A prospective study into change of vitamin D levels, depression and frailty among depressed older persons.

OBJECTIVES: While vitamin D is involved in frailty as well as depression, hardly any study has examined the course of vitamin D levels prospectively. The objective of this study is to examine whether a change of vitamin D in depressed older adults is associated with either depression course, course of frailty, or both. METHODS: The study population consisted of 232 of 378 older adults (60-93 years) with a DSM-IV defined depressive disorder participating in the Netherlands Study of Depression in Older persons, a prospective clinical cohort study. Baseline and 2-year follow-up data on depressive disorder (DSM-IV diagnosis), symptom severity (inventory of depressive symptoms), frailty phenotype (and its individual components) and vitamin D levels were obtained. Linear mixed models were used to study the association of change in vitamin D levels with depression course, course of frailty, and the combination. RESULTS: Vitamin D levels decreased from baseline to follow-up, independent from depression course. An increase in frailty was associated with a significantly sharper decrease of vitamin D levels over time. Post hoc analyses showed that this association with frailty might be driven by an increase of exhaustion over time and counteracted by an increase in walking speed. CONCLUSIONS: Our findings generate the hypothesis that vitamin D supplementation in late-life depression may improve frailty, which may partly explain inconsistent findings of randomised controlled trials evaluating the effect of vitamin D for depression. We advocate to consider frailty (components) as an outcome in future supplementation trials in late-life depression.

Clinical characteristics of late-life depression predicting mortality.

OBJECTIVE: Depression has been associated with increased mortality rates, and modifying mechanisms have not yet been elucidated. We examined whether specific subtypes or characteristics of late-life depression predict mortality. METHODS: A cohort study including 378 depressed older patients according to DSM-IV criteria and 132 never depressed comparisons. The predictive value of depression subtypes and characteristics on the six-year mortality rate, as well as their interaction with somatic disease burden and antidepressant drug use, were studied by Cox proportional hazard analysis adjusted for demographic and lifestyle characteristics. RESULTS: Depressed persons had a higher mortality risk than non-depressed comparisons (HR = 2.95 [95% CI: 1.41-6.16], p = .004), which lost significance after adjustment for age, sex, education, smoking, alcohol, physical activity, number of prescribed medications and somatic comorbidity. Regarding depression subtypes and characteristics, only minor depression was associated with a higher mortality risk when adjusted for confounders (HR = 6.59 [95% CI: 1.79-24.2], p = .005). CONCLUSIONS: Increased mortality rates of depressed older persons seem best explained by unhealthy lifestyle characteristics and multiple drug prescriptions. The high mortality rate in minor depression, independent of these factors, might point to another, yet unknown, pathway towards mortality for this depression subtype. An explanation might be that minor depression in later life reflects depressive symptoms due to underlying aging-related processes, such as inflammation-based sickness behavior, frailty, and mild cognitive impairment, which have all been associated with increased mortality.

Effect of chronic somatic diseases on the course of late-life depression.

OBJECTIVE: To examine the influence of specific chronic somatic diseases and overall somatic diseases burden on the course of depression in older persons. METHODS: This was a prospective cohort study with a 2-year follow-up. Participants were depressed persons (n = 285) from the Netherlands Study of Depression in Older Persons. The presence of chronic somatic diseases was based on self-report. Diagnosis of depression was assessed with the Composite International Diagnostic Interview, and severity of depression was measured with the Inventory of Depressive Symptomatology Self-report. RESULTS: Cardiovascular diseases (odds ratio [OR] = 1.67, 95% confidence interval [CI] = 1.02-2.72, p = 0.041), musculoskeletal diseases (OR = 1.71, 95% CI = 1.04-2.80, p = 0.034), and the number of chronic somatic diseases (OR = 1.37, 95% CI = 1.16-1.63, p < 0.001) were associated with having a depressive disorder at 2-year follow-up. Furthermore, chronic non-specific lung diseases, cardiovascular diseases, musculoskeletal diseases, cancer, or cumulative somatic disease burden were associated with a chronic course of depression. CONCLUSIONS: Somatic disease burden is associated with a poor course of late-life depression. The course of late-life depression is particularly unfavorable in the presence of chronic non-specific lung diseases, cardiovascular diseases, musculoskeletal diseases, and cancer. Copyright © 2016 John Wiley & Sons, Ltd.

Adverse health outcomes in vitamin D supplementation trials for depression: A systematic review.

BACKGROUND: Vitamin D deficiency is a universal risk factor for adverse health outcomes. Since depression is consistently associated with low vitamin D levels as well as several adverse health outcomes, vitamin D supplementation may be especially relevant for depressed persons. This review examines the potential benefits of vitamin D for (somatic) health outcomes in randomised controlled supplementation trials for depression. METHOD: Systematic literature search to assess whether adverse health outcomes, such as frailty, falls, or cognitive functioning, were included in vitamin D supplementation trials for depression, and whether these outcomes were affected by supplementation. The revised Cochrane tool for assessing risk of bias in randomised trials was used. RESULTS: Thirty-one trials were included. Adverse health outcomes were considered in five studies. Two studies reported some beneficial effect on an adverse health outcome. CONCLUSIONS AND IMPLICATIONS: While depressed persons are at increased risk of vitamin D deficiency, supplementation trials hardly addressed the common negative health consequences of low vitamin D levels as secondary outcome measures. Well-designed trials of the effects of vitamin D supplementation in late-life depression should explore whether adverse health outcomes can be prevented or stabilised, and whether depression benefits from this improvement.