Effect of vitamin D deficiency on depressive symptoms in child and adolescent psychiatric patients: results of a randomized controlled trial

Cognitive Functions in Adolescent Girls with Anorexia Nervosa during Nutritional Rehabilitation

BACKGROUND

The present study aimed to evaluate cognitive function and laboratory parameters in adolescent girls with anorexia nervosa (AN) before and after nutritional rehabilitation (NR) compared to healthy female peers (CG).

METHODS

We evaluated 36 girls with AN at two-time points, during acute malnutrition (AN1) and after NR, in a partially normalized weight status (AN2). We compared their cognitive functions and laboratory parameters to 48 healthy CG subjects. Cognitive function was assessed using a Cognitive Assessment Battery (CAB) assessment, depressive symptom levels were assessed using a Beck Depression Inventory (BDI) assessment, and eating disorders were assessed using an Eating Attitude Test (EAT-26).

RESULTS

The AN1 group scored better in total cognition, attention, estimation, and spatial perception than the CG group (p < 0.05), with scores increasing in the AN2 group. Shifting and visual perception values did not differ between the study groups (p = 0.677, p = 0.506, respectively). Laboratory tests showed no significant abnormalities and did not differ significantly between groups (p > 0.05). There was a negative correlation for EAT-26 and CAB in the AN1 group (rho = -0.43, p = 0.01), but not for BDI.

CONCLUSIONS

Cognitive function in adolescent girls with AN was better than CG and correlated with EAT-26 score. These results highlight the high compensatory capacity of the adolescent body to maintain cognitive function despite severe malnutrition. Our results suggest that although normalization of body weight is crucial, other factors can significantly influence improvements in cognitive function. Cognitive deficits and laboratory tests may not be biomarkers of early forms of AN.

Association of cord blood vitamin D with child neurodevelopment at 7 years of age

AIM

The role of fetal vitamin D [25-hydroxyvitamin D (25(OH)D)], one of the nuclear steroid transcription regulators, and brain development is unclear. We previously found a weak but persistent association between cord blood 25(OH)D and child language abilities at 18 months and 4 years of age, but no association with cognition or behaviour. The aim of this study was to investigate the association between cord blood 25(OH)D and a range of neurodevelopmental outcomes in these same children at 7 years of age.

METHODS

Cord blood samples from 250 Australian mother-child pairs were analysed for 25(OH)D by mass spectroscopy. Children underwent tests of cognition, language, academic abilities and executive functions with a trained assessor at 7 years of age. Caregivers completed questionnaires to rate their child's behaviour and executive functioning in the home environment. Associations between standardised 25(OH)D and outcomes were assessed using regression models, taking into account possible social and demographic confounders.

RESULTS

Standardised 25(OH)D in cord blood was not associated with any test or parent-rated scores. Nor was there any association with the risk of having a poor test or parent-rated score. Likewise, cord blood 25(OH)D categorised as <25, 25-50 and >50 nmol/L was not associated with test scores or parent-rated scores.

CONCLUSIONS

There was no evidence that cord blood vitamin D concentration or deficiency was associated with cognition, language, academic abilities, executive functioning or behaviour at 7 years of age.

Does Vitamin D3 Supplementation Improve Depression Scores among Rural Adolescents? A Randomized Controlled Trial

BACKGROUND

Contemporary evidence has been established demonstrating that stunted vitamin D levels are associated with depression, poor mood, and other mental disorders. Individuals with normal vitamin D levels have a much lower probability of developing depression. Improving vitamin D levels by supplementation has shown betterment in depressive patients among different age groups. The objective of this study was to assess the effect of vitamin D supplementation on depression scores among rural adolescents.

MATERIAL AND METHODS

This study was a cluster randomized controlled trial carried out for a period of 3 years among adolescents from rural Kolar. The sample size was calculated based on previous research and was determined to be 150 for each group. The intervention arm received 2250 IU of vitamin D, and the control arm received a lower dose of 250 IU of vitamin D for 9 weeks. To assess sociodemographic status, a pretested, semi-structured questionnaire was used, and, to assess depression, the Beck Depression Inventory (BDI-II) was used. A baseline assessment was carried out for vitamin D status and depression status, followed by a post-intervention assessment. From the start of the trial, the participants were contacted every week by the pediatric team to investigate any side effects.

