the treatment of depressive disorders, but only the latter has been systematically assessed. Thus, the physiopathological mechanisms underlying statins' putative antidepressant or depressogenic effects have not been established. This review aims to gather available evidence from mechanistic studies to strengthen the pharmacological basis for repurposing statins in depression. We used a broad, well-validated search strategy over three major databases (Pubmed/MEDLINE, Embase, PsychINFO) to retrieve any mechanistic study investigating statins' effects on depression. The systematic search yielded 8068 records, which were narrowed down to 77 relevant papers. The selected studies (some dealing with more than one bodily system) described several neuropsychopharmacological (44 studies), endocrine-metabolic (17 studies), cardiovascular (6 studies) and immunological (15 studies) mechanisms potentially contributing to the effects of statins on mood. Numerous articles highlighted the beneficial effect of statins on depression, particularly through positive actions on serotonergic neurotransmission, neurogenesis and neuroplasticity, hypothalamic-pituitary axis regulation and modulation of inflammation. The role of other mechanisms, especially the association between statins, lipid metabolism and worsening of depressive symptoms, appears more controversial. Overall, most mechanistic evidence supports an antidepressant activity for statins, likely mediated by a variety of intertwined processes involving several bodily systems. Further research in this area can benefit from measuring relevant biomarkers to inform the selection of patients most likely to respond to statins' antidepressant effects while also improving our understanding of the physiopathological basis of depression.

Age-specific associations between serum cholesterol levels and suicidal behaviors in patients with depressive disorders: A naturalistic prospective observational cohort study

Introduction

This study investigated the effects of total cholesterol levels on prevalent, and incident suicidal behaviors according to age group (<60 vs. ≥60 years) in depressed patients.

Methods

Consecutive outpatients with depressive disorders who visited the Chonnam National University Hospital between March 2012 and April 2017 were recruited. Among 1,262 patients assessed at baseline, 1,094 agreed to blood sampling for measurement of serum total cholesterol levels. Among the patients, 884 completed the 12-week acute treatment phase and were followed up at least once during the 12-month continuation treatment phase. Suicidal behaviors assessed at baseline included baseline suicidal severity; behaviors assessed at the 1-year follow-up included increased suicidal severity and fatal/non-fatal suicide attempts. Associations of baseline total cholesterol levels with the above-mentioned suicidal behaviors were analyzed using logistic regression models after adjustment for relevant covariates.

Results

Of 1,094 depressed patients, 753 (68.8%) were women. The mean (SD) age of patients was 57.0 (14.9) years. Lower total cholesterol levels (87-161 mg/dl) were associated with increased suicidal severity (Linear Wald = 4.478, p < 0.05) and fatal/non-fatal suicide attempt (Linear Wald = 7.490, p < 0.01) in patients <60 years of age. U-shaped associations between total cholesterol levels and 1-year follow-up suicidal outcomes (increased suicidal severity, Quadratic Wald = 6.299, p < 0.05; fatal/non-fatal suicide attempt, Quadratic Wald = 5.697, p < 0.05) were observed in patients ≥60 years of age.

Conclusions

These findings suggest that differential consideration of serum total cholesterol levels according to age group may have clinical utility for predicting suicidality in patients with depressive disorders. However, because our research participants came from a single-hospital, the generalizability of our findings may be limited.

Temporal Stability of Dynamic Default Mode Network Connectivity Negatively Correlates with Suicidality in Major Depressive Disorder

Previous studies have demonstrated that the suicidality in patients with major depressive disorder (MDD) is related to abnormal brain functional connectivity (FC) patterns. However, little is known about its relationship with dynamic functional connectivity (dFC) based on the assumption that brain FCs fluctuate over time. Temporal stabilities of dFCs within the whole brain and nine key networks were compared between 52 MDD patients and 21 age, sex-matched healthy controls (HCs) using resting-state functional magnetic resonance imaging and temporal correlation coefficients. The alterations in MDD were further correlated with the scores of suicidality item in the Hamilton Rating Scale for Depression (HAMD). Compared with HCs, the MDD patients showed a decreased temporal stability of dFC as indicated by a significantly decreased temporal correlation coefficient at the global level, as well as within the default mode network (DMN) and subcortical network. In addition, temporal correlation coefficients of the DMN were found to be significantly negatively correlated with the HAMD suicidality item scores in MDD patients. These results suggest that MDD may be characterized by excessive temporal fluctuations of dFCs within the DMN and subcortical network, and that decreased stability of DMN connectivity may be particularly associated with the suicidality in MDD.

Altered resting-state cerebral blood flow and functional connectivity mediate suicidal ideation in major depressive disorder

The relationships among cerebral blood flow (CBF), functional connectivity (FC) and suicidal ideation (SI) in major depressive disorder (MDD) patients have remained elusive. In this study, we characterized the changes in CBF and FC among 175 individuals including 47 MDD without SI (MDDNSI), 59 MDD with SI (MDDSI), and 69 healthy control (HC) who underwent arterial spin labeling and resting-state functional MRI scans. Then the voxel-wise CBF, seed-based FC and partial correlation analyses were measured. Mediation analysis was carried out to reveal the effects of FC on the association between CBF and behavioral performances in both subgroups. Results showed that CBF was higher in MDDSI patients in the bilateral precuneus compared to HC and MDDNSI participants. MDDSI patients exhibited enhanced FC in the prefrontal-limbic system and decreased FC in the sensorimotor cortex (SMC) relative to MDDNSI patients. CBF and FC were significantly correlated with clinical variables. More importantly, exploratory mediation analyses identified that abnormal FC can mediate the association between regional CBF and behavioral performances. These results highlight the potential role of precuneus gyrus, prefrontal-limbic system as well as SMC in the process of suicide and provide new insights into the neural mechanism underlying suicide in MDD patients.

