Statins in Depression: An Evidence-Based Overview of Mechanisms and Clinical Studies

Associations between C-reactive protein and individual symptoms of depression in a lower-middle income country

BACKGROUND

Data on associations between inflammation and depressive symptoms largely originate from high income population settings, despite the greatest disease burden in major depressive disorder being attributed to populations in lower-middle income countries (LMICs).

AIMS

We assessed the prevalence of low-grade inflammation in adults with treatment-resistant depression (TRD) in Pakistan, an LMIC, and investigated associations between peripheral C-reactive protein (CRP) levels and depressive symptoms.

METHOD

This is a secondary analysis of two randomised controlled trials investigating adjunctive immunomodulatory agents (minocycline and simvastatin) for Pakistani adults with TRD (n = 191). Logistic regression models were built to assess the relationship between pre-treatment CRP (≥ or <3 mg/L) and individual depressive symptoms measured using the Hamilton Depression Rating Scale. Descriptive statistics and regression were used to assess treatment response for inflammation-associated symptoms.

RESULTS

High plasma CRP (≥3 mg/L) was detected in 87% (n = 146) of participants. Early night insomnia (odds ratio 2.33, 95% CI 1.16-5.25), early morning waking (odds ratio 2.65, 95% CI 1.29-6.38) and psychic anxiety (odds ratio 3.79, 95% CI 1.39-21.7) were positively associated, while gastrointestinal (odds ratio 0.38, 95% CI 0.14-0.86) and general somatic symptoms (odds ratio 0.34, 95% CI 0.14-0.74) were negatively associated with inflammation. Minocycline, but not simvastatin, improved symptoms positively associated with inflammation.

CONCLUSIONS

The prevalence of inflammation in this LMIC sample with TRD was higher than that reported in high income countries. Insomnia and anxiety symptoms may represent possible targets for personalised treatment with immunomodulatory agents in people with elevated CRP. These findings require replication in independent clinical samples.

Association of statin use with risk of depression and anxiety: A prospective large cohort study

OBJECTIVES

To examine associations between regular statin use and the incidence of depression and anxiety.

METHODS

This cohort was based on UK Biobank participants without depression/anxiety recruited between 2006 and 2010. The self-reported regular statin use was collected at baseline. Depression and anxiety outcomes were assessed by diagnostic interviews (international classification of diseases codes) and nondiagnostic scales (mental well-being questionnaires). Cox proportional hazards models adjusted for a wide range of confounders were used to estimate associations of statins with incident depression/anxiety.

RESULTS

Among 363,551 eligible participants, 55,838 reported regular statin use. During a 13-year follow-up, 14,765 cases of depression and 15,494 cases of anxiety were identified. Compared with non-statin users, statin use was associated with reduced risk of depression (hazard ratio [HR]: 0.87; 95% confidence interval [CI]: 0.81, 0.94) and anxiety (HR: 0.90, 95% CI: 0.84, 0.97). Effects of statins on depression were consistent in sensitivity analyses and may be less influenced by unmeasured confounders. However, results of online survey data showed that statin use might not be associated with incident anxiety (HR: 0.96, 95% CI: 0.85, 1.09).

CONCLUSION

Regular statin use was associated with a lower risk of depression. No clear associations between statin use and anxiety were found.

"Inflamed" depression: A review of the interactions between depression and inflammation and current anti-inflammatory strategies for depression

Depression is a common mental disorder, the effective treatment of which remains a challenging issue worldwide. The clinical pathogenesis of depression has been deeply explored, leading to the formulation of various pathogenic hypotheses. Among these, the monoamine neurotransmitter hypothesis holds a prominent position, yet it has significant limitations as more than one-third of patients do not respond to conventional treatments targeting monoamine transmission disturbances. Over the past few decades, a growing body of research has highlighted the link between inflammation and depression as a potential key factor in the pathophysiology of depression. In this review, we first summarize the relationship between inflammation and depression, with a focus on the pathophysiological changes mediated by inflammation in depression. The mechanisms linking inflammation to depression as well as multiple anti-inflammatory strategies are also discussed, and their efficacy and safety are assessed. This review broadens the perspective on specific aspects of using anti-inflammatory strategies for treating depression, laying the groundwork for advancing precision medicine for individuals suffering from "inflamed" depression.

One Molecule, Many Faces: Repositioning Cardiovascular Agents for Advanced Wound Healing

Chronic wound treatments pose a challenge for healthcare worldwide, particularly for the people in developed countries. Chronic wounds significantly impair quality of life, especially among the elderly. Current research is devoted to novel approaches to wound care by repositioning cardiovascular agents for topical wound treatment. The emerging field of medicinal products' repurposing, which involves redirecting existing pharmaceuticals to new therapeutic uses, is a promising strategy. Recent studies suggest that medicinal products such as sartans, beta-blockers, and statins have unexplored potential, exhibiting multifaceted pharmacological properties that extend beyond their primary indications. The purpose of this review is to analyze the current state of knowledge on the repositioning of cardiovascular agents' use and their molecular mechanisms in the context of wound healing.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

FINDINGS

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

CONCLUSIONS

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

CLINICAL IMPLICATIONS

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

Lipid-Lowering Medications are Associated with Reduced Sarcopenia-Related Quality of Life in Older Adults with Hyperlipidemia

PURPOSE

Statins medications negatively affect age-associated loss of muscle mass and strength, termed sarcopenia, and neuromuscular junction (NMJ) integrity. However, their association with the sarcopenia-related-quality-of-life (SarQoL) is unknown.