RESULTS

Out of 235 school students in the vitamin D supplementation arm, 129 (54.9%) belonged to the 15 years age group, 124 (52.8%) were boys, and 187 (79.6%) belonged to a nuclear family. Out of 216 school students in the calcium supplementation arm, 143 (66.2%) belonged to the 15 years age group, 116 (53.7%) were girls, and 136 (63%) belonged to a nuclear family. By comparing Beck depression scores before and after the intervention, it was found that the vitamin D intervention arm showed a statistically significant reduction in Beck depression scores.

CONCLUSIONS

The present study showed that vitamin D supplementation reduced depression scores, showing some evidence that nutritional interventions for mental health issues such as depression are an excellent option. Vitamin D supplementation in schools can have numerous beneficiary effects on health while mutually benefiting mental health.

Nutraceuticals in Psychiatric Disorders: A Systematic Review

Correct nutrition and diet are directly correlated with mental health, functions of the immune system, and gut microbiota composition. Diets with a high content of some nutrients, such as fibers, phytochemicals, and short-chain fatty acids (omega-3 fatty acids), seem to have an anti-inflammatory and protective action on the nervous system. Among nutraceuticals, supplementation of probiotics and omega-3 fatty acids plays a role in improving symptoms of several mental disorders. In this review, we collect data on the efficacy of nutraceuticals in patients with schizophrenia, autism spectrum disorders, major depression, bipolar disorder, and personality disorders. This narrative review aims to provide an overview of recent evidence obtained on this topic, pointing out the direction for future research.

Celiac disease and depressive disorders as nutritional implications related to common factors - A comprehensive review

Celiac disease (CD) is an immune-mediated disease affecting the small intestine. The only treatment strategy for CD is the gluten-free diet (GFD). One of the more common mental disorders in CD patients is major depressive disorder (MDD). The influence of GFD on the occurrence of MDD symptoms in patients with CD will be evaluated. This diet often reduces nutritional deficiencies in these patients and also helps to reduce depressive symptoms. Both disease entities are often dominated by the same deficiencies of nutrients such as iron, zinc, selenium, iodine, or B and D vitamins. Deficiencies of particular components in CD can favor MDD and vice versa. Gluten can adversely affect the mental state of patients without CD. Also, intestinal microbiota may play an important role in the described process. This work aims to comprehensively assess the common factors involved in the pathomechanisms of MDD and CD, with particular emphasis on nutrient imbalances. Given the complexity of both disease entities, and the many common links, more research related to improving mental health in these patients and the implementation of a GFD would need to be conducted, but it appears to be a viable pathway to improving the quality of life and health of people struggling with CD and MDD. Therefore, probiotics, micronutrients, macronutrients, and vitamin supplements are recommended to reduce the risk of MDD, given that they may alleviate the symptoms of both these disease entities. In turn, in patients with MDD, it is worth considering testing for CD.

Is vitamin D supplementation program in Iranian schools effective in reducing adolescent depressive symptoms? Cost effectiveness study

PURPOSE

We aimed to assess the cost-effectiveness of the vitamin D supplementation program in Iranian adolescents reducing adolescent depressive Symptoms.

METHODS

In the current cost-effectiveness analysis, the viewpoint of Iran's Ministry of Health was selected. The target population was 1,519,762 Iranian high school students (733,657 girls and 786,105 boys). The total costs of the vitamin D supplementations program were based on the reports of the Nutrition Improvement Office of Iran's Ministry of Health and were adjusted to 2018. The variable of Quality-Adjusted Life Years (QALYs) was considered a suitable variable for estimating the effectiveness of vitamin D supplementation. We chose one year as the time horizon. A decision tree model was constructed in TreeAge Pro. The results of the cost-effectiveness analysis were reported in term of the Incremental Cost-Effectiveness Ratio (ICER).

RESULTS

The results of our study showed that the estimated cost per QALY gained of the vitamin D supplementation program is equal to 1528.6676 $, which indicates that vitamin D supplementation in adolescents(11-18Y) is a cost-effective and a dominant strategy in preventing depression through the cost-saving and QALYs increment compared to the no intervention. Sensitivity analysis showed that the possible variations in vitamin D supplement costs could not alter the results, and vitamin D supplementation may be a predominant and cost-effective strategy to prevent adulthood depression with a 100% probability.

