Serum cholesterol and serotonergic function in major depressive disorder

Evaluation of the association of physical activity levels with self-perceived health, depression, and anxiety in Spanish individuals with high cholesterol levels: a retrospective cross-sectional study

Background

Hypercholesterolemia is the most common form of dyslipidaemia in the world leading to negative health effects, both physical and mental. Physical activity (PA) can reduce total cholesterol and has positive effects on mental health. This retrospective cross-sectional study analyses the relationships between physical activity level (PAL), self-perceived health (SPH) and mental health.

Methods

This study was based on data from the Spanish National Health Survey 2017 (SNHS 2017), with 3,176 Spanish adults with high cholesterol as participants. Non-parametric tests were used as the data did not follow normality.

Results

Dependent relationships were found between PAL and SPH, depression and anxiety. Women had higher depression and anxiety prevalences than men, while men were more likely to report being very active, although the proportion of walkers was higher in women. The physically inactive population presented higher negative SPH, depression and anxiety proportions and psychological distress than physically active people.

Conclusion

The physically inactive people had a higher risk of negative SPH, depression and anxiety. Regular PA may improve SPH and mental health in people with high cholesterol, but more studies are needed to establish causal relationships, mechanisms, and optimal doses.

Sex difference in association between suicide attempts and lipid profile in first-episode and drug naive patients with major depressive disorder

BACKGROUND

The relationship between suicide attempts and lipid profiles in patients with major depressive disorder (MDD) remains uncertain. The purpose of this study was to investigate sex differences in the relationship between suicide attempts and plasma lipid profiles in a large sample of first-episode and drug naive (FEDN) MDD patients.

METHODS

We recruited 1718 FEDN MDD patients and gathered demographic, clinical, and blood lipid data. The Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale and the Positive and Negative Syndrome Scale were used to assess the symptoms of patients.

RESULTS

There was no significant difference in the prevalence of suicide attempts between male and female MDD patients. The suicide attempt group had higher levels of depression, anxiety, psychotic symptoms, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C), but lower levels of high-density lipoprotein cholesterol (HDL-C) levels than the non-suicide attempt group. Binary logistic regression showed that TC levels were significantly correlated with suicidal attempts in both male and female patients. Correlation analysis revealed that the levels of TC, HDL-C and LDL-C were significantly associated with the number of suicide attempts in both male and female patients. Further multiple linear regression revealed that TC levels were significantly associated with the number of suicide attempts in male patients only.

CONCLUSIONS

Lipid biomarkers, particularly high TC levels, are associated with suicide attempts in both male and female MDD patients. However, there is gender difference in association between lipid biomarkers, especially TC levels, and the number of suicide attempts in MDD patients.

Association of non-HDL-C and depression: a cross-sectional analysis of the NHANES data

Objectives

Non-high-density lipoprotein cholesterol (non-HDL-C) has attracted attention because it is associated with a variety of diseases and is easy to measure. However, the relationship between non-HDL-C and depression is still unclear. Our aim was to assess the relationship between non-HDL-C and depression using the cross-sectional NHANES survey from 2005 to 2018.

Methods

We examined the association between non-HDL-C and depression using weighted multivariable logistic regression models and subgroup analysis. Sensitivity analysis demonstrated the robustness of the results.

Results

There were 42,143 participants in this study and 8.6% had depression (weighted 7.53%). Non-HDL-C was higher in participants with depression compared to those without depression (weighted mean 3.64 vs. 3.73, p < 0.01). There was a positive association between non-HDL-C and depression with a 95% OR of 1.22 adjusted for multifactorial (95% CI,1.03-1.45). In subgroup analyses, non-HDL-C was positively associated with depression in men (OR, 1.31; 95% CI, 1.01-1.70), normal BMI (OR: 0.93; 95% CI: 0.66-1.32) and in participants without hypertension (OR, 1.29; 95% CI, 1.01-1.66).

Conclusion

Non-HDL-C positively correlated with depression, and further research may be better for clinical service.

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.