Auditory event-related potentials in separating patients with depressive disorders and non-depressed controls: A narrative review

This narrative review brings together the findings regarding the differences in the auditory event-related potentials (ERPs) between patients with depressive disorder and non-depressed control subjects. These studies' results can inform us of the possible alterations in sensory-cognitive processing in depressive disorders and the potential of using these ERPs in clinical applications. Auditory P3, mismatch negativity (MMN) and loudness dependence of auditory evoked potentials (LDAEP) were the subjects of the investigation. A search in PubMed yielded 84 studies. The findings of the reviewed studies were not highly consistent, but some patterns could be identified. For auditory P3b, the common findings were attenuated amplitude and prolonged latency among depressed patients. Regarding auditory MMN, especially the amplitude of duration deviance MMN was commonly attenuated, and the amplitude of frequency deviance MMN was increased in depressed patients. In LDAEP studies, generally, no differences between depressed patients and non-depressed controls were reported, although some group differences concerning specific depression subtypes were found. This review posits that future research should investigate whether certain stimulus conditions are particularly efficient at separating depressed and non-depressed participant groups. Future studies should contrast responses in different subpopulations of depressed patients, as well as different clinical groups (e.g., depressive disorder and anxiety disorder patients), to investigate the specificity of the auditory ERP alterations for depressive disorders.

Suicidal ideation in remitted major depressive disorder predicts recurrence

INTRODUCTION

Each year almost 800.000 people die from suicide, of which up to 87% are affected by major depressive disorder (MDD). Despite the strong association between suicidality and MDD, it remains unknown if suicidal symptoms during remission put remitted recurrent MDD patients (rrMDD) at risk for recurrence.

METHODS

At baseline we compared sociodemographic characteristics and suicidal symptoms in un-medicated rrMDD participants to matched never-depressed controls. We used the HDRS₁₇ and IDS-SR₃₀ to assess suicidal symptoms and depressive symptomatology. Next, we studied the longitudinal association between baseline suicidal symptoms and time to recurrence(s) in rrMDD during a 2.5-year follow-up period using cox regression analyses. Further, we studied with longitudinal data whether suicidal symptoms and depressive symptomatology were cross-sectionally associated using mixed model analysis.

RESULTS

At baseline, rrMDD participants (N = 73) had higher self-reported suicidal symptoms than matched never-depressed controls (N = 45) (χ² = 12.09 p < .002). Self-reported suicidal symptoms were almost four times higher (27.9% versus 6.9%) compared to clinician-rated suicidal symptoms in rrMDD at baseline. Self-reported baseline suicidal symptoms, but not clinician-rated symptoms, predicted earlier MDD-recurrence during follow-up, independent of other residual depressive symptoms (χ² = 7.26, p < .026). Higher suicidal symptoms were longitudinally related to higher depressive symptoms (HDRS₁₇; F = 49.87, p < .001), IDS-SR₃₀; (F = 22.36, p < .001).

CONCLUSION

This study showed that self-reported - but not clinician-rated - suicidal symptoms persist during remission in rrMDD and predict recurrence, independent from residual symptoms. We recommend to monitor both suicidal and depressive symptomatology during remission in rrMDD, preferably also including self-reported questionnaires apart from clinician-rated. It would be beneficial for future research to assess suicidality using questionnaires primarily designed for measuring suicidal ideation.

Inflammation and nitro-oxidative stress in current suicidal attempts and current suicidal ideation: a systematic review and meta-analysis

A meta-analysis showed a significant association between activated immune-inflammatory and nitro-oxidative (IO&NS) pathways and suicide attempts (SA). There is no data on whether recent suicidal ideation (SI) is accompanied by activated IO&NS pathways and whether there are differences between recent SA and SI. The current study searched PubMed, Google Scholar, and Web of Science, for articles published from inception until May 10, 2021, and systematically reviewed and meta-analysed the association between recent SA/SI (<3 months) and IO&NS biomarkers. We included studies which compared psychiatric patients with and without SA and SI and controls (either healthy controls or patients without SA/SI) and used meta-analysis (random-effect model with restricted maximum-likelihood) to delineate effect sizes with 95% confidence intervals (CI). Our search included 59 studies comprising 4.034 SA/SI cases and 12.377 controls. Patients with SA/SI showed activated IO&NS pathways (SMD: 0.299; CI: 0.200; 0.397) when compared to controls. The immune profiles were more strongly associated with SA than with SI, particularly when compared to healthy controls, as evidenced by activated IO&NS (SMD: 0.796; CI: 0.503; 1.089), immune (SMD: 1.409; CI: 0.637; 1.462), inflammatory (SMD: 1.200; CI: 0.584; 1.816), and neurotoxic (SMD: 0.904; CI: 0.431; 1.378) pathways. The effects sizes of the IO&NS, immune and inflammatory profiles were significantly greater in SA than in SI. In conclusion: activated IO&NS pathways are associated with recent SA and SI, and inflammation, T helper-1 activation, nitro-oxidative stress, lowered neuroprotection, and increased neurotoxicity explain at least in part why psychiatric patients show increased suicidal behaviours, especially SA.

Prevalence of suicidal ideation and planning in patients with major depressive disorder: A meta-analysis of observation studies

BACKGROUND

Suicidal ideation (SI) and suicide planning (SP) are associated with an increased risk of future suicide. We performed a meta-analysis of observational studies to estimate the prevalence of SI and SP in patients with major depressive disorder (MDD) and its associated factors.

METHODS

A systematic literature search was conducted in PubMed, EMBASE, PsycINFO and Web of Science from their commencement date until 7 October 2020. Original studies containing data on the prevalence of SI and SP in individuals with MDD were analyzed.