CONCLUSION

The national program of vitamin D supplementation among Iranian adolescents was a cost-efficient strategy reducing adolescent depressive Symptoms through the cost-saving and QALYs increment compared to the no intervention.

Treatment-resistant depression in children and adolescents

Major depressive disorder (MDD) in children and adolescents is a significant health problem, causing profound impairments in social, academic, and family functioning and substantial morbidity and mortality. Up to 15% of children and adolescents suffer from MDD, and a proportion, around 30 to 40% of them, failed to respond to initial selective serotonin reuptake inhibitor (SSRI) treatment. The only evidence-based recommendation is medication switching to another SSRI and augmentation with cognitive behavioral therapy. Newly developing treatment, including ketamine, transcranial magnetic stimulation, psychotherapy other than cognitive behavioral therapy, and combined pharmacotherapy with other interventions, requires further longitudinal controlled trials regarding efficacy and safety in this vulnerable population.

Need for Multidimensional and Multidisciplinary Management of Depressed Preadolescents and Adolescents: A Review of Randomized Controlled Trials on Oral Supplementations (Omega-3, Fish Oil, Vitamin D3)

(1) Background: Depression is a serious health problem with a high cost for public administration. Epidemiological studies report that one in five children have a mental disorder and about 50% of mental health problems exacerbate in childhood and adolescence. Moreover, the antidepressant efficacy in children and adolescents is poorly demonstrated and can cause severe behavioral adverse events such as suicidal ideation. (2) Methods: This systematic literature review examined oral supplementations (Omega-3, fish oil, Vitamin D₃) to treat depressed children, preadolescents, and adolescents. MEDLINE, Scopus, Embase, and PsycInfo were searched for articles published in the last five years. Six studies met the eligibility criteria. The inclusion criteria encompassed children, preadolescents, and adolescents, a diagnosis of depression, and an intervention of oral supplementations such as Omega-3, fish oil, and Vitamin D₃. (3) Results: Most of the studies demonstrated that dietary intervention provides positive outcomes in terms of depression symptoms. (4) Conclusions: Overall, the results demonstrate a positive effect for oral supplementation suggesting an increase intake of Omega-3, fish oil, and Vitamin D₃. However, only a few studies assess the effectiveness of diet recommendations, as a monotherapy or combined treatment, for the management of depression at developmental ages. Thus, there is still a need to further investigate these aspects and to look more specifically at adolescents and preadolescents.

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.

Efficacy and acceptability of vitamin D supplements for depressed patients: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

This systematic review and meta-analysis synthesized the evidence from randomized controlled trials comparing vitamin D and placebo in reducing depressive symptoms and contributing to all-cause dropout rates.

METHODS

Inclusion criteria were randomized controlled trials comparing reduced depression between depressed patients receiving vitamin D and those receiving placebo. We searched PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials through January 2022.

RESULTS

Eighteen trials (1980 participants, median age 39 y) were included in the meta-analysis. Vitamin D supplements were significantly superior to placebo in reducing depression (standardized mean difference = -0.49; 95% confidence interval [CI], -0.75 to -0.23; I² = 81%). Depressed adults (standardized mean difference = -0.70; 95% CI, -1.09 to -0.31) responded to vitamin D significantly better than children and adolescents (standardized mean difference = 0.10; 95% CI -0.27 to 0.47). Vitamin D administered as bolus doses (oral intermittent high doses or intramuscular single high dose) appeared to be more effective than that taken daily by the oral route (P < 0.01). Patients with more severe depression tended to respond better than those with less severity (P = 0.053). We found no moderating effect of concurrent antidepressant use, presence of major depressive disorder diagnosis, physical comorbidity, sex, duration and doses of vitamin D supplement, serum 25-hydroxyvitamin D levels at baseline, and changes in serum 25-hydroxyvitamin D levels in the vitamin D group. Dropout rates were indifferent between the groups (17 trials; risk ratio = 0.84; 95% CI, 0.6-1.16; I² = 0).

