Vitamin D: a potential role in reducing suicide risk?

Vitamin D in Depression: A Potential Bioactive Agent to Reduce Suicide and Suicide Attempt Risk

Suicide is one of the leading causes of death worldwide. According to the World Health Organization (WHO), every year, more than 700 thousand people die from this cause. Therefore, suicide is a public health issue. The complex interaction between different factors causes suicide; however, depression is one of the most frequent factors in people who have attempted suicide. Several studies have reported that vitamin D deficiency may be a relevant risk factor for depression, and vitamin D supplementation has shown promising effects in the adjunctive treatment of this mood disorder. Among the beneficial mechanisms of vitamin D, it has been proposed that it may enhance serotonin synthesis and modulate proinflammatory cytokines since low serotonin levels and systemic inflammation have been associated with depression and suicide. The present narrative review shows the potential pathogenic role of vitamin D deficiency in depression and suicide and the potential benefits of vitamin D supplementation to reduce their risk.

Suicide and Suicidality in Children and Adolescents with Chronic Skin Disorders: A Systematic Review

Suicide in young children is rare; the incidence increases towards the end of adolescence. Skin disorders confer a high prevalence of psychiatric and psycho-logical comorbidities. However, published research on suicidal behaviour in adolescents and children with skin disorders is sparse. The aim of this study was to identify the prevalence of suicidal behaviour in children and adolescents under 18 years of age with chronic skin disorders and associated contributing risk factors. MEDLINE, PsycINFO, EMBASE, CINAHL and Cochrane databases were searched from inception to October 2020 for suicide or suicide attempts in patients under 18 years old with chronic skin disorders. The study protocol was logged on PROSPERO (CRD42020083528). Returned texts were reviewed independently by 2 authors. Bias was assessed according to Joanna Briggs Institute criteria. Five studies met the inclusion criteria; 4 cross-sectional surveys and 1 retrospective matched-cohort study. A total of 31,641 patients with acne, atopic dermatitis, body dysmorphic disorder or psoriasis were identified. Prevalence of suicidal ideation was 0.45% (psoriasis) to 67% (body dysmorphic disorder). The prevalence of suicidal attempts ranged from 0.08% (psoriasis) to 21.9% (acne). Patients with acne or atopic dermatitis had significantly increased odds ratio for suicidal attempts. Meta-analysis could not be performed owing to the heterogeneity and sparsity of data. Suicidal risk in skin disorders amongst adolescents and children under the age of 18 years old is broad and complex. The suicidal risk remained after adjusting for depression, suggestive of an alternative mechanism.

25(OH)D levels are decreased in patients with difficult-to-treat depression

Objectives

The aims of the study are i) to compare 25-hydroxyvitamin D (25(OH)D) levels between clinically depressed individuals with insufficient treatment response and healthy controls and ii) to test the association between 25(OH)D levels and different affective disorder diagnoses (i.e., major depressive disorder (MDD) single episode, MDD recurrent episode, chronic MDD, and dysthymia), as well as grade of suicidal ideation.

Method

We quantified serum 25(OH)D in 202 individuals with difficult-to-treat depression (DTD) and 41 healthy controls. Patients were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, 4^th Edition (DSM-IV-TR). ANCOVA was used to test differences in mean 25(OH)levels between depressed and controls, adjusting for sex, age, smoking, sampling season, ethnicity, somatic illness, and body mass index (BMI). Binary logistic regression models were used to test the association between depression and 25(OH)D levels.

Results

Patients with difficult-to-treat depression had significantly lower levels of 25(OH)D compared to healthy controls (ANCOVA, F = 4.89; p = 0.03). Thirty percent of the depressed patients were 25(OH)D deficient (<50 nmol/L) compared to 5% of the controls (Chi-squared test, χ² = 11.38; p < 0.01). The odds for being depressed decreased significantly with 17% per 10 nmol/L increase of 25(OH)D (Binary logistic regression, p < 0.05).

Limitations

The cross-sectional design of the study precludes any conclusions about causality. A large part of the patients took psychotropic drugs and/or had somatic illnesses, which might have affected the results.

Conclusion

The results of the present study add to the body of evidence linking 25(OH)D deficiency and depression. Further investigations are warranted to better understand any clinical implications of this association.

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Lower 25(OH)D levels in difficult-to-treat depression versus healthy controls.

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No difference in 25(OH)D levels between different affective disorder diagnoses.

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No associations between 25(OH)D and suicidality.