METHODS

In this cross-sectional, case control study, we recruited male nonusers (n = 75 and age 75.2 ± 5.9 years) and users (n = 77 and age 77.1 ± 6.2 years) of statins to evaluate SarQoL and handgrip strength (HGS). We also measured plasma C-terminal agrin fragment-22 (CAF22) as a marker of NMJ degradation.

RESULTS

Statin users had higher CAF22, and lower HGS, and cumulative SarQoL scores than non-users (all p < 0.05). Plasma CAF22 exhibited negative correlations with SarQoL scores for physical and mental health, locomotion, functionality, activities-of-daily-living, and cumulative SarQoL in statins users and non-users (all p < 0.05). Lastly, the cumulative SarQoL scores exhibited positive associations with HGS and gait speed in the study participants (all p < 0.05).

CONCLUSIONS

Collectively, statin usage was associated with NMJ degradation and reduced SarQoL. Statins should be cautiously prescribed in patients with sarcopenia with reduced QoL.

Characteristics of clinical-pharmacological recommendations in psychiatry in Germany

OBJECTIVE

Psychiatric patients in general, and elderly psychiatric patients in particular, are at risk of adverse drug reactions due to comorbidities and inappropriate polypharmacy. Interdisciplinary and clinical-pharmacologist-led medication reviews may contribute to medication safety in the field of psychiatry. In this study, we reported the frequency and characteristics of clinical-pharmacological recommendations in psychiatry, with a particular focus on geriatric psychiatry.

METHOD

A clinical pharmacologist, in collaboration with the attending psychiatrists and a consulting neurologist, conducted interdisciplinary medication reviews in a general psychiatric ward with a geropsychiatric focus at a university hospital over a 25-week period. All clinical and pharmacological recommendations were recorded and evaluated.

RESULTS

A total of 316 recommendations were made during 374 medication reviews. Indications/contraindications of drugs were the most frequently discussed topics (59/316; 18.7 %), followed by dose reductions (37/316; 11.7 %), and temporary or permanent discontinuation of medications (36/316; 11.4 %). The most frequent recommendations for dose reduction involvedbenzodiazepines (9/37; 24.3 %). An unclear or absent indication was the most common reason for recommending temporary or permanent discontinuation of the medication (6/36; 16.7 %).

CONCLUSION

Interdisciplinary clinical pharmacologist-led medication reviews represented a valuable contribution to medication management in psychiatric patients, particularly the elderly ones.

Pretreatment with Lovastatin Improves Depression-Like Behavior After Traumatic Brain Injury Through Activation of the AMPK Pathway

BACKGROUND

The beneficial effect of pretreatment with statins on traumatic brain injury (TBI)-induced depression and anxiety and its mechanism of action remain unclear. In this study, we combined epidemiological and experimental animal data to clarify this issue.

METHODS

We used the Taiwan National Health Insurance database to identify patients who were diagnosed with TBI from 2000 to 2013 and compared patients with and without statin treatment matched by age, sex, and underlying comorbidities in a 1:1 ratio. The risk of developing depression and/or anxiety was compared between patients with and without a statin using Cox proportional hazards regression. We also used a rat model to assess the effect of lovastatin pretreatment on neurobehavioral and neuropathological changes following TBI.

RESULTS

The risk of developing depression was lower in the 41,803 patients in the statin cohort than nonstatin cohort (adjusted hazard ratio, 0.91 [95% confidence interval, 0.83-0.99]). In animal models, the lovastatin group had significantly reduced infarct volume, decreased immobility time and latency to eat, a reduced number of Fluoro- Jade-positive cells and levels of glial fibrillary acidic protein and tumor necrosis factor-alpha, and increased adenosine monophosphate -activated protein kinase (AMPK) and its upstream kinase liver kinase B1 in the hippocampal dentate gyrus. These effects were blocked in AMPK inhibitor-pretreated TBI rats.

CONCLUSIONS

Our epidemiological data showed that a decreased risk of depression was associated with statin pretreatment, which was supported by an animal study. The underlying mechanism for this appears to involve AMPK activation in the statin pretreatment-induced alleviation of TBI.