CONCLUSIONS

Heterogeneous data suggested that vitamin D supplements are effective and safe for depressed patients.

Effect of Vitamin D Supplementation on Depression in Adults: A Systematic Review of Randomized Controlled Trials (RCTs)

Vitamin D is a nutrient potentially beneficial in the treatment of depression. The study aimed to carry out a systematic review of the studies assessing the influence of vitamin D supplementation on depression within Randomized Controlled Trials (RCTs). The systematic review was prepared on the basis of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42020155779). The peer-reviewed studies available within PubMed or Web of Science databases until September 2021 were taken into account. The number of screened records was 8514, and 8 records were included. Two independent researchers conducted screening, including, reporting, and risk of bias assessment using the revised Cochrane risk-of-bias tool for randomized trials. The included studies presented a population of patients with major depressive disorders or general depression, as well as bipolar depression or postpartum depression. The majority of included studies were conducted for 8 weeks or 12 weeks, while one study was conducted for 6 months. Within the large number of included studies, a daily dose of 1500 IU, 1600 IU, or 2800 IU was applied, while within some studies, a vitamin D dose of 50,000 IU was applied weekly or biweekly. Among applied psychological measures of depression, there were various tools. In spite of the fact that the majority of included studies (five studies) supported the positive effect of vitamin D supplementation for the psychological measure of depression, for three studies the positive influence was not supported. A medium risk of bias was indicated for six studies, while a high risk of bias was defined for only two studies, due to deviations from the intended interventions and in measurement of the outcome, as well as for one study, also arising from the randomization process and due to missing outcome data. Based on conducted assessment, it should be emphasized that there are only four studies supporting the positive influence of vitamin D supplementation for the psychological measure of depression of the medium risk of bias, while two studies of a medium risk of bias did not support it. Taking this into account, the conducted systematic review is not a strong confirmation of the effectiveness of vitamin D supplementation in the treatment of depression.

Effect of vitamin D supplementation on the incidence and prognosis of depression: An updated meta-analysis based on randomized controlled trials

Background

There have been several controversies about the correlation between vitamin D and depression. This study aimed to investigate the relationship between vitamin D supplementation and the incidence and prognosis of depression and to analyze the latent effects of subgroups including population and supplement strategy.

Methods

A systematic search for articles before July 2021 in databases (PubMed, EMBASE, Web of Science, and the Cochrane Library) was conducted to investigate the effect of vitamin D supplementation on the incidence and prognosis of depression.

Results

This meta-analysis included 29 studies with 4,504 participants, indicating that the use of vitamin D was beneficial to a decline in the incidence of depression (SMD: −0.23) and improvement of depression treatment (SMD: −0.92). Subgroup analysis revealed that people with low vitamin D levels (<50 nmol/L) and females could notably benefit from vitamin D in both prevention and treatment of depression. The effects of vitamin D with a daily supplementary dose of >2,800 IU and intervention duration of ≥8 weeks were considered significant in both prevention and treatment analyses. Intervention duration ≤8 weeks was recognized as effective in the treatment group.

Conclusion

Our results demonstrate that vitamin D has a beneficial impact on both the incidence and the prognosis of depression. Whether suffering from depression or not, individuals with low vitamin D levels, dose >2,800 IU, intervention duration ≥8 weeks, and all females are most likely to benefit from vitamin D supplementation.

Vitamin D level in relation to depression symptoms during adolescence

BACKGROUND

This study aimed to investigate the association between 25-hydroxyvitamin D (25(OH)D) and depression symptoms among adolescents in Kuwait, a country with a high prevalence of vitamin D deficiency.

METHODS

A school based cross-sectional study was conducted on randomly selected 704 adolescents in middle schools. Data on depression symptoms were collected using the Children's Depression Inventory (CDI). Data on covariates were collected from the parents by self-administered questionnaire and from adolescents by face-to-face interview. Blood samples were analyzed in an accredited laboratory; and 25(OH)D was measured using liquid chromatography-tandem mass spectrometry.