RESULTS

Forty-six articles covering 53,598 patients were included in the meta-analysis. The overall prevalence of SI was 37.7% (95% confidence interval (CI): 32.3-43.4%) and the pooled prevalence of SP was 15.1% (95% CI: 8.0--26.8%). Subgroup analyses revealed that the timeframe over which SI was assessed, source of patients, study design, and diagnostic criteria were significantly associated with the pooled prevalence of SI. Meta-regression analyses revealed that the Hamilton Depression Rating Scale (HAMD) score and percentage of male participants were positively associated with the pooled prevalence of SI. Study quality and mean age were negatively associated with the pooled prevalence of SI. In contrast, survey year and study quality were negatively associated with pooled prevalence of SP LIMITATION: SI and SP were self-reported and subject to recall bias and impression management.

CONCLUSIONS

SI and SP are common in patients with MDD, especially among inpatients. Preventive measures and treatments focusing on factors associated with SI and SP may reduce the risk of suicide in patients with MDD.

Statins: Neurobiological underpinnings and mechanisms in mood disorders

Statins (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors) treat dyslipidaemia and cardiovascular disease by inhibiting cholesterol biosynthesis. They also have immunomodulatory and anti-inflammatory properties. Beyond cardiovascular disease, cholesterol and inflammation appear to be components of the pathogenesis and pathophysiology of neuropsychiatric disorders. Statins may therefore afford some therapeutic benefit in mood disorders. In this paper, we review the pathophysiology of mood disorders with a focus on pharmacologically relevant pathways, using major depressive disorder and bipolar disorder as exemplars. Statins are discussed in the context of these disorders, with particular focus on the putative mechanisms involved in their anti-inflammatory and immunomodulatory effects. Recent clinical data suggest that statins may have antidepressant properties, however given their interactions with many known biological pathways, it has not been fully elucidated which of these are the major determinants of clinical outcomes in mood disorders. Moreover, it remains unclear what the appropriate dose, or appropriate patient phenotype for adjunctive treatment may be. High quality randomised control trials in concert with complementary biological investigations are needed if the potential clinical effects of statins on mood disorders, as well as their biological correlates, are to be better understood.

Lipid Profile and Impulsivity in Suicidal Patients with Major Depressive Disorder

INTRODUCTION

Previous observational cohort studies showed an association between low serum lipid levels and suicide. This study was undertaken to examine the relationship between lipid parameters and impulsivity in suicidal patients with major depressive disorder (MDD).

METHODS

The current study included 100 patients with MDD distributed as 50 patients with recent suicidal attempts and 50 patients with no lifetime history of suicide. Participants were subjected to Structured Clinical Interview for DSM-IV Axis I Disorders (SCID I) to confirm the diagnosis. The risk of suicide was assessed through the Suicide Probability Scale (SPS), while the intent and seriousness of suicide were assessed through Beck's Suicidal Intent Scale. assessment of impulsivity was carried out through Barratt Impulsivity Scale. Serum lipid levels were measured in mg/dL after an overnight fast.

RESULTS

Total cholesterol (TC) was found significantly lower in the suicidal group compared to the non-suicidal depressed group (p = 0.040). Low high-density lipoprotein (HDL) level was significantly correlated with suicidality and high suicide intent was correlated with hopelessness. Logistic regression for lipid profile in both groups revealed significant TC and low-density lipoprotein (LDL) as predictors for suicide. There was no significant correlation between impulsivity and characteristics of depression, suicide probability, suicide intent, and all elements of the lipid profile.

CONCLUSIONS

Low TC and LDL could predict suicidal behavior in patients with MDD. Impulsivity could not be a mediator or predictor of suicide risk in patients with MDD.

Increased Global-Brain Functional Connectivity Is Associated with Dyslipidemia and Cognitive Impairment in First-Episode, Drug-Naive Patients with Bipolar Disorder

Objectives

Previous researches have demonstrated that abnormal functional connectivity (FC) is associated with the pathophysiology of bipolar disorder (BD). However, inconsistent results were obtained due to different selections of regions of interest in previous researches. This study is aimed at examining voxel-wise brain-wide functional connectivity (FC) alterations in the first-episode, drug-naive patient with BD in an unbiased way.

Methods

A total of 35 patients with BD and 37 age-, sex-, and education-matched healthy controls underwent resting-state functional magnetic resonance imaging (rs-fMRI). Global-brain FC (GFC) was applied to analyze the image data. Support vector machine (SVM) was adopted to probe whether GFC abnormalities could be used to identify the patients from the controls.

Results

Patients with BD exhibited increased GFC in the left inferior frontal gyrus (LIFG), pars triangularis and left precuneus (PCu)/superior occipital gyrus (SOG). The left PCu belongs to the default mode network (DMN). Furthermore, increased GFC in the LIFG, pars triangularis was positively correlated with the triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) and negatively correlated with the scores of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) coding test and Stroop color. Increased GFC values in the left PCu/SOG can be applied to discriminate patients from controls with preferable sensitivity (80.00%), specificity (75.68%), and accuracy (77.78%).

Conclusions

This study found increased GFC in the brain regions of DMN; LIFG, pars triangularis; and LSOG, which was associated with dyslipidemia and cognitive impairment in patients with BD. Moreover, increased GFC values in the left PCu/SOG may be utilized as a potential biomarker to differentiate patients with BD from controls.

An Open-label Trial of Adjuvant High-frequency Left Prefrontal Repetitive Transcranial Magnetic Stimulation for Treating Suicidal Ideation in Adolescents and Adults With Depression

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) offers promise for the treatment of depression, yet its potential impact on suicidal ideation (SI), particularly in adolescents, has not been well studied. This study aimed to investigate the efficacy of add-on rTMS for reducing SI in a large clinical sample experiencing an acute phase of depression.

METHODS

This study included 146 patients with a score of ≥14 on the 17-item Hamilton Rating Scale for Depression (HAMD). Among them, 97 had a HAMD-SI (3-item) score of 1 or greater and were pooled into the analysis. Symptoms of depression and SI were measured using the HAMD total score and HAMD-SI score. Comparisons of clinical improvement for both SI and rates of remission were made between adolescent (n = 29) and adult patients (n = 68), as well as between high-frequency (HF) rTMS on the left dorsolateral prefrontal cortex (DLPFC) (80 trains, 30 pulses per train, 12 s intertrain interval, 2400 pulses per session) and low-frequency (LF) rTMS on the right DLPFC protocol (2 trains, 700 pulses per train, 1 s intertrain-interval, 1400 pulses per session), power (intensity) level of 120% of motor threshold (MT), and 5 sessions per week for 2 weeks.