Statin for mood and inflammation among adult patients with major depressive disorder: an updated meta-analysis

Introduction

Several small sample-sized clinical trials have demonstrated a beneficial effect of statin on depressive mood among major depressive disorder (MDD) patients. However, observational studies have showed the increased risk of anxiety/depression with statin treatment. Therefore, we aimed to evaluate the effects of statin on depressive mood and inflammation status among MDD patients.

Methods

We performed an updated meta-analysis RCTs identified in systematic searches of PubMed, Cochrane library, Embase, ClinicalTrials.gov, CNKI, Wan fang, VIP, and SinoMed database (up to August 2023). The primary endpoint was the Hamilton depression rating scale (HDRS). The secondary endpoints were rate of response to treatment, remission rate, levels of C-reactive protein (CRP), cognition and blood lipid. We evaluated the certainty of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

Results

The search identified seven RCTs involving 448 patients with a median follow-up of 10.4 weeks (range, 6-12 weeks). Compared with selective serotonin reuptake inhibitors (SSRIs) alone, treatment with statin plus SSRIs was associated with a significantly decreased HDRS [mean difference (MD) = -2.79; 95% confidence interval (CI): -3.83 to -1.76] and C-reactive protein (MD = -0.42 mg/L; 95% CI: -0.53 to -0.12 mg/L), and decreased levels of lipid profiles (P < 0.05). Moreover, statin plus SSRIs was associated with a comparable rate of treatment response [relative risk (RR) = 1.26; 95% CI: 0.98 to 1.62], remission rate (RR = 1.33; 95% CI: 0.89 to 1.99). Meta-regression indicated that the follow-up period was a source of heterogeneity regarding the HDRS (r = 0.302, P = 0.041). The quality of evidence was rated as moderate for HDRS and response rate according to the GRADE.

Conclusion

Statin could safely and effectively improve the symptoms of depression and inflammation status among MDD patients.

Systematic review registration

https://inplasy.com/inplasy-2022-3-0016/, identifier INPLASY2022230016.

Real-world outcomes of concomitant antidepressant and statin use in primary care patients with depression: a population-based cohort study

BACKGROUND

Antidepressants are licensed for use in depressive disorders, but non-response and poor adherence to treatment affect a considerable number of patients. Pre-clinical and clinical evidence suggest that statins can augment the effects of antidepressants. However, the acceptability and tolerability of combining statins with antidepressants are unclear, and their add-on efficacy has only been shown in small, short-term clinical trials. Observational data can provide complementary information about treatment effects on larger samples over longer follow-ups. In this study, we therefore assessed the real-world acceptability, tolerability, and efficacy of concomitant antidepressant and statin treatment in depression.

METHODS

We conducted a population-based cohort study investigating QResearch primary care research database, which comprises the anonymised electronic healthcare records of 35 + million patients over 1574 English general practices. Patients aged 18-100 years, registered between January 1998 and August 2020, diagnosed with a new episode of depression, and commencing an antidepressant were included. Using a between-subject design, we identified two study groups: antidepressant + statin versus antidepressant-only prescriptions. Outcomes of interest included the following: antidepressant treatment discontinuations due to any cause (acceptability) and due to any adverse event (tolerability) and effects on depressive symptoms (efficacy) measured as response, remission, and change in depression score on the Patient Health Questionnaire-9. All outcomes were assessed at 2, 6, and 12 months using multivariable regression analyses, adjusted for relevant confounders, to calculate adjusted odds ratios (aORs) or mean differences (aMDs) with 99% confidence intervals (99% CIs).

RESULTS

Compared to antidepressant-only (N 626,335), antidepressant + statin (N 46,482) was associated with higher antidepressant treatment acceptability (aOR2months 0.88, 99% CI 0.85 to 0.91; aOR6months 0.81, 99% CI 0.79 to 0.84; aOR12months 0.78, 99% CI 0.75 to 0.81) and tolerability (aOR2months 0.92, 99% CI 0.87 to 0.98; aOR6months 0.94, 99% CI 0.89 to 0.99, though not long term aOR12 months 1.02, 99% CI 0.97 to 1.06). Efficacy did not differ between groups (range aOR2-12 months 1.00 and 1.02 for response and remission, range aOR2-12 months - 0.01 and - 0.02 for change in depression score).

CONCLUSIONS

On real-world data, there is a positive correlation between antidepressant treatment adherence and statin use, partly explained by fewer dropouts due to adverse events. The main limitation of our study is its observational design, which restricts the potential to make causal inferences.