Alterations in acylcarnitines, amines, and lipids inform about the mechanism of action of citalopram/escitalopram in major depression

Selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment for major depressive disorder (MDD), yet their mechanisms of action are not fully understood and their therapeutic benefit varies among individuals. We used a targeted metabolomics approach utilizing a panel of 180 metabolites to gain insights into mechanisms of action and response to citalopram/escitalopram. Plasma samples from 136 participants with MDD enrolled into the Mayo Pharmacogenomics Research Network Antidepressant Medication Pharmacogenomic Study (PGRN-AMPS) were profiled at baseline and after 8 weeks of treatment. After treatment, we saw increased levels of short-chain acylcarnitines and decreased levels of medium-chain and long-chain acylcarnitines, suggesting an SSRI effect on β-oxidation and mitochondrial function. Amines-including arginine, proline, and methionine sulfoxide-were upregulated while serotonin and sarcosine were downregulated, suggesting an SSRI effect on urea cycle, one-carbon metabolism, and serotonin uptake. Eighteen lipids within the phosphatidylcholine (PC aa and ae) classes were upregulated. Changes in several lipid and amine levels correlated with changes in 17-item Hamilton Rating Scale for Depression scores (HRSD₁₇). Differences in metabolic profiles at baseline and post-treatment were noted between participants who remitted (HRSD₁₇≤ 7) and those who gained no meaningful benefits (<30% reduction in HRSD₁₇). Remitters exhibited (a) higher baseline levels of C3, C5, alpha-aminoadipic acid, sarcosine, and serotonin; and (b) higher week-8 levels of PC aa C34:1, PC aa C34:2, PC aa C36:2, and PC aa C36:4. These findings suggest that mitochondrial energetics-including acylcarnitine metabolism, transport, and its link to β-oxidation-and lipid membrane remodeling may play roles in SSRI treatment response.

Cholesterol homeostasis: Researching a dialogue between the brain and peripheral tissues

Cholesterol homeostasis is a highly regulated process in human body because of its several functions underlying the biology of cell membranes, the synthesis of all steroid hormones and bile acids and the need of trafficking lipids destined to cell metabolism. In particular, it has been recognized that peripheral and central nervous system cholesterol metabolism are separated by the blood brain barrier and are regulated independently; indeed, peripherally, it depends on the balance between dietary intake and hepatic synthesis on one hand and its degradation on the other, whereas in central nervous system it is synthetized de novo to ensure brain physiology. In view of this complex metabolism and its relevant functions in mammalian, impaired levels of cholesterol can induce severe cellular dysfunction leading to metabolic, cardiovascular and neurodegenerative diseases. The aim of this review is to clarify the role of cholesterol homeostasis in health and disease highlighting new intriguing aspects of the cross talk between its central and peripheral metabolism.

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.

The Association between Depressive Mood and Cholesterol Levels in Korean Adolescents

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Serum lipidomic analysis for the discovery of biomarkers for major depressive disorder in drug-free patients

Lipidomic analysis can be used to efficiently identify hundreds of lipid molecular species in biological materials and has been recently established as an important tool for biomarker discovery in various neuropsychiatric disorders including major depressive disorder (MDD). In this study, quantitative targeted serum lipidomic profiling was performed on female subjects using liquid chromatography-mass spectrometry. Global lipid profiling of pooled serum samples from 10 patients currently with MDD (cMDD), 10 patients with remitted MDD (rMDD), and 10 healthy controls revealed 37 differentially regulated lipids (DRLs). DRLs were further verified using multiple-reaction monitoring (MRM) in each of the 25 samples from the three groups of independent cohorts. Using multivariate analysis and MRM data we identified serum biomarker panels of discriminatory lipids that differentiated between pairs of groups: lysophosphatidic acid (LPA)(16:1), triglycerides (TG)(44:0), and TG(54:8) distinguished cMDD from controls with 76% accuracy; lysophosphatidylcholines(16:1), TG(44:0), TG(46:0), and TG(50:1) distinguished between cMDD and rMDD at 65% accuracy; and LPA(16:1), TG(52:6), TG(54:8), and TG(58:10) distinguished between rMDD and controls with 60% accuracy. Our lipidomic analysis identified peripheral lipid signatures of MDD, which thereby provides providing important biomarker candidates for MDD.