RESULTS

Add-on rTMS treatment showed significant clinical improvement in SI, and was also well tolerated, with no adverse events reported. The SI improvements and remission rates were more significant in adolescents treated with the HF left DLPFC rTMS protocol, compared with adults treated with the LF right DLPFC rTMS protocol (remission rates: adolescent with LF right DLPFC, 50%; adolescent with HF left DLPFC, 94%; adult with LF right DLPFC, 65%; adult with HF left DLPFC, 57%). A positive association between improvement in the HAMD total score and HAMD-SI score was found in adults, but not in adolescents.

CONCLUSIONS

Add-on rTMS treatment for SI associated with depression is promising with respect to safety and feasibility. Our preliminary evidence supports an extension of the application of rTMS to adolescent patients with SI during the acute phase of depression, in addition to its use in adult treatment-resistant depression.

Relationship Between the Loudness Dependence of the Auditory Evoked Potential and the Severity of Suicidal Ideation in Patients with Major Depressive Disorder

Objective

The loudness dependence of the auditory evoked potential (LDAEP) is a reliable indicator that is inversely related to central serotonergic activity, and recent studies have suggested an association between LDAEP and suicidal ideation. This study investigated differences in LDAEP between patients with major depressive disorder and high suicidality and those with major depressive disorder and low suicidality compared to healthy controls.

Methods

This study included 67 participants: 23 patients with major depressive disorder with high suicidality (9 males, mean age 29.3 ± 15.7 years, total score of SSI-BECK ≥ 15), 22 patients with major depressive disorder with low suicidality (9 males, mean age 42.2 ± 14.4 years, total score of SSI-BECK ≤ 14), and 22 healthy controls (11 males, mean age 31.6 ± 8.7 years). Participants completed the following assessments: Patient Health Questionnaire-9, Beck Depression Inventory-II, Beck Scale for Suicidal ideation, State Anxiety Scale of the State-Trait Anxiety Inventory, Beck Anxiety Inventory, and LDAEP (measured at electrode Cz).

Results

There were no sex-related differences among groups (p = 0.821). The high-suicidality group exhibited significantly higher LDAEP compared to the low-suicidality group (0.82 ± 0.79 vs. 0.26 ± 0.36, p = 0.014). No significant differences were found between the control and high-suicidality (p = 0.281) or the control and low-suicidality groups (p = 0.236).

Conclusion

LDAEP was applied to demonstrate the association between serotonergic activity and suicidal ideation and suicide risk in major depression and may be a candidate of biological marker for preventing suicide in this study.

Are Lipids Possible Markers of Suicide Behaviors?

Suicides and suicidal behaviors are very important causes of mortality and morbidity and have become a serious global problem. More than 800,000 people die from suicide every year. Previous researches have established that lipids play an important role in the pathogenesis of suicide. Moreover, lipid levels might be a biological marker of suicide. A lot of researchers have tried to identify biological markers that might be related to depressive disorder, bipolar disorder or schizophrenia and suicidal behavior. It was also important to consider the usefulness of an additional tool for prevention actions. Metabolic deregulation, particularly low total cholesterol and low-density lipoproteins-cholesterol levels may cause higher suicide risk in patients with these psychiatric disorders.

Associations among serum markers of inflammation, life stress and suicide risk in patients with major depressive disorder

BACKGROUND

Patients with major depressive disorder (MDD) are at high risk for suicide. As the worst outcome of MDD and common self-concealment in patients with suicide risk, studies of biomarkers may provide useful tools for suicide prevention and treatment.

METHODS

This study recruited 168 patients with MDD from the Objective Diagnostic Markers and Personalized Intervention in MDD patients (ODMPIM), including 50 patients with suicide risk. Based on previous evidence and hypothesis, 23 targeted serum biomarkers involving immune-inflammation, neurotrophins, hypothalamic-pituitary-adrenal (HPA) axis and metabolism, were measured. We used path analysis and principal components analysis (PCA) to clarify the associations among serum biomarkers, childhood adversities, adulthood life events, severity of depression and suicide risk.

RESULTS

We identified that patients with suicide risk had a higher level of inflammatory markers in serum than patients without suicide risk (P < 0.001), especially chemokine (C-X-C motif) ligand 1 (CXCL-1). After using the Bonferroni correction, there were no differences in biomarkers related to neurotrophins, HPA-axis and metabolism. In addition, a higher proportion of patients with suicide risk had adulthood adversity (assessed by Life Events Scale) (P = 0.003). Intriguingly, path analysis demonstrated that the association between adulthood adversity and suicide risk mainly depended on severity of depression and inflammatory index.

CONCLUSION

This study highlights the possible role of inflammation involved in suicide risk of MDD patients. Inflammatory markers have the potential for early identification and then reducing suicidal behaviors or becoming novel treatment targets in suicide risk management.