Comorbidity between major depressive disorder and physical diseases: a comprehensive review of epidemiology, mechanisms and management

Populations with common physical diseases - such as cardiovascular diseases, cancer and neurodegenerative disorders - experience substantially higher rates of major depressive disorder (MDD) than the general population. On the other hand, people living with MDD have a greater risk for many physical diseases. This high level of comorbidity is associated with worse outcomes, reduced adherence to treatment, increased mortality, and greater health care utilization and costs. Comorbidity can also result in a range of clinical challenges, such as a more complicated therapeutic alliance, issues pertaining to adaptive health behaviors, drug-drug interactions and adverse events induced by medications used for physical and mental disorders. Potential explanations for the high prevalence of the above comorbidity involve shared genetic and biological pathways. These latter include inflammation, the gut microbiome, mitochondrial function and energy metabolism, hypothalamic-pituitary-adrenal axis dysregulation, and brain structure and function. Furthermore, MDD and physical diseases have in common several antecedents related to social factors (e.g., socioeconomic status), lifestyle variables (e.g., physical activity, diet, sleep), and stressful live events (e.g., childhood trauma). Pharmacotherapies and psychotherapies are effective treatments for comorbid MDD, and the introduction of lifestyle interventions as well as collaborative care models and digital technologies provide promising strategies for improving management. This paper aims to provide a detailed overview of the epidemiology of the comorbidity of MDD and specific physical diseases, including prevalence and bidirectional risk; of shared biological pathways potentially implicated in the pathogenesis of MDD and common physical diseases; of socio-environmental factors that serve as both shared risk and protective factors; and of management of MDD and physical diseases, including prevention and treatment. We conclude with future directions and emerging research related to optimal care of people with comorbid MDD and physical diseases.

Major depressive disorder

Major depressive disorder (MDD) is characterized by persistent depressed mood, loss of interest or pleasure in previously enjoyable activities, recurrent thoughts of death, and physical and cognitive symptoms. People with MDD can have reduced quality of life owing to the disorder itself as well as related medical comorbidities, social factors, and impaired functional outcomes. MDD is a complex disorder that cannot be fully explained by any one single established biological or environmental pathway. Instead, MDD seems to be caused by a combination of genetic, environmental, psychological and biological factors. Treatment for MDD commonly involves pharmacological therapy with antidepressant medications, psychotherapy or a combination of both. In people with severe and/or treatment-resistant MDD, other biological therapies, such as electroconvulsive therapy, may also be offered.

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.

An online experimental medicine trial on the effect of 28-day simvastatin administration on emotional processing, reward learning, working memory and salivary cortisol in healthy volunteers at risk for depression: OxSTEP protocol

BACKGROUND

Evidence suggests inflammation may be a key mechanism by which psychosocial stress, including loneliness, predisposes to depression. Observational and clinical studies have suggested simvastatin, with its anti-inflammatory properties, may have a potential use in the treatment of depression. Previous experimental medicine trials investigating 7-day use of statins showed conflicting results, with simvastatin displaying a more positive effect on emotional processing compared with atorvastatin. It is possible that statins require longer administration in predisposed individuals before showing the expected positive effects on emotional processing.

AIMS

Here, we aim to test the neuropsychological effects of 28-day simvastatin administration versus placebo, in healthy volunteers at risk for depression owing to loneliness.

METHOD

This is a remote experimental medicine study. One hundred participants across the UK will be recruited and randomised to either 28-day 20 mg simvastatin or placebo in a double-blind fashion. Before and after administration, participants will complete an online testing session involving tasks of emotional processing and reward learning, processes related to vulnerability to depression. Working memory will also be assessed and waking salivary cortisol samples will be collected. The primary outcome will be accuracy in identifying emotions in a facial expression recognition task, comparing the two groups across time.

Investigating the potential anti-depressive mechanisms of statins: a transcriptomic and Mendelian randomization analysis

Observational studies and randomized controlled trials presented inconsistent findings on the effects of cholesterol-lowering statins on depression. It therefore remains unclear whether statins have any beneficial effects on depression, and if so, what the underlying molecular mechanisms are. Here, we aimed to use genomic approaches to investigate this further. Using Connectivity Map (CMap), we first investigated whether statins and antidepressants shared pharmacological effects by interrogating gene expression responses to drug exposure in human cell lines. Second, using Mendelian randomization analysis, we investigated both on-target (through HMGCR inhibition) and potential off-target (through ITGAL and HDAC2 inhibition) causal effects of statins on depression risk and depressive symptoms, and traits related to the shared biological pathways identified from CMap analysis. Compounds inducing highly similar gene expression responses to statins in HA1E cells (indicated by an average connectivity score with statins > 90) were found to be enriched for antidepressants (12 out of 38 antidepressants; p = 9E-08). Genes perturbed in the same direction by both statins and antidepressants were significantly enriched for diverse cellular and metabolic pathways, and various immune activation, development and response processes. MR analysis did not identify any significant associations between statin exposure and depression risk or symptoms after multiple testing correction. However, genetically proxied HMGCR inhibition was strongly associated with alterations in platelets (a prominent serotonin reservoir) and monocyte percentage, which have previously been implicated in depression. Genetically proxied ITGAL inhibition was strongly associated with basophil, monocyte and neutrophil counts. We identified biological pathways that are commonly perturbed by both statins and antidepressants, and haematological biomarkers genetically associated with statin targets. Our findings warrant pre-clinical investigation of the causal role of these shared pathways in depression and potential as therapeutic targets, and investigation of whether blood biomarkers may be important considerations in clinical trials investigating effects of statins on depression.