RESULTS

Of 704 adolescents, 94 (13.35%; 95%CI:10.35-17.06%) had depression symptom (a score of 19 or more on the CDI). There was no significant difference in the median CDI score between different vitamin D status (p = 0.366). There was also no significant correlation between serum 25(OH)D concentration and CDI score (Spearman's rank correlation = 0.01; p = 0.825).There was no significant association between 25(OH)D and depression symptoms whether 25(OH)D was fitted as a continuous variable (crude odds ratio (OR) 0 .99 [95%CI: 0.98, 1.01], p = 0.458 and adjusted OR 1.01 [95%CI: 0.99, 1.02], p = 0.233), categorical variable as per acceptable cut-of points (crude analysis p = 0.376 and adjusted analysis p = 0.736), or categorical variable as quartiles (crude analysis p = 0.760 and adjusted analysis p = 0.549).

CONCLUSION

Vitamin D status does not seem to be associated with depression symptoms among adolescents in our setting. Nevertheless, it is important to have sufficient vitamin D levels during adolescence for several other health benefits.

Urinary Phytoestrogen Metabolites Positively Correlate with Serum 25(OH)D Level Based on National Health and Nutrition Examination Survey 2009-2010

Studies showed that vitamin D (25-hydroxyvitamin D) level in the human blood circulation could be affected by exogenous estrogen exposure. This study aims to explore the relationships between urinary phytoestrogens metabolites and serum total 25(OH)D in general population, urinary phytoestrogens metabolites (daidzein, enterodiol, enterolactone, equol, genistein and o-desmethylangolensin). Totally 2,609 adults ≥6 y old from the 2009-2010 National Health and Nutrition Examination Surveys (NHANES) were recruited into the cross-sectional analyses and information including demographic, socioeconomic, examinations and laboratory test were collected. All analyses were performed using Stata13.0, one-way analysis of variance and multivariable regression were utilised according to data characteristics, respectively. It showed that age, race, education level, body mass index (BMI), and sampling season had significant effects on serum 25(OH)D level (all p<0.001). In the whole population, urinary enterodiol and equol were significantly positively associated with serum total 25(OH)D level (β=0.86, 95%CI=0.08-1.65, p<0.05; β=1.68, 95%CI=0.91-2.45, p<0.001). Equol was also found significantly positively correlated with total 25(OH)D in both female and male separately (β=1.69, 95%CI=0.51-2.87, p<0.05; β=1.66, 95%CI=0.63-2.69, p<0.05). Phytoestrogen concentrations in the urinary and 25(OH)D levels in the serum had proved a positive correlation in our study, which provide theoretical basis and reference for the dietary nutrient intake in the population.

Is Vitamin D Important in Anxiety or Depression? What Is the Truth?

PURPOSE OF REVIEW

Depression and anxiety are mood disorders that affect health and therefore quality of life and increase the global burden of disease. One of the possible mechanisms in the pathophysiology of these mood disorders has been reported as oxidative stress and inflammation. In the light of this information, it is important to determine the relationship between antioxidant nutrients (such as vitamin D) and these diseases. There are points where the brain regions involved in the pathophysiology of depression and anxiety and vitamin D metabolism intersect.

RECENT FINDINGS

Low vitamin D levels are associated with increased symptoms of depression and anxiety. For this reason, vitamin D screening should be performed in the prevention and treatment planning of these mood disorders. Vitamin D, which has antioxidant properties and activity in brain tissue, is important for mood disorders preventions or treatments but serum levels must be followed.

Vitamin D Level Trajectories of Adolescent Patients with Anorexia Nervosa at Inpatient Admission, during Treatment, and at One Year Follow Up: Association with Depressive Symptoms

(1) Background: Evidence has accumulated that patients with anorexia nervosa (AN) are at higher risk for vitamin D deficiency than healthy controls. In epidemiologic studies, low 25(OH) vitamin D (25(OH)D) levels were associated with depression. This study analyzed the relationship between 25(OH)D serum levels in adolescent patients and AN and depressive symptoms over the course of treatment. (2) Methods: 25(OH)D levels and depressive symptoms were analyzed in 93 adolescent (in-)patients with AN from the Anorexia Nervosa Day patient versus Inpatient (ANDI) multicenter trial at clinic admission, discharge, and 1 year follow up. Mixed regression models were used to analyze the relationship between 25(OH)D levels and depressive symptoms assessed by the Beck Depression Inventory (BDI-II). (3) Results: Although mean 25(OH)D levels constantly remained in recommended ranges (≥50 nmol/L) during AN treatment, levels decreased from (in)patient admission to 1 year follow up. Levels of 25(OH)D were neither cross-sectionally, prospectively, nor longitudinally associated with the BDI-II score. (4) Conclusions: This study did not confirm that 25(OH)D levels are associated with depressive symptoms in patients with AN. However, increasing risks of vitamin D deficiency over the course of AN treatment indicate that clinicians should monitor 25(OH)D levels.