Effects of vitamin D-related gene polymorphisms on attempted suicide

OBJECTIVE

Emerging evidence suggests that vitamin D might protect from attempted suicide. The study aimed to investigate the associations between single-nucleotide polymorphisms (SNPs) related to vitamin D levels identified in a large genome-wide association study and attempted suicide in rural China.

METHODS

This 1:1 matched case-control study included altogether 510 suicide attempters and 510 community controls. Genotypes of four target SNPs (DHCR7-rs12785878, CYP2R1-rs10741657, GC-rs2282679, and CYP24A1-rs6013897) were determined, and a genetic risk score (GRS) was constructed to evaluate the combined effect of them. Demographic and psychological information was acquired through face-to-face interviews.

RESULTS

The A allele of CYP24A1-rs6013897 was significantly associated with attempted suicide (OR = 1.27, 95% CI, 1.03-1.58, P = 0.029), even after adjusting for demographic and psychological confounders (adjusted OR = 1.53, 95% CI, 1.01-2.30, P = 0.043). The GRS analyses revealed a significantly higher risk of attempted suicide with a greater number of low vitamin D alleles (adjusted OR = 1.33, 95% CI, 1.13-1.58, P < 0.001). Subgroup analyses stratified by sex indicated that the genetic associations were only significant among males with adjusted ORs of 3.77 (95% CI, 1.56-9.10) for the A allele of rs6013897 and 2.04 (95% CI, 1.32-3.17) for GRS.

CONCLUSIONS

Our findings identity CYP24A1-rs6013897 as a potential biomarker for attempted suicide and indicate that a genetic predisposition to lower vitamin D levels may contribute to attempted suicide. It suggests the possibility that vitamin D may have the preventive potential for attempted suicide.

Vitamin D and N-Acetyl Cysteine Supplementation in Treatment-Resistant Depressive Disorder Patients: A General Review

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Major Depressive Disorder (MDD) is often a lifetime disabling mental illness as individuals with MDD might not benefit from standard-therapy, including both pharmacological and psychosocial interventions. Novel therapies are, therefore, required.

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It was shown by recent preclinical and clinical studies that the dysfunction of glutamatergic neurotransmission might be involved in the pathophysiology of MDD. Furthermore, neuroimmune alterations could have a significant role in the pathogenesis of MDD.

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Vitamin D is a neurosteroid hormone essential for several metabolic processes, immune responses, and for regulating neurotrophic-neuroprotective processes, neurotransmission and synaptic plasticity. Recent studies have also shown Vitamin D deficiency in patients with severe psychiatric disorders, including MDD.

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Lately, clinical studies have shown the neuroprotective action of N-acetyl cysteine (NAC) through the modulation of inflammatory pathways and via the modulation of synaptic release of glutamate in cortico-subcortical brain regions; the cysteine-glutamate antiporter.

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This paper reviews the therapeutic use of Vitamin D and NAC and among individuals with refractory MDD to the first- line pharmacological interventions, reviewing the clinical studies published in the last decade.

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A detailed summary of the current evidence in this area aims to better inform psychiatrists and general practitioners on the potential benefits of Vitamin D and NAC supplementation for this disorder.

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Nutraceutical supplementation with Vitamin D and NAC in treatment-resistant MDD patients may be important not only for improving depressive clinical manifestations but also for their safety and tolerability profile. This is of great interest, especially considering the need for treating special populations affected by MDD, such as youngsters and elders. Finally, the nutraceutical approach represents a good choice, considering its better compliance by the patients compared to traditional psychopharmacological treatment.

Increased brain vitamin D receptor expression and decreased expression of cathelicidin antimicrobial peptide in individuals who died by suicide

Vitamin D deficiency is associated with immune dysregulation, increased vulnerability to infections, depression, and suicidal behavior. One mediator of vitamin D-dependent immune regulation and antimicrobial defense is the cathelicidin antimicrobial peptide (LL-37), encoded by the cathelicidin-related antimicrobial peptide (CRAMP) gene. We compared the mRNA expression of the CRAMP gene, the vitamin D receptor (VDR) gene, as well as the CYP27B1 and CYP24A1 genes (involved in vitamin D metabolism) in the dorsolateral prefrontal cortex (dlPFC) and anterior cingulate cortex (ACC) between depressed individuals who died by suicide (n = 15) and matched (age, gender, and post-mortem interval) non-psychiatric controls (n = 15). Gene expression was measured through qRT-PCR with TaqMan® primers and probes, with GAPDH and β-actin genes as endogenous controls. Statistical analyses included t-tests and Pearson correlations. CRAMP mRNA expression was downregulated and VDR mRNA expression was upregulated in both dlPFC and ACC in suicides relative to controls, with no significant differences in expression of CYP24A1 and CYP27B1. To our knowledge, this is the first study on brain cathelicidin expression in the human brain in relationship to suicide. Increased VDR and decreased CRAMP expression are consistent with previously reported associations between vitamin D deficiency, immune dysregulation, and suicidal behavior, and should lead to future studies uncovering novel interactive targets for suicide prevention.