Therapy of traumatic brain injury by modern agents and traditional Chinese medicine

Traumatic brain injury (TBI) is the leading cause of disability and death, and the social burden of mortality and morbidity caused by TBI is significant. Under the influence of comprehensive factors, such as social environment, lifestyle, and employment type, the incidence of TBI continues to increase annually. Current pharmacotherapy of TBI mainly focuses on symptomatic supportive treatment, aiming to reduce intracranial pressure, ease pain, alleviate irritability, and fight infection. In this study, we summarized numerous studies covering the use of neuroprotective agents in different animal models and clinical trials after TBI. However, we found that no drug has been approved as specifically effective for the treatment of TBI. Effective therapeutic strategies for TBI remain an urgent need, and attention is turning toward traditional Chinese medicine. We analyzed the reasons why existing high-profile drugs had failed to show clinical benefits and offered our views on the research of traditional herbal medicine for treating TBI.

Effect of Adjunctive Simvastatin on Depressive Symptoms Among Adults With Treatment-Resistant Depression: A Randomized Clinical Trial

Importance

Immune-metabolic disturbances have been implicated in the pathophysiology of major depressive disorder and may be more prominent in individuals with treatment-resistant depression (TRD). Preliminary trials suggest that lipid-lowering agents, including statins, may be useful adjunctive treatments for major depressive disorder. However, no adequately powered clinical trials have assessed the antidepressant efficacy of these agents in TRD.

Objective

To assess the efficacy and tolerability of adjunctive simvastatin compared with placebo for reduction of depressive symptoms in TRD.

Design, Setting, and Participants

This 12-week, double-blind, placebo-controlled randomized clinical trial was conducted in 5 centers in Pakistan. The study involved adults (aged 18-75 years) with a Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) major depressive episode that had failed to respond to at least 2 adequate trials of antidepressants. Participants were enrolled between March 1, 2019, and February 28, 2021; statistical analysis was performed from February 1 to June 15, 2022, using mixed models.

Intervention

Participants were randomized to receive standard care plus 20 mg/d of simvastatin or placebo.

Main Outcomes and Measures

The primary outcome was the difference between the 2 groups in change in Montgomery-Åsberg Depression Rating Scale total scores at week 12. Secondary outcomes included changes in scores on the 24-item Hamilton Rating Scale for Depression, the Clinical Global Impression scale, and the 7-item Generalized Anxiety Disorder scale and change in body mass index from baseline to week 12. C-reactive protein and plasma lipids were measured at baseline and week 12.

Results

A total of 150 participants were randomized to simvastatin (n = 77; median [IQR] age, 40 [30-45] years; 43 [56%] female) or placebo (n = 73; median [IQR] age, 35 [31-41] years; 40 [55%] female). A significant baseline to end point reduction in Montgomery-Åsberg Depression Rating Scale total score was observed in both groups and did not differ significantly between groups (estimated mean difference for simvastatin vs placebo, -0.61; 95% CI, -3.69 to 2.46; P = .70). Similarly, there were no significant group differences in any of the secondary outcomes or evidence for differences in adverse effects between groups. A planned secondary analysis indicated that changes in plasma C-reactive protein and lipids from baseline to end point did not mediate response to simvastatin.

Conclusions and Relevance

In this randomized clinical trial, simvastatin provided no additional therapeutic benefit for depressive symptoms in TRD compared with standard care.

Trial Registration

ClinicalTrials.gov Identifier: NCT03435744.

Neurobiological Mechanisms Of Depression Following Traumatic Brain Injury

OBJECTIVE

Depression is among the most pervasive and debilitating neuropsychiatric sequelae experienced by patients following a traumatic brain injury (TBI). While the individual mechanisms underlying depression and TBI have been widely studied, the neurobiological bases of depression after TBI remain largely unknown. This article highlights the potential mechanisms of action implicated in depression after TBI.

RESULTS

We review putative mechanisms of action including neuroinflammation, neuroendocrine dysregulation, metabolic abnormalities, and neurotransmitter and circuitry dysfunction. We also identify the current limitations in the field and propose directions for future research.

CONCLUSION

An improved understanding of the underlying mechanisms will aid the development of precision-guided and personalized treatments for patients suffering from depression after TBI.

Association between thyroid dysfunction, metabolic disturbances, and clinical symptoms in first-episode, untreated Chinese patients with major depressive disorder: Undirected and Bayesian network analyses

AIMS

Thyroid dysfunction and metabolic disturbances are common in major depressive disorder (MDD) patients. We aimed to assess the relationship between thyroid dysfunction, metabolic disturbances, and clinical symptoms in Chinese first-episode, drug-naïve (FEDN) MDD patients using undirected and Bayesian network methods.