Nutritional assessments in pregnancy and the risk of postpartum depression in Chinese women: A case-control study

Prevalence of postpartum depression (PD) in Chinese women is rising and its associated factors are not well known. In this study we aim to explore the associations between nutritional factors in pregnancy and the risk of PD in Chinese women.A case-control study was performed in our hospital during January 2016 to June 2019. A food frequency questionnaire was designed to collect food consumption before the childbirth preceding month. Nutrition related biochemical indicators including fasting blood-glucose (GLU), total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), and uric acid in the third trimester of pregnancy were detected. Logistic regression model was applied to compute odds ratio (OR) and its corresponding 95% confidence interval (CI).There were 565 participants in this study, which comprised 182 individuals with PD and 383 individuals without. Patients with PD had higher odds of increased GLU (OR=2.62, 95%CI = 1.67-4.11), TC (OR = 1.73 95%CI = 1.22-2.46), TG (OR = 2.43, 95%CI = 1.55-3.81), and LDL (OR = 3.41, 95%CI = 2.09-5.57), but decreased HDL (OR = 3.41, 95%CI = 2.09-5.57) during pregnancy. With respect to uric acid, there was lack of no statistical association (OR = 2.23, 95%CI = 0.82-6.26). Food frequency questionnaire indicated a higher meat intake, but a lower vegetable, fruit, fish, and poultry intake in patients with PD during pregnancy.Increased GLU, TC, TG, and LDL, but decreased HDL in later stages of pregnancy might be associated with PD.

Examining the underpinnings of loudness dependence of auditory evoked potentials with positron emission tomography

Loudness dependence of auditory evoked potentials (LDAEP) has long been considered to reflect central basal serotonin transmission. However, the relationship between LDAEP and individual serotonin receptors and transporters has not been fully explored in humans and may involve other neurotransmitter systems. To examine LDAEP's relationship with the serotonin system, we performed PET using serotonin-1A (5-HT_1A) imaging via [¹¹C]CUMI-101 and serotonin transporter (5-HTT) imaging via [¹¹C]DASB on a mixed sample of healthy controls (n ​= ​4: 4 females, 0 males), patients with unipolar (MDD, n ​= ​11: 4 females, 7 males) and bipolar depression (BD, n ​= ​8: 4 females, 4 males). On these same participants, we also performed electroencephalography (EEG) within a week of PET scanning, using 1000 ​Hz tones of varying intensity to evoke LDAEP. We then evaluated the relationship between LDAEP and 5-HT_1A or 5-HTT binding in both the raphe (5-HT_1A)/midbrain (5-HTT) areas and in the temporal cortex. We found that LDAEP was significantly correlated with 5-HT_1A positively and with 5-HTT negatively in the temporal cortex (p ​< ​0.05), but not correlated with either in midbrain or raphe. In males only, exploratory analysis showed multiple regions in which LDAEP significantly correlated with 5-HT_1A throughout the brain; we did not find this with 5-HTT. This multimodal study partially validates preclinical models of a serotonergic influence on LDAEP. Replication in larger samples is necessary to further clarify our understanding of the role of serotonin in perception of auditory tones.

The prevalence, metabolic disturbances and clinical correlates of recent suicide attempts in Chinese inpatients with major depressive disorder

BACKGROUND

Metabolic disturbances have been correlated with suicidality, but little is known about the association between suicide risk and metabolic disturbances among individuals with depression. This study was to evaluate the prevalence and clinical correlations, especially cardio-metabolic associated factors of recent suicide attempts in Chinese patients with major depressive disorder (MDD).

METHODS

A total of 288 MDD inpatients were recruited. Their clinical and demographic data together with plasma glucose, lipid and thyroid function parameters were collected. Self-Rating Depression Scale (SDS), Self-Rating Anxiety Scale (SAS) and Eysenck Personality Questionnaire (EPQ) were rated for most of the patients.

RESULTS

Of these MDD inpatients, 20.14% had attempted suicide during the past 1 month. Compared to those who had not attempted suicide, the suicide attempters had a significantly longer duration of illness, lower low-density lipoprotein (LDL) cholesterol, lower total cholesterol, and more psychotic symptoms. However, all these significant results did not survive after the bonferroni correction (all p > 0.05). A logistic regression analysis indicated that suicide attempts were associated with the lower total cholesterol and more psychotic symptoms.

CONCLUSIONS

Our findings support the hypothesis of the association of low plasma cholesterol level and recent suicidal attempts in patients with MDD.

Serum lipids and brain-derived neurotrophic factor in a cross-section of male students with symptoms of depression at a university in Iran: an observational study

Background

Depression is a neuroprogressive disorder that is characterized by neurotransmitter derangement and decreased neurogenesis and neurotrophic factors including brain-derived neurotrophic factor (BDNF).

Objectives

To determine the lipid profiles and BDNF levels in university students at an institution in Iran and association of these factors with Beck Depression Inventory (BDI) scores.

Methods

We conducted an observational study of a cross-section of male students at the Ahvaz Jundishapur University of Medical Sciences in Iran. For each of the 100 participants, a BDI score was obtained and serum levels of BDNF were measured by enzyme-linked immunosorbent assay. Levels of serum lipids, including cholesterol, triglycerides, low-density lipoprotein (LDL), and high-density lipoprotein (HDL), were measured using a biochemical analyzer. Castelli’s risk index type I (CRI-I), Castelli’s risk index type II (CRI-II), CRI-I = TG/HDL-C and CRI-II = LDL-cholesterol/ HDL-cholesterol, and atherogenic index of plasma (AIP), AIP = log (triglycerides/HDL-cholesterol), were calculated.

Results

Based on BDI scores, lower levels of BDNF, triglycerides, cholesterol, and HDL, but higher levels of LDL were found in participants with higher BDI scores. CRI-I was also increased in participants with depression.

Conclusion

The levels of BDNF and lipid factors are associated with the severity of depression in Iranian male university students. Deranged levels of BDNF and lipids may predispose depressed students to cardiovascular diseases.

Hypocholesterolemia is an independent risk factor for depression disorder and suicide attempt in Northern Mexican population

BACKGROUND

Cholesterol has been associated as a risk factor for cardiovascular disease. Recently, however, there is growing evidence about crucial requirement of neuron membrane cholesterol in the organization and function of the 5-HT_1A serotonin receptor. For this, low cholesterol level has been reported to be associated with depression and suicidality. However there have been inconsistent reports about this finding and the exact relationship between these factors remains controversial. Therefore, we investigated the link between serum cholesterol and its fractions with depression disorder and suicide attempt in 467 adult subjects in Mexican mestizo population.