HDL-cholesterol concentrations are inversely associated with Edinburgh Postnatal Depression Scale scores during pregnancy: results from a Brazilian cohort study

Serum lipids have been associated with depression in the adult population; however, this association during pregnancy remains unclear. The aim of this study was to evaluate the association between serum lipids and depressive symptom scores during pregnancy. A prospective cohort of 238 pregnant women was followed at the 5th-13th, 20th-26th and 30th-36th weeks of gestation. Depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale (EPDS). Serum concentrations (mg/dL) of triglycerides, total cholesterol, and low- and high-density lipoproteins (LDL-c; HDL-c) were the main exposures. Marital status (married/single), physical activity (active or very active/low or very low active), unplanned pregnancy (no/yes), pre-pregnancy BMI (<25/≥ 25 kg/m(2)), generalized anxiety disorder (no/yes) and current suicidal ideation (no/yes) were considered as potential confounders. Analyses were performed using linear mixed-effects models. The results showed that the EPDS mean score (95%CI) decreased with time during pregnancy trimesters [1st: 8.89 (95%CI = 8.28-9.51), 2nd: 7.32 (95%CI = 6.67-7.97) and 3rd: 7.08 (95%CI = 6.41-7.74)]. Suicidal ideation frequency at baseline was 18%. HDL-c concentrations were inversely associated with changes in EPDS score (β = -0.080, 95%CI = -0.157 to -0.002), while low or very low active women (β = 1.288, 95%CI = 0.630-1.946), with single marital status (β = 1.348, 95%CI = 0.163-2.534), unplanned pregnancy (β = 1.922, 95%CI = 0.714-3.131), generalized anxiety disorder (β = 2.139, 95%CI = 0.410-3.868) and current suicidal ideation (β = 1.927, 95%CI = 0.596-3.258) tended to have higher EPDS scores. No relationship was observed between other lipids and EPDS scores. HDL-c concentration was inversely associated with changes in depressive symptom scores during pregnancy after adjusting for socio-economic, demographic, behavioral, nutritional, biochemical and mental health disorders.

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.

No association between serum cholesterol and death by suicide in patients with schizophrenia, bipolar affective disorder, or major depressive disorder

Background

Previous research on serum total cholesterol and suicidality has yielded conflicting results. Several studies have reported a link between low serum total cholesterol and suicidality, whereas others have failed to replicate these findings, particularly in patients with major affective disorders. These discordant findings may reflect the fact that studies often do not distinguish between patients with bipolar and unipolar depression; moreover, definitions and classification schemes for suicide attempts in the literature vary widely.

Methods

Subjects were patients with one of the three major psychiatric disorders commonly associated with suicide: schizophrenia, bipolar affective disorder, and major depressive disorder (MDD). We compared serum lipid levels in patients who died by suicide (82 schizophrenia, 23 bipolar affective disorder, and 67 MDD) and non-suicide controls (200 schizophrenia, 49 bipolar affective disorder, and 175 MDD).

Results

Serum lipid profiles did not differ between patients who died by suicide and control patients in any diagnostic group.

Conclusions

Our results do not support the use of biological indicators such as serum total cholesterol to predict suicide risk among patients with a major psychiatric disorder.

Ziprasidone with adjunctive mood stabilizer in the maintenance treatment of bipolar I disorder: long-term changes in weight and metabolic profiles

This analysis was conducted to compare the effects of adjunctive ziprasidone or placebo on metabolic parameters among patients receiving maintenance treatment with lithium or valproate. We also tested whether metabolic syndrome (MetS) and other risk factors were associated with baseline characteristics and treatment response. In the stabilization phase (Phase 1), 584 bipolar I disorder (DSM-IV) patients received 2.5-4 months of open label ziprasidone (80-160 mg/d) plus lithium or valproic acid (ZIP+MS). Patients who achieved at least 8 weeks of clinical stability were subsequently randomized into Phase 2 to 6-months of double-blind treatment with ZIP+MS (n=127) vs. placebo+MS (n=113). At baseline of Phase 1, MetS was found in 111 participants (23%). Participants with MetS (vs. non-MetS participants) were more likely to be aged 40 years or older, had significantly more severe manic symptoms, higher abdominal obesity, and higher BMI. Increase in abdominal obesity was associated with lower manic symptom improvement (p<0.05, as assessed by MRS change score) during Phase 1, while symptom improvement differed across racial groups. In the Phase 2 double-blind phase, the ZIP+MS group had similar weight and metabolic profiles compared to the placebo+MS group across visits. These results corroborate existing findings on ziprasidone which exhibits a neutral weight and metabolic profile in the treatment of schizophrenia and bipolar patients. Our findings suggest that MetS is highly prevalent in patients with bipolar disorder, may be associated with greater manic symptom severity, and may predict treatment outcomes.