[Nutrition and mental health - how findings from genetic studies can support the identification of dietary effects]

Nutrition and mental health - how findings from genetic studies can support the identification of dietary effects Abstract. Introduction: Numerous studies indicate that dietary interventions could be an important approach to the prevention and treatment of mental disorders. However, conventional nutritional epidemiological approaches (e. g., observational studies and randomized controlled trials, RCTs) have specific limitations to consider when interpreting the results. This article examines whether genetic studies could help to establish a link between diet and the prevention of mental disorders. Furthermore, it examines whether it is possible to draw conclusions about causal relationships. Methods: This narrative review describes various approaches of genetic cross-phenotype studies and presents examples of their applications in nutritional psychiatry. In addition, it discusses specific requirements as well as the strengths and limitations of the respective approaches. Results: To date, in the context of nutritional psychiatry, genetic correlation analyses, look-up analyses, and Mendelian randomization (MR) studies have been used for genetic crossphenotype analyses. Genetic correlation and look-up analyses provide initial evidence of possible overlap between specific mental disorders and metabolic pathways or specific nutrients. MR studies are used for detailed analyses that aim to identify causal relationships. However, MR is based on specific assumptions that must be met and considered when results are interpreted. Conclusion: Genetic cross-phenotype analyses are a useful amendment to conventional nutritional epidemiological research. In particular, positive results from MR studies provide an important fundament for identifying and developing suitable dietary interventions, which in turn increases the chance of success upon testing in subsequent RCTs. Accordingly, genetic cross-phenotype analyses are important instruments for increasing the efficiency in nutritional psychiatric research.

The Effect of Omega-3 Fatty Acids on Thromboxane, Brain-Derived Neurotrophic Factor, Homocysteine, and Vitamin D in Depressive Children and Adolescents: Randomized Controlled Trial

In the DEPOXIN project, we have found that a high ratio of omega-6/omega-3 fatty acids (FA) is associated with worsening of depressive symptoms in children and adolescents with depressive disorder (DD) and that the 12-week omega-3 FA supplementation modulates DD symptoms. Here we present our results of the secondary outcomes: the levels of thromboxane (TXB), brain-derived neurotrophic factor (BDNF), homocysteine (HCy) and vitamin D. Fifty-eight patients were randomized into two arms. One group received a fish oil emulsion enriched with omega-3 FA, and the other received a sunflower oil emulsion containing omega-6 FA, for 12 weeks. Depressive symptoms were evaluated, using the Child's Depressive Inventory (CDI). The patients with DD had elevated TXB levels and decreased vitamin D levels, as compared to healthy controls. Both CDI and omega-6/omega-3 ratio correlated positively with TXB and negatively with BDNF at baseline. Compared to the omega-6 FA group, the supplementation with omega-3 FA for 12 weeks significantly reduced plasma TXB (p = 0.024) and increased BDNF (p = 0.011) levels. No changes in HCy and vitamin D were observed. Our results demonstrate the possible role of TXB and BDNF in the pathophysiology of DD and the benefits of omega-3 FA supplementation. The study was registered with the ISRCTN registry (ISRCTN81655012).

Does diet play a role in the prevention and management of depression among adolescents? A narrative review

BACKGROUND

Depression is one of the major causes of illness and disability, while suicide is the second leading cause of death amongst adolescents. Although many factors determine the mental health of an individual, diet has been gaining popularity as a key modifiable factor in the prevention and management of depression. Nutritional Psychiatry is an emerging field where researchers suggest that the food we consume influences our mental well-being.

AIM

This review aims to explore the significance of diet, nutrient deficiencies, imbalances, and unhealthy dietary patterns in the prevention and management of unipolar depression or major depressive disorder among adolescents.