METHODS

Plasma levels of total cholesterol, triglycerides, and high-density lipoprotein cholesterol (HDL-c) and low density lipoprotein cholesterol (LDL-c) were determined in 261 MDD patients meeting the DSM-5 criteria for major depressive disorder (MDD), 59 of whom had undergone an episode of suicide attempt, and 206 healthy controls.

RESULTS

A significant decrease in total cholesterol, LDL-cholesterol, VLDL-cholesterol and triglyceride serum levels was observed in the groups of MDD patients and suicide attempt compared to those without suicidal behavior (p < 0.05). After adjusting for covariates, lower cholesterol levels were significantly associated with MDD (OR 4.229 CI 95% 2.555 - 7.000, p<.001) and suicide attempt (OR 5.540 CI 95% 2.825 - 10.866, p<.001) CONCLUSIONS: These results support the hypothesis that lower levels of cholesterol are associated with mood disorders like MDD and suicidal behavior. More mechanistic studies are needed to further explain this association.

Association between cognitive deficits and suicidal ideation in patients with major depressive disorder

The role of cognitive function in suicidal ideation in patients with major depressive disorder (MDD) has not been adequately explored. This research sought to measure the relationship between suicidal ideation and cognitive function. Therefore, in this study, the association between cognitive function and suicidal ideation in patients with MDD was assessed. Cognitive function was evaluated in 233 patients with MDD using the Japanese version of the Brief Assessment of Cognition in Schizophrenia (BACS). Suicidal ideation was assessed using item 3 of the Hamilton Depression Rating Scale. Approximately 59.2% of the patients (138/233) expressed suicidal ideation. Among the BACS subtests, only the executive function scores were significantly lower in patients with MDD with than in those without (p < 0.005). In addition, the executive function, motor speed function, and composite scores correlated negatively with the severity of suicidal ideation in these patients. These results suggest that executive function, motor speed function, and global neuropsychological function are associated with suicidal ideation in patients with MDD and that the BACS neuropsychological battery is an efficient instrument for monitoring these characteristics. Moreover, specific BACS scores can potentially serve as cognitive biomarkers of suicide risk in patients with MDD.

Lipids, lipoprotein distribution and depressive symptoms: the Multi-Ethnic Study of Atherosclerosis

Previous studies suggest lower concentrations of total and high-density lipoprotein (HDL) cholesterol to be predictive of depression. We therefore investigated the relationship of lipids and lipoprotein distribution with elevated depressive symptoms (EDS) in healthy men and women from the Multi-Ethnic Study of Atherosclerosis (MESA). Participants were followed up over a 9.5-year period. EDS were defined as a Center for Epidemiological Studies Depression (CES-D) score ⩾16 and/or use of antidepressant drugs. Lipoprotein distribution was determined from plasma using nuclear magnetic resonance spectroscopy. Among 4938 MESA participants (mean age=62 years) without EDS at baseline, 1178 (23.9%) developed EDS during follow-up. In multivariable Cox regression analyses, lower total, low-density lipoprotein (LDL) and non-HDL cholesterol concentrations at baseline were associated with incident EDS over 9.5 years (hazards ratio (HR)=1.11-1.12 per s.d. decrease, all P<0.01), after adjusting for demographic factors, traditional risk factors including LDL cholesterol, HDL cholesterol and triglycerides. Lipoprotein particle subclasses and sizes were not associated with incident EDS. Among participants without EDS at both baseline and visit 3, a smaller increase in total or non-HDL cholesterol between these visits was associated with lower risk of incident EDS after visit 3 (HR=0.88-0.90 per s.d. decrease, P<0.05). Lower baseline concentrations of total, LDL and non-HDL cholesterol were significantly associated with a higher risk of incident EDS. However, a short-term increase in cholesterol concentrations did not help to reduce the risk of EDS. Further studies are needed to replicate our findings in cohorts with younger participants.

The Prevalence and Predictors of Depression in Type 2 Diabetic Population of Punjab

The present cross sectional study was carried out on 787 type 2 diabetic subjects from tertiary health care hospitals to identify the prevalence and predictors of depression in diabetes. Depression was tested using Patient Health Questionnaire-9. Of the study participants, 199 (25.29%) met the criteria for mild to moderate depression, 252 (32.02%) were severely depressed and 336 (42.69%) were clinically non-depressed. The prevalence of depression was 65.02 % in women, which is 1.87 fold higher (p < 0.0001) than men (49.87%). Depression was observed to be strongly associated with advancing age >30 years (p < 0.05), low income (p = 0.0001), sedentary life style (p = 0.001), Plasma levels of low density lipoproteins (LDL) >100 mg/dl and triglycerides (TG) >150 mg/dl (p < 0.05), drinking alcohol (p < 0.001), statin use (p < 0.001), BMI >35-39.9 kg m(-2) (p = 0.018), WHR >0.9 cm (p < 0.0001), Glucose levels >125 mg/dl (p < 0.0001) and duration of diabetes 2-4 years (p = 0.003). In multivariate logistic regression model, risk factors such as, being a woman, duration of diabetes ≥10 years, BMI ≥30 kg m(-2), LDL >100 mg/dl, TG >150 mg/dl and sedentary life style emerged as independent predictors of depression in diabetes. In the present study, 86.4 % diabetic subjects were not diagnosed for depression prior participation. In conclusion, the present study revealed that higher prevalence of depression in diabetes was evident in population of Punjab, especially in women and majority of these patients remain undiagnosed for depression.

Clinical predictor and circulating microRNA profile expression in patients with early onset post-stroke depression

OBJECTIVE

We aim to explore the clinical factors and blood biomarker for predicting the early-onset post-stroke depression (PSD).