Vitamin D and inflammation in major depressive disorder

BACKGROUND

Increased inflammation is reported in Major Depressive Disorder (MDD), which may be more pronounced in suicidal subjects. Vitamin D deficiency may drive this pro-inflammatory state due to vitamin D's anti-inflammatory effects.

METHODS

We quantified plasma 25-hydroxyvitamin D (25(OH)D) and inflammatory markers interleukin (IL)-6 and tumor necrosis factor (TNF)-α, and other inflammatory indices, neutrophil-to-lymphocyte ratio (NLR) and white blood cell count (WBC) in 48 un-medicated MDD subjects (n = 17 with mild-to-moderate suicidal ideation [SI]) and 54 controls. IL-6 and TNF-α were combined into a composite inflammation score.

RESULTS

There were no significant differences in 25(OH)D levels between MDD and controls (p = 0.24) or between MDD with and without SI (p = 0.61). However, 25(OH)D was negatively correlated with all measured inflammatory markers; these correlations were stronger in MDD subjects, and particularly in those with SI. MDD status significantly moderated the relationships between 25(OH)D and NLR (p = 0.03), and 25(OH)D and WBC (p < 0.05), and SI significantly moderated the relationship between 25(OH)D and NLR (p = 0.03).

LIMITATIONS

The study was cross-sectional, thereby limiting causal inference, and had a small sample size. Only seventeen of the MDD subjects had SI.

CONCLUSION

While 25(OH)D levels did not significantly differ in MDD vs. controls, or in MDD with or without SI, lower 25(OH)D was associated with indices of immune activation in MDD, especially in cases with SI. Although our findings do not address causality, they are consistent with findings that relatively low 25(OH)D levels in MDD are associated with a pro-inflammatory state.

Serum 25-hydroxyvitamin D and mental health in young Australian women: Results from the Safe-D study

BACKGROUND

While there is evidence linking vitamin D status with mood, this association and its clinical significance remain uncertain. Moreover, few studies have focused on young, community-dwelling females. The Safe-D study examined the association between serum 25-hydroxyvitamin D (25OHD) levels and mental health in young women.

METHODS

Participants completed an online questionnaire, wore a UV dosimeter to measure personal sun exposure and underwent a comprehensive health assessment. Serum 25OHD was measured by liquid chromatography-tandem mass spectrometry in 353 healthy women aged 16-25 years, living in Victoria, Australia. Mental health measures included: Patient Health Questionnaire (PHQ-9), 7-item Generalized Anxiety Disorder Scale (GAD-7), Kessler psychological distress scale (K10) and 12-item short-form health survey (SF-12), plus any self-reported mental disorder diagnoses or medication use.

RESULTS

The prevalence of self-reported mental disorder was 26% and of vitamin D deficiency 27%. The median (Q1, Q3) scores for the PHQ-9, GAD-7, K10 and SF-12 MCS were 6 (3, 9), 5 (2, 8), 19 (15, 25) and 43 (34, 49), respectively. Serum 25OHD levels were not associated with mental health scores. Vitamin D status was not associated with a reported diagnosis of depression or anxiety.

LIMITATIONS

There was a low prevalence of severe vitamin D deficiency and mental health symptoms, which may reduce study power.

CONCLUSION

Our findings do not support an association between serum 25OHD levels and mental health status in young women. Longitudinal studies and randomized clinical trials investigating vitamin D and mood in young women are needed to confirm and extend these results.

Vitamin D supplementation in bipolar depression: A double blind placebo controlled trial

OBJECTIVE

Bipolar depression is difficult to treat. Vitamin D supplementation is well tolerated and may improve mood via its neurotransmitter synthesis regulation, nerve growth factor enhancement and antioxidant properties. Vitamin D adjunct reduces unipolar depression, but has not been tried in bipolar depression.

METHODS

18-70yos with DSM IV bipolar depression and Vitamin D deficiency (<30 ng/ml) were randomized in a controlled double blind trial of 5000IU Vitamin D₃ po qday supplementation versus placebo for twelve weeks. Change in Montgomery-Åsberg Depression Rating Scale (MADRS), Hamilton Anxiety Rating Scale (HAM-A), Young Mania Rating Scale (YMRS), medication, and tolerance were assessed q2weeks.