METHODS

Electronic databases such as PubMed, Scopus, Google Scholar, Science Direct, and MEDLINE were searched using keywords such as "mental health," "depression," "adolescents," "diet," "dietary pattern," and pertinent articles (N = 68) were retrieved and reviewed.

RESULTS

The Mediterranean and traditional diets rich in complex carbohydrates, omega-3 fatty acids, B-group vitamins and several amino acids have shown negative correlation with the incidence of depression. On the other hand, Western dietary patterns (sweetened beverages, processed/ junk food, and foods rich in saturated fatty acids), along with low consumption of fruits and vegetables have been linked to an increased risk of depression among adolescents.

CONCLUSION

Dietary modification can prove to be a cost-effective strategy for the prevention and treatment of depression among adolescents. Diet and nutrition need to be recognized as key modifiable targets for the prevention of mental disorders and nutritional medicine should be considered as an integral part of psychiatric treatment.

Size Matters: The CAG Repeat Length of the Androgen Receptor Gene, Testosterone, and Male Adolescent Depression Severity

There is a distinct increase in the prevalence of depression with the onset of puberty. The role of peripubertal testosterone levels in boys in this context is insufficiently understood and may be modulated by a functional polymorphism of the androgen receptor gene (AR), a variable number of CAG repeats. Moreover, there is preliminary evidence that the relationship between testosterone, CAG repeat length, and the severity of depressive symptoms may differ between subclinical and overt depression, but this has neither been studied in a clinical sample of adolescents with depression nor compared between subclinical and overt depression in an adequately powered study. To investigate the relationship between free testosterone, CAG repeat length of the AR, depression status (subclinical vs. overt), and the severity of depressive symptoms, 118 boys treated as in- or daycare patients at a single psychiatric hospital were studied. Of these, 73 boys had at least mild depressive symptoms according to the Beck Depression Inventory-II (BDI-II > 13). Higher-order moderation analysis in the multiple regression framework revealed a constant relationship between free testosterone and depression severity irrespective of the number of CAG repeats in adolescents with a BDI-II score ≤ 13. In adolescents with a BDI-II score > 13, however, there was a significant negative relationship between free testosterone and BDI-II score in patients with <19 CAG repeats and a significant positive relationship regarding free testosterone and BDI-II score in those with more than 28 CAG repeats, even when considering important covariates. These results suggest that the effects of testosterone on mood in male adolescents with depression depend on the genetic make-up of the AR as well as on depression status. This complex relationship should be considered by future studies addressing mental health issues against an endocrine background and may, moreover, contribute to tailored treatment concepts in psychiatric medicine, especially in adults.

Lack of Evidence for a Relationship Between the Hypothalamus-Pituitary-Adrenal and the Hypothalamus-Pituitary-Thyroid Axis in Adolescent Depression

In adults with major depressive disorder (MDD), a dysfunction between the hypothalamus-pituitary-adrenal (HPA) and the hypothalamus-pituitary-thyroid (HPT) axis has been shown, but the interaction of both axes has not yet been studied in adolescent major depressive disorder (MDD). Data from 273 adolescents diagnosed with MDD from two single center cross-sectional studies were used for analysis. Serum levels of thyrotropin (TSH), free levothyroxine (fT4), and cortisol were determined as indicators of basal HPT and HPA axis functioning and compared to that of adolescent controls by t-tests. Quantile regression was employed in the sample of adolescents with MDD to investigate the relationship between both axes in the normal as well as the pathological range of cortisol levels, considering confounders of both axes. In adolescent MDD, cortisol levels and TSH levels were significantly elevated in comparison to controls (p = <.001, d = 1.35, large effect size, and p = <.001, d = 0.79, moderate effect size, respectively). There was a positive linear relationship between TSH and cortisol (p = .003, d = 0.25, small effect size) at the median of cortisol levels (50^th percentile). However, no relationship between TSH and cortisol was found in hypercortisolemia (cortisol levels at the 97.5^th percentile). These findings imply that HPT and HPA axis dysfunction is common in adolescents with MDD and that function of both axes is only loosely related. Moreover, the regulation of the HPA and HPT axis are likely subjected to age-related maturational adjustments since findings of this study differ from those reported in adults.