METHODS

251 acute ischemic stroke patients were divided into PSD group and non-PSD group by Hamilton depression scale in 2 weeks after stroke. The clinical data, the severity, etiology and location of stroke were recorded. The analysis of inflammatory mediator, glycose and lipid metabolism was performed on the day of admission. The association between clinical factors and early onset PSD was studied by logistic regression analysis. In addition, the differentially expressed miRNAs in plasma between the two groups were screened by gene chip and the bio-information was further investigated by GO and KEEG analysis.

RESULTS

Among 251 patients, 45 (17.93%) were diagnosed as early onset PSD. NIHSS score (>3) and carotid stenosis were independent relative factors with early-onset PSD (OR 3.479 and 2.617, p=0.000 and 0.009, respectively). Moreover, lower LDL trended toward association with early onset PSD in minor stroke subgroup (p=0.084). MiRNA profile demonstrated 25 differential expressed circulating miRNAs with FC≥2 and P≤0.05 between the two groups. The target genes of these miRNAs were enriched in pathways of cancer and MAPK signaling.

LIMITATIONS

The sample of the study was small. The results should be further confirmed in large cohort patients.

CONCLUSIONS

Early onset PSD was more likely in patients with severe neurological deficits and carotid artery stenosis, also note the possible association between lower LDL and depression in minor stroke. Blood miRNAs may be served as a potential biomarker for PSD diagnosis.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

[Biological basis of suicidal behavior]

Based on current clinical and classification concepts of suicidality, the biological parameters characteristic of suicidal behavior, completed and uncompleted suicides reported in the last few decades are discussed. The results obtained in the studies of neurotransmitter and other brain systems, immune system, lipid and other types of metabolism as well as data of neuroimaging brain studies and post-mortem investigation of brain structures are presented.

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.

Influence of the 5-HT3A Receptor Gene Polymorphism and Childhood Sexual Trauma on Central Serotonin Activity

Background

Gene-environment interactions are important for understanding alterations in human brain function. The loudness dependence of auditory evoked potential (LDAEP) is known to reflect central serotonergic activity. Single nucleotide polymorphisms (SNPs) in the 5-HT3A serotonin receptor gene are associated with psychiatric disorders. This study aimed to investigate the effect between 5-HT3A receptor gene polymorphisms and childhood sexual trauma on the LDAEP as an electrophysiological marker in healthy subjects.

Methods

A total of 206 healthy subjects were recruited and evaluated using the childhood trauma questionnaire (CTQ) and hospital anxiety and depression scale (HADS). Peak-to-peak N1/P2 was measured at five stimulus intensities, and the LDAEP was calculated as the linear-regression slope. In addition, the rs1062613 SNPs of 5-HT3A (CC, CT, and TT) were analyzed in healthy subjects.

Results

There was a significant interaction between scores on the CTQ-sexual abuse subscale and 5-HT3A genotype on the LDAEP. Subjects with the CC polymorphism had a significantly higher LDEAP than T carriers in the sexually abused group. In addition, CC genotype subjects in the sexually abused group showed a significantly higher LDAEP compared with CC genotype subjects in the non-sexually abused group.

Conclusions

Our findings suggest that people with the CC polymorphism of the 5-HT3A gene have a greater risk of developing mental health problems if they have experienced childhood sexual abuse, possibly due to low central serotonin activity. Conversely, the T polymorphism may be protective against any central serotonergic changes following childhood sexual trauma.

The Loudness Dependence of Auditory Evoked Potentials (LDAEP) in individuals at risk for developing bipolar disorders and schizophrenia

OBJECTIVES

The Loudness Dependence of Auditory Evoked Potentials (LDAEP) is considered as an indicator of central serotonergic activity. Alteration of serotonergic neurotransmission was reported in bipolar disorders and schizophrenia. In line with previous reports on clinically manifest disorders, we expected a weaker LDAEP in subjects at risk for bipolar disorders and schizophrenia compared to healthy controls.

METHODS

We analyzed LDAEP of individuals at risk for developing bipolar disorders (n=27), with high-risk status (n=74) and ultra-high-risk status for schizophrenia (n=86) and healthy controls (n=47).

RESULTS

The LDAEP did not differ between subjects at risk for schizophrenia or bipolar disorders and controls. Among subjects without medication (n=122), the at-risk-bipolar group showed a trend towards a weaker LDAEP than both the high-risk and the ultra-high-risk groups for schizophrenia.

CONCLUSIONS

The LDAEP did not appear as a vulnerability marker for schizophrenia or bipolar disorders. This suggests that an altered LDAEP may not be measurable until the onset of clinically manifest disorder. However, the hypothesis that pathogenic mechanisms leading to bipolar disorders may differ from those leading to schizophrenia is supported.

SIGNIFICANCE

This is the first study investigating LDAEP in a population at risk for bipolar disorders.

Relationship between Serotonergic Dysfunction Based on Loudness Dependence of Auditory-Evoked Potentials and Suicide in Patients with Major Depressive Disorder

The relationship between suicidality and the loudness dependence of auditory-evoked potentials (LDAEP) remains controversial. This article reviews the literature related to the LDAEP and suicide in patients with major depressive disorder, and suggests future research directions. Serotonergic dysfunction in suicidality seems to be more complicated than was originally thought. Studies of suicide based on the LDAEP have produced controversial results, but it is possible that these are due to differences in study designs and the smallness of samples. For example, some studies have evaluated suicide ideation and the LDAEP, while others have evaluated suicide attempts and the LDAEP. Furthermore, some of the latter studies enrolled acute suicide attempters, while others enrolled those with the history of previous suicide attempts, irrespective of whether these were acute or chronic. Thus, a more robust study design is needed in future studies, for example by evaluating the LDAEP immediately after a suicide attempt rather than in those with a history of suicide attempts and suicide ideation in order to reduce bias. Moreover, genuine suicide attempt, self-injurious behaviors, and faked suicide attempt need to be discriminated in the future.