METHODS

1718 FEDN MDD patients were recruited. Serum levels of free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), anti-thyroglobulin (TgAb), thyroid peroxidases antibody (TPOAb), total cholesterol (TC), total triglycerides (TG), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), and glucose were assessed. Blood pressure and body mass index were measured. Hamilton Rating Scale for Depression (HAMD), Hamilton Rating Scale for Anxiety, and positive subscale of Positive And Negative Syndrome Scales were used to detect clinical symptoms. An undirected network with EBICglasso default and a directed acyclic graph (DAG) using the Bayesian network approach was conducted.

RESULTS

The prevalence rates of clinical symptoms, thyroid dysfunction, and metabolic dysfunction were as follows: anxiety (n=894, 52%), psychotic symptoms (171, 10%), subclinical hypothyroidism (SCH, n=1041, 61%), abnormal TgAb (n=297, 17%), abnormal TPOAb (n=438, 25%), hyperthyroidism (n=5, 0.3%), hypothyroidism (n=3, 0.2%), hyperglycemia (n=241, 14%), hypertriglyceridemia (n=668, 39%), low HDL-C (n=429, 25%), hypercholesterolemia (421, 25%), abnormal TC (357, 21%), abnormal LDL-C (185, 11%). overweight or obesity (n=1026, 60%), and hypertension (n=92, 5.4%). Both networks demonstrated serum TSH and TC levels and the severity of depression played an important role in the pathophysiology of MDD.

CONCLUSIONS

MDD patients may have thyroid and metabolic dysfunction in the early stage. Targeting hypercholesterolemia, depressive symptoms, and SCH in MDD patients may hold promise in reducing clinical symptoms, metabolic disturbances, and thyroid dysfunction.

The Anti-Depressant Effects of Statins in Patients With Major Depression Post-Myocardial Infarction: An Updated Review 2022

Statins are the most commonly prescribed lipid-lowering agents in patients with cardiovascular disease, and more than half of the patients with cardiovascular disease have associated depressive symptoms, particularly post-myocardial infarction, which is a major trigger for depression. In our research, we tried to understand the anti-depressant effects of statins, the mechanisms, risks and benefits, and potential drug-drug interactions with anti-depressant medications. We reviewed all the relevant information from inception up to September 2022 regarding the anti-depressant effects of statins. The database used was PubMed, and the keywords were statins, major depression, post-myocardial infarction, and hydroxy methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors. We have screened each of the articles carefully, including both human and animal studies, and found a positive correlation between reduction in depressive symptoms with statin therapy as adjunctive treatment with conventional anti-depressants. In conclusion, statins as a monotherapy are not an effective treatment for depression post-myocardial infarction but are good add-on options along with standard therapy such as selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs). Statins are safe and have no serious drug-drug interactions with anti-depressants. We would like to encourage large-scale observational studies and further post-marketing surveillance to improve our knowledge regarding the effectiveness of statins in the treatment of depression.

Is depression the missing link between inflammatory mediators and cancer?

Patients with cancer are at greater risk of developing depression in comparison to the general population and this is associated with serious adverse effects, such as poorer quality of life, worse prognosis and higher mortality. Although the relationship between depression and cancer is now well established, a common underlying pathophysiological mechanism between the two conditions is yet to be elucidated. Existing theories of depression, based on monoamine neurotransmitter system dysfunction, are insufficient as explanations of the disorder. Recent advances have implicated neuroinflammatory mechanisms in the etiology of depression and it has been demonstrated that inflammation at a peripheral level may be mirrored centrally in astrocytes and microglia serving to promote chronic levels of inflammation in the brain. Three major routes to depression in cancer in which proinflammatory mediators are implicated, seem likely. Activation of the kynurenine pathway involving cytokines, increases tryptophan catabolism, resulting in diminished levels of serotonin which is widely acknowledged as being the hallmark of depression. It also results in neurotoxic effects on brain regions thought to be involved in the evolution of major depression. Proinflammatory mediators also play a crucial role in impairing regulatory glucocorticoid mediated feedback of the hypothalamic-pituitary-adrenal axis, which is activated by stress and considered to be involved in both depression and cancer. The third route is via the glutamatergic pathway, whereby glutamate excitotoxicity may lead to depression associated with cancer. A better understanding of the mechanisms underlying these dysregulated and other newly emerging pathways may provide a rationale for therapeutic targeting, serving to improve the care of cancer patients.

Statins in depression: a repurposed medical treatment can provide novel insights in mental health

Depression has a large burden, but the development of new drugs for its treatment has proved difficult. Progresses in neuroscience have highlighted several physiopathological pathways, notably inflammatory and metabolic ones, likely involved in the genesis of depressive symptoms. A novel strategy proposes to repurpose established medical treatments of known safety and to investigate their potential antidepressant activity. Among numerous candidates, growing evidence suggests that statins may have a positive role in the treatment of depressive disorders, although some have raised concerns about possible depressogenic effects of these widely prescribed medications. This narrative review summarises relevant findings from translational studies implicating many interconnected neurobiological and neuropsychological, cardiovascular, endocrine-metabolic, and immunological mechanisms by which statins could influence mood. Also, the most recent clinical investigations on the effects of statins in depression are presented. Overall, the use of statins for the treatment of depressive symptoms cannot be recommended based on the available literature, though this might change as several larger, methodologically robust studies are being conducted. Nevertheless, statins can already be acknowledged as a driver of innovation in mental health, as they provide a novel perspective to the physical health of people with depression and for the development of more precise antidepressant treatments.