RESULTS

16 VitD vs 17 placebo subjects did not differ in baseline characteristics (mean = 44 yo, SD = 13), VitD level (19.2 ± 65.8  g/ml vs 19.3 ± 5.5 ng/ml respectively) or mood ratings (MADRS 21.3 ± 6.4 vs 22.8 ± 6.9 respectively). At 12wks, the placebo group VitD levels remained unchanged, while the VitD group levels increased to 28 ng/ml. MADRS score decreased significantly in both placebo (mean = 6.42 (95% CI [2.28 to 10.56]) and VitD groups (mean = 9.54 (95% CI[3.51 to 15.56]) (p = 0.031), but there were no differences between treatment groups (time by treatment interaction estimate: 0.29, t₍₂₃₎ = 0.14, p = 0.89); VitD and placebo groups had similar reductions in YMRS and HAM-A. Vitamin D₃ was well tolerated.

CONCLUSIONS

In this small study, despite a greater rise in Vitamin D levels in the VitD supplementation group, there was no significant difference reduction in depressive symptoms. However both groups' VitD levels remained deficient. Vitamin D₃ supplementation vs placebo did not improve reduction in mood elevation or anxiety symptoms.

Impact of Enriched Environment on Murine T Cell Differentiation and Gene Expression Profile

T cells are known to be plastic and to change their phenotype according to the cellular and biochemical milieu they are embedded in. In this study, we transposed this concept at a macroscopic level assessing whether changes in the environmental housing conditions of C57/BL6 mice would influence the phenotype and function of T cells. Our study shows that exposure to 2 weeks in an enriched environment (EE) does not impact the T cell repertoire in vivo and causes no changes in the early TCR-driven activation events of these cells. Surprisingly, however, T cells from enriched mice showed a unique T helper effector cell phenotype upon differentiation in vitro. This was featured by a significant reduction in their ability to produce IFN-γ and by an increased release of IL-10 and IL-17. Microarray analysis of these cells also revealed a unique gene fingerprint with key signaling pathways involved in autoimmunity being modulated. Together, our results provide first evidence for a specific effect of EE on T cell differentiation and its associated changes in gene expression profile. In addition, our study sheds new light on the possible mechanisms by which changes in environmental factors can significantly influence the immune response of the host and favor the resolution of the inflammatory response.

Suicidal patients are deficient in vitamin D, associated with a pro-inflammatory status in the blood

BACKGROUND

Low levels of vitamin D may play a role in psychiatric disorders, as cross-sectional studies show an association between vitamin D deficiency and depression, schizophrenia and psychotic symptoms. The underlying mechanisms are not well understood, although vitamin D is known to influence the immune system to promote a T helper (Th)-2 phenotype. At the same time, increased inflammation might be of importance in the pathophysiology of depression and suicide. We therefore hypothesized that suicidal patients would be deficient in vitamin D, which could be responsible for the inflammatory changes observed in these patients.

METHODS

We compared vitamin D levels in suicide attempters (n=59), non-suicidal depressed patients (n=17) and healthy controls (n=14). Subjects were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, and went through a structured interview by a specialist in psychiatry. 25(OH)D2 and 25(OH)D3 were measured in plasma using liquid-chromatography-mass-spectrometry (LC-MS). We further explored vitamin D's association with plasma IL-1β, IL-6 and TNF-α.

RESULTS

Suicide attempters had significantly lower mean levels of vitamin D than depressed non-suicidal patients and healthy controls. 58 percent of the suicide attempters were vitamin D deficient according to clinical standard. Moreover, there was a significant negative association between vitamin D and pro-inflammatory cytokines in the psychiatric patients. Low vitamin D levels were associated with higher levels of the inflammatory cytokines IL-6 and IL-1β in the blood.

CONCLUSION

The suicide attempters in our study were deficient in vitamin D. Our data also suggest that vitamin D deficiency could be a contributing factor to the elevated pro-inflammatory cytokines previously reported in suicidal patients. We propose that routine clinical testing of vitamin D levels could be beneficial in patients with suicidal symptoms, with subsequent supplementation in patients found to be deficient.