Suicidal ideation is associated with reduced prefrontal activation during a verbal fluency task in patients with major depressive disorder

BACKGROUND

Despite the known relationship between prefrontal function and increased suicidality during major depressive episodes, the links between prefrontal function and suicidality remain unclear in major depressive disorder (MDD). Suicidal ideation usually precedes a suicide attempt. If prefrontal cortex (PFC) activity is a biomarker for suicidal ideation in depression, monitoring it could be useful for suicide prevention. Therefore, in this study, we assessed the association between prefrontal function and suicidal ideation in MDD.

METHODS

Prefrontal function in 67 patients with MDD (31 with suicidal ideation and 36 without) and 67 age-, gender-, and intelligence quotient-matched healthy controls (HCs) was evaluated using near-infrared spectroscopy (NIRS) during a verbal fluency task (VFT). Suicidal ideation was assessed using item 3 of the Hamilton Depression Rating Scale (HAMD).

RESULTS

Regional hemodynamic changes were significantly smaller in patients with MDD than in HCs in prefrontal and temporal regions. Hemodynamic changes in the right dorsolateral PFC (DLPFC), orbitofrontal cortex (OFC), and right frontopolar cortex (FPC) regions in patients with MDD with suicidal ideation were significantly smaller than in those without suicidal ideation. In addition, hemodynamic changes correlated negatively with the severity of suicidal ideation in the DLPFC, OFC, and FPC in patients with MDD.

LIMITATIONS

Further studies with a larger sample size are required to verify our findings.

CONCLUSIONS

These results suggest that the DLPFC, OFC, and FPC are brain substrates of suicidal ideation in depressive states in patients with MDD, and that NIRS data can be employed as a clinically useful biomarker for the assessment of suicide risk.

The use of statins for the treatment of depression in patients with acute coronary syndrome

This study aimed to investigate the effect of statins for the treatment of depression in individuals with acute coronary syndrome (ACS). We used 1-year follow-up data of a 24-week double-blind, placebo-controlled trial of escitalopram and a naturalistic prospective observational cohort study. Of 446 participants with comorbid depressive disorders and ACS at baseline, 300 participated in a randomised escitalopram trial and the remaining 146 participated in a naturalistic observational study. The participants in the two studies were approached for a 1-year follow-up investigation. Treatment response rates, defined as a ⩾ 50% reduction in the Hamilton Depression Rating Scale (HAM-D) and Beck Depression Inventory (BDI) scores, were used as the outcome variables. In the escitalopram trial, both HAM-D and BDI response rates were highest in patients taking escitalopram and statins together and lowest in patients receiving neither medication. Logistic regression analyses revealed that statin use was significantly associated with higher response rates on both the HAM-D and BDI at 1 year, whereas no such associations were found for escitalopram. In the naturalistic observational study, the response rates at 1 year did not differ significantly by statin use. Instead, the HAM-D response rate was significantly higher in patients taking lipophilic statins than in those who did not. In conclusion, statins may be effective for the treatment of depression independent of medical status and escitalopram use, and they may potentiate the antidepressant action of serotonergic antidepressants in patients with ACS.

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.

Potential neurochemical links between cholesterol and suicidal behavior

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

Alteration in the expression of exon IIC transcripts of brain-derived neurotrophic factor gene by simvastatin [correction of simvastain] in chronic mild stress in mice: a possible link with dopaminergic pathway

We have investigated the influence of dopaminergic agents on the expression of brain-derived neurotrophic factor (BDNF) gene in relation with lipid levels in chronic mild stress (CMS). Mice subjected to CMS were treated with simvastatin (10 mg/kg, per os (orally)) along with bromocriptine (2 mg/kg, intraperitoneally (ip)), levodopa (200 mg/kg, ip), or haloperidol (0.1 mg/kg, ip) for 14 days. CMS produced a decrease in sucrose intake and an increase in serum cholesterol and triglycerides levels with a decrease in high-density lipoprotein cholesterol, which were prevented by simvastatin. This was greater when it was combined with bromocriptine or levodopa. Haloperidol significantly prevented the simvastatin-induced increase in sucrose intake but not the alterations in lipids. There was an upregulation in the expression of BDNF exon-IIA and -IIB transcripts by CMS but not the exon-IIC transcripts. Simvastatin could increase expression of exon-IIC transcripts in stressed mice. This was partially increased by bromocriptine. Haloperidol significantly prevented simvastatin-induced increase in expression of BDNF exon-IIC transcripts. The results showed a positive correlation between expression of BDNF exon-IIC transcripts and sucrose intake. In conclusion, our data suggest the involvement of lipid levels and BDNF exon-IIC transcripts in CMS-induced behaviour in mice, possibly through the dopaminergic system.

Suicidal behaviour and lipid levels in unipolar and bipolar depression

INTRODUCTION

Evidence for a possible association between a low level of cholesterol and increased suicidal behaviour has accumulated in the recent 3 decades. The present study investigates whether lipid levels can make state-dependent markers of suicidal behaviour in Polish patients with mood disorder recently admitted to a psychiatric hospital owing to an acute depressive episode.

MATERIALS AND METHODS

The study was conducted on 223 patients (73 male and 150 female) with unipolar (n=171) and bipolar (n=52) depression. They were interviewed to assess any occurrence of suicidal thoughts, suicidal tendencies and/or suicidal attempts during the 3 months before admission. Laboratory measurements [total cholesterol, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, triglycerides and total lipids] were obtained within 24-72 h after hospital admission.

RESULTS

Suicidal thoughts, tendencies, and attempts were associated with low total cholesterol, LDL cholesterol, and total lipids in both male and female patients, in both diagnostic categories. Triglycerides were significantly lower in male and female patients with suicidal thoughts compared with their non-suicidal counterparts. No association with suicidality was found with HDL cholesterol.

CONCLUSIONS

The results of our study support a majority of research showing the association in depressed patients between suicidal behaviour and low levels of total and LDL cholesterol. In addition, the data suggest a similar association with low total lipids, and in some instances, with low triglycerides.