Current Perspectives on Pharmacological and Non-Pharmacological Interventions for the Inflammatory Mechanism of Unipolar Depression

Since depression remains a major public health issue there is a constant need for new and more efficient therapeutic strategies based on the mechanisms involved in the aetiology of depression. Thus, the pathogenic link between depression and inflammation is considered to play a potential key role in the development of such therapies. This review summarizes the results of various pharmacological (non-steroidal anti-inflammatory drugs, aspirin, cyclooxygenase inhibitors, cytokine inhibitors, corticosteroids, statins, minocycline, N-acetyl cysteine, omega-3 fatty acids and probiotics) and non-pharmacological interventions (electroconvulsive therapy, physical exercise and psychological therapy) and outlines their efficacy and discusses potential challenges. Both conventional and non-conventional anti-inflammatory drugs showed promising results according to the specific group of patients. The pre-existing pro-inflammatory status was, in most cases, a predictor for clinical efficacy and, in some cases, a correlation between clinical improvement and changes in various biomarkers was found. Some of the non-pharmacological interventions (physical exercise and electroconvulsive therapy) have also showed beneficial effects for depressive patients with elevated inflammatory markers. Treatments with anti-inflammatory action may improve clinical outcomes in depression, at least for some categories of patients, thus opening the way for a future personalised approach to patients with unipolar depression regarding the inflammation-related mechanism.

Associations Between Statin Use and Negative Affective Bias During COVID-19: An Observational, Longitudinal UK Study Investigating Depression Vulnerability

BACKGROUND

There is growing interest in the antidepressant potential of statins. We tested whether statin use is associated with cognitive markers previously found to indicate psychological vulnerability to depression within the context of the COVID-19 pandemic.

METHODS

Between April 2020 and February 2021, we conducted an observational online study of 2043 adults in the United Kingdom. Participants completed cognitive tasks assessing processes related to depression vulnerability, including affective bias and reward processing. We also measured working memory, medication use, and current psychiatric symptoms. Using mixed analysis of covariance and regression models, we compared participants on statins alone (n = 81), antihypertensive medication alone (n = 126), both medications (n = 111), and on neither medication (n = 1725).

RESULTS

Statin use was associated with reduced recognition of angry and fearful faces (F₁ = 9.19, p = .002; F₁ = 6.9, p = .009) and with increased misclassification of these expressions as positive. Increased recognition of angry faces at baseline predicted increased levels of depression and anxiety 10 months later (β = 3.61, p = .027; β = 2.37, p = .002). Statin use was also associated with reduced learning about stimuli associated with loss (F_1,1418 = 9.90, p = .002). These indicators of reduced negative bias were not seen in participants taking antihypertensive medication alone, suggesting that they were related to statin use in particular rather than nonspecific demographic factors. In addition, we found no evidence of an association between statin use and impairment in working memory.

CONCLUSIONS

Statin use was associated with cognitive markers indicative of reduced psychological vulnerability to depression, supporting their potential use as a prophylactic treatment for depression.

The effects of statin monotherapy on depressive symptoms: A systematic review and meta-analysis

INTRODUCTION

Statins have been proposed as a strategy for treating depression, but their benefit in the absence of concurrent antidepressant treatment is unclear. This meta-analysis investigated the antidepressant effects of statin monotherapy in the general population.

METHODS

We conducted a literature search of randomised controlled trials using any statin monotherapy versus any control condition for depressive symptoms. Our primary efficacy outcome was the mean value on any standardised scale for depression at study endpoint. We also measured efficacy at three further timepoints (<6 months, 6-12 months, >12 months), as well as acceptability, tolerability, and safety. Respectively, continuous and dichotomous outcomes were computed using standardised mean difference (SMD) or relative risk (RR) with 95% confidence intervals (CI) using a random-effect model.

RESULTS

Pooled analyses did not show that statin monotherapy improves depressive symptoms at endpoint (N = 2712 SMD = -0.18; 95% CI = -0.41 to 0.04), nor at any other specific timepoint. No difference between statins and control was identified for any of the other outcome measures.

DISCUSSION

These results differ from those of previous meta-analyses and, compounded by more recently available evidence, suggest that statins may not have intrinsic antidepressant properties, but may be useful for the management of depression in add-on to antidepressants.

LIMITATIONS

Data from heterogeneous populations and using different statins were pooled, though several sensitivity and subgroup analyses were performed to account for that. PROSPERO registration: CRD42022306653. https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=306653.