Thrombocyte serotonin and serum cholesterol concentration in suicidal and non-suicidal depressed patients

INTRODUCTION

Numerous studies have confirmed the connection of reduced serum cholesterol and thrombocyte serotonin concentration with suicidal behavior in psychiatric patients. The purpose of such studies was to determine the link among cholesterol and serotonin concentration, comparing depressed patients with and without attempted suicide with phenotypically healthy control group.

MATERIALS AND METHODS

The examinees' groups consisted of 55 depressed patients with suicide attempt and 77 depressed patients with no suicide attempt. In accordance to ICD-10, the above patients were separated in two subgroups; F32.2 and F33.2. Phenotypically healthy control group was presented by the group of healthy blood donors. The fasting serum cholesterol concentration was established using standard enzymatic method, while the thrombocyte serotonin concentration was determined by the enzymatic immune-chemical method (ELISA).

RESULTS

The ANOVA test (N=228, F(ratio)=8.26, p<0.001) found significant difference of cholesterol concentration between groups, with lowest concentration in depressed patients with attempted suicide (SNK post hoc test, p<0.05). Upon gender stratification, the significance remained for the female patients (ANOVA, N=125, F(ratio)=6.06, p=0.003). The serum cholesterol was shown to be statistically lower in the group of depressed patients with attempted suicide, diagnoses F32.2 (p=0.031) and F33.2 (p=0.011), compared to the group of depressed patients without attempted suicides. The thrombocyte serotonin was found to be significantly different in all examined groups, with the lowest thrombocyte serotonin in the group of depressed patients with no suicide attempt (SNK post hoc test, p<0.05, N=187, F(ratio)=37.69, p<0.001). The same significance was found for the group of female (ANOVA, N=103, F(ratio)=11.81, p<0.001) and the group of male patients (ANOVA, N=84, F(ratio)=30.40, p<0.001). The thrombocyte serotonin was significantly lower in the group of depressed patients with no suicide attempt (F32.2), compared to the same diagnosis in the group of depressed patients with suicide attempt (MW-test, p=0.018).

CONCLUSION

In the group of depressed patients with attempted suicide, statistically significant lower serum cholesterol values have been confirmed. In the group of depressed patients with no suicide attempt, statistically significant lower values of thrombocyte serotonin have been confirmed, presumably as the response to the psychopharmacological therapy.

[Electroencephalographic examination of the cerebral activity of elderly people living in a nursing home after postural change from supine to sitting positions]

AIM

We investigated the cerebral activity of elderly persons living in a nursing home in the sitting position by analyzing the electroencephalography findings of postural changes in the supine and sitting positions.

METHODS

This study was approved by the Health Ethics Committee of Osaka University. The subjects were 17 elderly people (4 men and 13 women, average age 85.35 ± 8.26 years) living in a nursing home. Electroencephalograms were obtained in 8 cerebral regions (the left front-polar (Fp(1)); right front-polar (Fp(2)); left frontal (F(3)); right frontal (F(4)); left central (C(3)); right central (C(4)); left occipital (O(1)) and right occipital (O(2))) while subjects sat in a head-up position in bed, or in a chair or wheelchair. Measurement was obtained over 5-minute supine, 15-minute sitting, and 5-minute conversation periods. We performed the fast Fourier transform on measured electroencephalograms to calculate the average power values of alpha band components (8-13 Hz) and beta band components (13-30 Hz) for each cerebral section.