Low-intensity treadmill exercise and/or bright light promote neurogenesis in adult rat brain

The hippocampus is a brain region responsible for learning and memory functions. The purpose of this study was to investigate the effects of low-intensity exercise and bright light exposure on neurogenesis and brain-derived neurotrophic factor expression in adult rat hippocampus. Male Sprague-Dawley rats were randomly assigned to control, exercise, light, or exercise + light groups (n = 9 per group). The rats in the exercise group were subjected to treadmill exercise (5 days per week, 30 minutes per day, over a 4-week period), the light group rats were irradiated (5 days per week, 30 minutes per day, 10 000 lx, over a 4-week period), the exercise + light group rats were subjected to treadmill exercise in combination with bright light exposure, and the control group rats remained sedentary over a 4-week period. Compared with the control group, there was a significant increase in neurogenesis in the hippocampal dentate gyrus of rats in the exercise, light, and exercise + light groups. Moreover, the expression level of brain-derived neurotrophic factor in the rat hippocampal dentate gyrus was significantly higher in the exercise group and light group than that in the control group. Interestingly, there was no significant difference in brain-derived neurotrophic factor expression between the control group and exercise + light group. These results indicate that low-intensity treadmill exercise (first 5 minutes at a speed of 2 m/min, second 5 minutes at a speed of 5 m/min, and the last 20 minutes at a speed of 8 m/min) or bright-light exposure therapy induces positive biochemical changes in the brain. In view of these findings, we propose that moderate exercise or exposure to sunlight during childhood can be beneficial for neural development.

Natural products and supplements for geriatric depression and cognitive disorders: an evaluation of the research

Numerous geriatric patients are using Complementary and Alternative Medicine (CAM) for late-life mood and cognitive disorders. Natural products and supplements are a common CAM intervention which have risks and benefits of which patients should be appropriately advised. The data for omega-3 fatty acids, ginkgo biloba, SAMe, St John's wort, B vitamins and vitamin D, huperzine, caprylidene, and coconut oil will be evaluated. Since the evidence basis for natural products and supplements is limited, especially for the geriatric population, studies involving the general adult population are included to infer effects in the aging population. Despite the data available, more rigorous studies with larger sample sizes over longer periods of time are still needed. Regardless of a physician's preference to recommend various natural supplements and products, a physician could protect their patients by having an understanding of the side effects and indications for various natural products.

Single-micronutrient and broad-spectrum micronutrient approaches for treating mood disorders in youth and adults

Several different vitamins and minerals appear to be effective augmenting agents for mood-modifying drugs, but are not potent monotherapies in themselves for treating psychiatric disorders. In contrast, broad-spectrum micronutrient interventions appear in early trials to be as effective as psychiatric medications with fewer adverse effects for treating mood disorders, ADHD, aggressivity, and misconduct in youth and adults. Broad-spectrum treatments also may improve stress responses, cognition, and sense of well-being in healthy adults, but have been less well studied in youth. Current clinical data justify an extensive expansion of research on micronutrient mechanisms and treatments in psychiatry.

Mood disorders and complementary and alternative medicine: a literature review

Mood disorders are a major public health problem and are associated with considerable burden of disease, suicides, physical comorbidities, high economic costs, and poor quality of life. Approximately 30%-40% of patients with major depression have only a partial response to available pharmacological and psychotherapeutic interventions. Complementary and alternative medicine (CAM) has been used either alone or in combination with conventional therapies in patients with mood disorders. This review of the literature examines evidence-based data on the use of CAM in mood disorders. A search of the PubMed, Medline, Google Scholar, and Quertile databases using keywords was conducted, and relevant articles published in the English language in the peer-reviewed journals over the past two decades were retrieved. Evidence-based data suggest that light therapy, St John's wort, Rhodiola rosea, omega-3 fatty acids, yoga, acupuncture, mindfulness therapies, exercise, sleep deprivation, and S-adenosylmethionine are effective in the treatment of mood disorders. Clinical trials of vitamin B complex, vitamin D, and methylfolate found that, while these were useful in physical illness, results were equivocal in patients with mood disorders. Studies support the adjunctive role of omega-3 fatty acids, eicosapentaenoic acid, and docosahexaenoic acid in unipolar and bipolar depression, although manic symptoms are not affected and higher doses are required in patients with resistant bipolar depression and rapid cycling. Omega-3 fatty acids are useful in pregnant women with major depression, and have no adverse effects on the fetus. Choline, inositol, 5-hydroxy-L-tryptophan, and N-acetylcysteine are effective adjuncts in bipolar patients. Dehydroepiandrosterone is effective both in bipolar depression and depression in the setting of comorbid physical disease, although doses should be titrated to avoid adverse effects. Ayurvedic and homeopathic therapies have the potential to improve symptoms of depression, although larger controlled trials are needed. Mind-body-spirit and integrative medicine approaches can be used effectively in mild to moderate depression and in treatment-resistant depression. Currently, although CAM therapies are not the primary treatment of mood disorders, level 1 evidence could emerge in the future showing that such treatments are effective.