An experimental medicine study of the effects of simvastatin on emotional processing, reward learning, verbal memory, and inflammation in healthy volunteers

RATIONALE

Clinical studies suggest that the highly lipophilic, anti-inflammatory molecule, simvastatin, might be an ideal candidate for drug repurposing in the treatment of depression. The neuropsychological effects of simvastatin are not known, but their ascertainment would have significant translational value about simvastatin's influence on mood and cognition.

OBJECTIVES

We aimed to investigate the effects of simvastatin on a battery of psychological tests and inflammatory markers in healthy volunteers.

METHODS

Fifty-three healthy subjects were randomly assigned to 7 days of either simvastatin (N = 27) or sucrose-based placebo (N = 26) given in a double-blind fashion. Then, participants were administered questionnaires measuring subjective rates of mood and anxiety, and a battery of tasks assessing emotional processing, reward learning, and verbal memory. Blood samples for C-reactive protein were also collected.

RESULTS

Compared to placebo, participants on simvastatin showed a higher number of positively valenced intrusions in the emotional recall task (F1,51 = 4.99, p = 0.03), but also an increase in anxiety scores (F1,51 = 5.37, p = 0.02). An exploratory analysis of the females' subgroup (N = 27) showed lower number of misclassifications as sad facial expression in the simvastatin arm (F1,25 = 6.60, p = 0.02). No further statistically significant changes could be observed on any of the other outcomes measured.

CONCLUSIONS

We found limited evidence that 7-day simvastatin use in healthy volunteer induces a positive emotional bias while also being associated with an increase in anxiety, potentially reflecting the early effects of antidepressants in clinical practice. Such effect might be more evident in female subjects. Different drug dosages, treatment lengths, and sample selection need consideration in further experimental medicine and clinical studies.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04652089.

Association of the Dietary Inflammatory Index with Depressive Symptoms among Pre- and Post-Menopausal Women: Findings from the National Health and Nutrition Examination Survey (NHANES) 2005-2010

During their lifetime, 20% of US women experience depression. Studies have indicated that a high Dietary Inflammatory Index (DII) score is associated with high C-reactive protein (CRP) levels and depression. No previous study has compared the association of the DII with different measures of depression (e.g., somatic, cognitive) among pre- and post-menopausal women. We used data from 2512 pre-menopausal and 2392 post-menopausal women from the National Health and Nutrition Examination Survey (NHANES) 2005−2010 database. We ran linear and logistic regression models to compare the association of the DII with survey-measured depression among pre- and post-menopausal women. We further assessed the mediation effect of CRP on the association of the DII and depression, using structural equation modeling. The odds of experiencing depression among pre-menopausal women was higher for all DII quartiles compared to the reference group (i.e., DII Q1), with an odds ratio (OR) of 3.2, 5.0, and 6.3 for Q2, Q3, and Q4, respectively (p < 0.05). Among post-menopausal women, only Q4 had 110% higher odds of experiencing depression compared to Q1 (p = 0.027). No mediation effect of CRP was found between DII and any of our depression outcome measures. Our findings suggest that lifestyle habits, such as diet, may have a stronger influence on mental health among pre-menopausal women than post-menopausal women.

The effects of atorvastatin on emotional processing, reward learning, verbal memory and inflammation in healthy volunteers: An experimental medicine study

BACKGROUND

Growing evidence from clinical trials and epidemiological studies suggests that statins can have clinically significant antidepressant effects, potentially related to anti-inflammatory action on several neurobiological structures. However, the underlying neuropsychological mechanisms of these effects remain unexplored.

AIMS

In this experimental medicine trial, we investigated the 7-day effects of the lipophilic statin, atorvastatin on a battery of neuropsychological tests and inflammation in healthy volunteers.

METHODS

Fifty healthy volunteers were randomised to either 7 days of atorvastatin 20 mg or placebo in a double-blind design. Participants were assessed with psychological questionnaires and a battery of well-validated behavioural tasks assessing emotional processing, which is sensitive to putative antidepressant effects, reward learning and verbal memory, as well as the inflammatory marker, C-reactive protein.

RESULTS

Compared to placebo, 7-day atorvastatin increased the recognition (p = 0.006), discriminability (p = 0.03) and misclassifications (p = 0.04) of fearful facial expression, independently from subjective states of mood and anxiety, and C-reactive protein levels. Otherwise, atorvastatin did not significantly affect any other psychological and behavioural measure, nor peripheral C-reactive protein.

CONCLUSIONS

Our results reveal for the first time the early influence of atorvastatin on emotional cognition by increasing the processing of anxiety-related stimuli (i.e. increased recognition, discriminability and misclassifications of fearful facial expression) in healthy volunteers, in the absence of more general effects on negative affective bias. Further studies exploring the effects of statins in depressed patients, especially with raised inflammatory markers, may clarify this finding and inform future clinical trials.