RESULTS

Compared with the supine position, the sitting position in bed did not show a significant increase in power values, whereas the sitting position in a chair showed significant increases in power values in all regions. Most of the time, the findings of patients sitting position in a chair showed significantly higher power values than those of patients sitting in bed in all regions.

CONCLUSIONS

During the 20 minutes after postural change from the supine to sitting positions, the cerebral activity of subjects sitting in a chair was higher than that of subjects sitting in bed.

Cholesterol and CSF 5-HIAA in attempted suicide

BACKGROUND

Low serum cholesterol has been linked to suicide and violent behaviour. The same kind of associations has been reported regarding low levels of 5-hydroxyindolacetic acid (5-HIAA) in the cerebrospinal fluid (CSF) and suicidal behaviour. The hypothesis of the link between serum cholesterol and suicide incorporate serotonin. It proposes that low cholesterol is related to altered serotonergic neurotransmission. A correlation between CSF 5-HIAA and serum cholesterol has been shown in animal studies, but has not been found in humans.

AIM

To study the interrelationship between serum cholesterol and CSF 5-HIAA in suicide attempters. Since both cholesterol and CSF 5-HIAA are associated with suicide and violent suicide attempts, we also investigated the correlation with suicide, violent suicide attempt method, suicide intent, hopelessness and depression severity.

METHODS

Serum total cholesterol and CSF 5-HIAA were measured in 42 medication free suicide attempters. Patients were assessed with Becks's Hopelessness scale (BHS), Suicide Intent Scale (SIS) and Montgomery-Asberg depression rating scale (MADRS) and followed-up for causes of death.

RESULTS

Serum total cholesterol and CSF 5-HIAA showed a significant positive correlation adjusted for age, body mass index and substance abuse diagnosis. Cholesterol and CSF 5-HIAA levels did not differ between violent and non-violent suicide attempters or between suicide completers and survivors.

CONCLUSIONS

These findings indicate that the serotonergic system may be connected to serum cholesterol in patients with a recent suicide attempt.

Cholesterol and affective morbidity

Depression and mania have been linked with low cholesterol though there has been limited prospective study of cholesterol and subsequent course of affective illness. We studied the relationship between fasting total cholesterol and subsequent depressive and manic symptoms. A total of 131 participants from a prospective cohort study were identified as having had a fasting total cholesterol evaluation at intake. Participants were predominantly inpatients at index visit and were followed for a median of 20 and up to 25 years. Cholesterol was modeled with age, gender, and index use of a mood stabilizer in linear regression to assess its influence on subsequent depressive symptom burden in participants with unipolar disorder as well as depressive and manic symptom burden in participants with bipolar disorder. Among bipolar participants (N=65), low cholesterol predicted a higher proportion of follow-up weeks with manic, but not depressive symptoms. Cholesterol did not appear to predict depressive symptom burden among participants with unipolar depression (N=66). Lower cholesterol levels may predispose individuals with bipolar disorder to a greater burden of manic symptomatology and may provide some insight into the underlying neurobiology.

Lovastatin potentiates the antidepressant efficacy of fluoxetine in rats

BACKGROUND

Cholesterol may have a role in the pathophysiology of depression. Lowering cholesterol levels with statins reduces risks for cardiovascular events, and there is clinical evidence that statins exert neuroprotective properties not fully explained by their effects on serum cholesterol levels. Altered cholesterol levels can affect serotonergic neurotransmission, which might be involved in the clinical efficacy of standard antidepressants.

METHODS

We examined interactions between a statin (lovastatin) and a selective serotonin reuptake inhibitor (fluoxetine) using the forced swim test (FST) in rats, a behavioral assay that identifies treatments with antidepressant effects in humans. Specifically, we determined if the addition of lovastatin to the diet would increase the efficacy of a subeffective dose of fluoxetine.

RESULTS

Rats maintained on a lovastatin-enriched diet for 30 days were more sensitive to the antidepressant-like effects of a low (subthreshold) dose of fluoxetine. The behavior of rats treated with this combination resembled that normally seen with higher doses of fluoxetine. No effects were observed in rats maintained on a lovastatin-enriched diet for 3 days.

CONCLUSIONS

Lovastatin can augment the antidepressant-like effects of a low dose of fluoxetine in rats, raising the possibility that statins could be used to facilitate the effects of antidepressants in humans.

Behavioral effects of dietary cholesterol in rats tested in experimental models of mild stress and cognition tasks

Abnormalities in serum cholesterol levels of patients with mood disorders have been identified in epidemiological studies. However, evidence for an influence of dietary cholesterol on behavioral models is poor. Here, we investigated the behavioral changes of Wistar male rats fed a 2% cholesterol-enriched diet for 2 months in experimental models of depression and anxiety, such as the forced swim test (FST) paradigm and the novelty-induced grooming sampling test (NGT). The correlation between behavioral depression and impaired cognitive capacity was also examined testing rats in the Morris water maze (MWM) task one day after the FST. Different groups of rats fed various dietary regimens, were subjected to acute or repeated treatment (14 days) with clomipramine hydrochloride (50 or 25 mg/kg), diazepam (1 mg/kg) or with the peripheral benzodiazepine receptors (PBRs) antagonist, isoquinoline PK11195 (1 mg/kg) injected intraperitoneally (i.p.). Rats fed the cholesterol-enriched diet showed a significant decrease of grooming score in the NGT and of immobility time in the FST in comparison to animals fed a standard diet. Furthermore, the anxiolytic and antidepressant effects of diazepam and clomipramine were not affected by the different diets. Only after repeated treatment, PK11195 impaired the performance of animals fed a standard diet in the FST, and exhibited an anxiolytic-like profile in animals fed either the cholesterol-enriched or the standard diet. The improved performance in the FST was followed by a better learning performance in the acquisition phase of the MWM. These results suggest that effects of cholesterol-enriched diet on the behavioral reaction of rats in experimental models of mild stress may involve PBRs. They deserve attention in order to clarify the clinical correlation between plasma cholesterol levels and mood disorders in humans.

Serotonin transporter protein in pulmonary hypertensive rats treated with atorvastatin

HMG-CoA-reductase inhibitors (statins) influence lipid metabolism and have pleiotropic effects. Several statins reduce various forms of pulmonary hypertension (PH) in animal models. The relationship between atorvastatin and expression of serotonin transporter protein (5-HTT) remains unknown. This study focused on the effects of atorvastatin on the course of monocrotaline (MCT)-induced PH and its relation to 5-HTT expression. Male Sprague-Dawley rats were challenged with MCT with or without subsequent daily oral treatment with 0.1, 1, and 10 mg/kg of atorvastatin for 28 days. Over the 4-wk course, the progression of PH was followed by transthoracic echocardiography [pulmonary artery pressure was assessed by pulmonary artery flow acceleration time (PAAT), an estimate reciprocal to pulmonary artery pressure], and, at the end of the 4-wk course, invasive right ventricular pressure, right ventricular weight, quantitative morphology, and 5-HTT expression were measured. MCT caused significant PH as early as 7 days after injection. Atorvastatin treatment increased PAAT and reduced right ventricular pressure, right ventricular hypertrophy, and vascular remodeling over the 4-wk course. MCT challenge was associated with increased pulmonary vascular 5-HTT expression, and atorvastatin treatment reduced the 5-HTT expression. MCT-induced PH over the course of 4 wk can be easily followed by transthoracic echocardiography, and atorvastatin is effective in reducing the PH. Atorvastatin's effects are associated with a decrease of 5-HTT expression.

Low plasma cholesterol levels in suicidal males: a gender- and body mass index-matched case-control study of suicide attempters and nonattempters

Findings from animal and human studies suggest an association between low cholesterol levels and suicidal behaviors. The purpose of this case-control study was to test whether cholesterol levels in suicide attempters are lower than in controls without suicide attempt history matched by gender, age, and body mass index (BMI). Suicide attempters (n=177: 68 men and 109 women) and controls (177 blood donors) were assessed. Serum cholesterol levels were significantly lower in suicide attempters than in controls. After gender stratification, the difference remained significant in men, but not in women.

Changes in platelet monoamine oxidase activity, cholesterol levels and hyperactive behaviour in adolescents over a period of three years

Platelet monoamine oxidase (MAO) activity is a peripheral marker of central serotonergic activity, and has been associated with aggressive, impulsive and hyperactive behaviour, alcohol and drug abuse. Central serotonergic activity has also been associated with plasma cholesterol levels. In the present longitudinal investigation in adolescents (n = 320) changes in platelet MAO activity and in plasma cholesterol levels over three years were measured, and their possible association with changes in aggressive and hyperactive behaviour, smoking, alcohol and drug use was studied. The measures were taken at age 15 and 18 years. Psychological data were obtained from teachers by using the Hyperactivity Scale [B. af Klinteberg, Studies on Sex-related Psychological and Biological Indicators of Psychosocial Vulnerability: A Developmental Perspective, University of Stockholm, Department of Psychology, 1988]. The results of the study show that in most of the tested individuals, platelet MAO activity is a relatively stable measure, however, there was a significant number of subjects with a noticeable change in MAO activity. In subjects with decreased platelet MAO activity, total and HDL cholesterol levels were significantly increased. Also, changes in HDL cholesterol and in platelet MAO activity were inversely associated with changes in the score of Concentration Difficulties. The changes in platelet MAO activity and cholesterol level were not associated with alcohol and drug use among the subjects. This longitudinal analysis provides preliminary evidence that changes in platelet MAO activity and cholesterol, which may reflect changes in central serotonergic activity are associated with attention deficit in adolescents.

Cholesterol-lowering therapy evokes time-limited changes in serotonergic transmission

A number of studies have reported an increased risk for violent deaths and depression in subjects with reduced serum cholesterol concentrations. Links with hypothesized impairment of serotonin neurotransmission have not been satisfactorily tested. In this investigation, the serum and membrane cholesterol, microviscosity of erythrocyte membranes, platelet serotonin uptake, and clinical parameters were determined during pharmacotherapy of 17 hypercholesterolemic patients. A significant decrease in serum cholesterol and a nonsignificant decrease in membrane cholesterol concentration were found after 2 months of simvastatin therapy. Serotonin transporter (SERT) activity was significantly increased following 1 month of simvastatin; the tendency to decrease the initial increase in SERT activity was evident following 2 months of therapy. Both membrane cholesterol and SERT activity returned to pre-treatment levels after more than 1 year of therapy. Microviscosity of plasma membranes, impulsivity, empathy, adventure, sensation seeking, and depressed mood were not markedly changed. These data indicate that long-term therapy has different effects on serotonin transmission from short-term (1- to 2-month) therapy. A significant increase in SERT activity was detected only during the first month of simvastatin therapy. This finding suggests that within this period some patients could be vulnerable to depression, violence, or suicide.

Geriatric depression and vascular diseases: what are the links?

BACKGROUND

The term "vascular depression" has been proposed to describe a subset of depressive disorders that occurs in old age as a consequence of cerebrovascular disease. However, depression has been shown to result from other cardiovascular diseases such as coronary heart diseases, as well as to precipitate, worsen or precede vascular diseases. Depression also increases the likelihood of the incidence of vascular risk factors such as diabetes.

AIMS

To review clinical and epidemiological evidence linking geriatric depression and vascular diseases, and to discuss the potential mechanisms that could underlie this association.

METHOD

Systematic review of the literature of the last 5 years through Medline database search.

RESULTS

Papers report the following potential ways of association: (1) there is a direct influence of vascular disease, in particular, arteriosclerosis, on the incidence of depression; (2) depressive disorders have a direct impact on the cardiovascular system; (3) depression and vascular disease share either a common pathophysiological process or genetic determinants.

DISCUSSION

Depression can be understood as the direct consequence of brain damage in neurodegenerative disorders such as Parkinson's or Huntington's diseases. Similarly, vascular depression is mostly considered to be the consequence of microvascular lesions on prefrontal and subcortical regions. However, this functional neuroanatomical model offers no explanation for cases where depression has been shown to precede vascular diseases. Since cardiovascular diseases develop in a context of acquired environmental factors together with genetically determined disease, it may be postulated that geriatric depression could both result from brain lesions of vascular origin and also share some pathogenic or genetic determinants.

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

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

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

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