BackgroundDepression is a prevalent and disabling mental disorder that frequently co-occurs with a wide range of chronic conditions. Evidence has suggested that depression could be associated with excess all-cause mortality across different settings and populations, although the causality of these associations remains unclear.MethodsWe conducted an umbrella review of systematic reviews and meta-analyses of observational studies. PubMed, PsycINFO, and Embase electronic databases were searched through January 20, 2018. Systematic reviews and meta-analyses that investigated associations of depression and all-cause and cause-specific mortality were selected for the review. The evidence was graded as convincing, highly suggestive, suggestive, or weak based on quantitative criteria that included an assessment of heterogeneity, 95% prediction intervals, small-study effects, and excess significance bias.ResultsA total of 26 references providing 2 systematic reviews and data for 17 meta-analytic estimates met inclusion criteria (19 of them on all-cause mortality); data from 246 unique studies (N = 3,825,380) were synthesized. All 17 associations had P < 0.05 per random effects summary effects, but none of them met criteria for convincing evidence. Associations of depression and all-cause mortality in patients after acute myocardial infarction, in individuals with heart failure, in cancer patients as well as in samples from mixed settings met criteria for highly suggestive evidence. However, none of the associations remained supported by highly suggestive evidence in sensitivity analyses that considered studies employing structured diagnostic interviews. In addition, associations of depression and all-cause mortality in cancer and post-acute myocardial infarction samples were supported only by suggestive evidence when studies that tried to adjust for potential confounders were considered.ConclusionsEven though associations between depression and mortality have nominally significant results in all assessed settings and populations, the evidence becomes weaker when focusing on studies that used structured interviews and those that tried to adjust for potential confounders. A causal effect of depression on all-cause and cause-specific mortality remains unproven, and thus interventions targeting depression are not expected to result in lower mortality rates at least based on current evidence from observational studies.Electronic supplementary materialThe online version of this article (10.1186/s12916-018-1101-z) contains supplementary material, which is available to authorized users.

IMPORTANCE Previous studies suggest that depression and anxiety are common in patients with hidradenitis suppurativa (HS), more so than other dermatological conditions. Yet, to the authors' knowledge, no previous systematic review or meta-analysis has estimated the prevalence or odds ratio (OR) for those psychiatric comorbidities in this population. OBJECTIVE To assess the prevalence and odds for depression and anxiety in patients with HS. DATA SOURCES From July 25 to September 30, 2018, observational studies investigating the prevalence and odds for depression and anxiety in adults with HS were systematically searched without language restriction from the inception of each database to July 25, 2018, in PubMed/MEDLINE, Embase, and PsycINFO databases. Searches used various configurations of the terms hidradenitis suppurativa; acne inversa; depressive disorder; depression; anxiety; anxiety disorders; phobia, social; suicide; and suicide, attempted. In addition, the reference lists of included references were screened manually. STUDY SELECTION Two investigators independently screened references that measured prevalence rates and odds for depressive and anxiety symptoms in patients with HS. Of 136 unique references, 10 ultimately met inclusion criteria. DATA EXTRACTION AND SYNTHESIS Relevant data were extracted from eligible references. Authors were contacted to provide further information when necessary. Methodological quality of included studies was assessed through a modified version of the Newcastle-Ottawa Scale. Random-effects models were used to synthesize available evidence. MAIN OUTCOMES AND MEASURES Prevalence rates and ORs for depression and anxiety in adults with HS were the primary outcome measures. Heterogeneity across studies was assessed with the I 2 statistic. Sources of heterogeneity were explored through subgroup and meta-regression analyses. RESULTS Ten studies comprising 40 307 participants with HS met inclusion criteria. The overall prevalence of depression was 16.9% (95% CI, 9.9%-27.2%). Heterogeneity was large. In the subgroup of studies that considered a clinical criteria-based diagnosis of depression, the prevalence of depression was 11.9% (95% CI, 4.9%-26.2%), compared with 26.8% (95% CI, 20.4%-34.5%) in studies that used a screening instrument. The methodological quality of included studies moderated those findings. The OR for depression in individuals with HS compared with individuals without HS was 1.84 (95% CI, 1.57-2.15). The prevalence of anxiety was 4.9% (95% CI, 1.7%-13.2%); there were insufficient data to determine an odds ratio for anxiety in persons with HS because 2 studies included a comparison group. CONCLUSIONS AND RELEVANCE This systematic review and meta-analysis indicates that depression and anxiety are common comorbid conditions in patients with HS. Results suggest that the development of strategies to recognize and treat those psychiatric comorbidities in patients with HS is warranted.

Objective. Symptoms of psychological distress, including anxiety and depressive symptoms, and illness perceptions are important in determining outcome in patients with rheumatic disease. We aimed to compare psychological distress in psoriatic arthritis (PsA) and rheumatoid arthritis (RA) and to test whether the association between psychological variables and health-related quality of life (HRQOL) was similar in the 2 forms of arthritis. Methods. In 83 PsA patients and 199 RA patients, we used the Patient Health Questionnaire 9 (PHQ-9), the Symptom Checklist-90-Revised, and the Brief Illness Perception Questionnaire to assess psychological variables and the World Health Organization Quality of Life Instrument, Short Form to assess HRQOL. We used hierarchical regression analysis to determine the associations between psychological variables and HRQOL after adjusting for demographic variables and disease parameters. Results. The prevalence of moderate to severe levels of depressive symptoms (PHQ-9 score >10) was 21.7% in PsA patients, 25.1% in RA patients, and 36.7% in those PsA patients with polyarthritis. After adjustment for severity of disease and pain, anxiety (␤ ‫؍‬ ؊0.28) and concern about bodily symptoms attributed to the illness (␤ ‫؍‬ ؊0.33) were independent correlates of physical HRQOL in PsA. In RA, depressive symptoms (␤ ‫؍‬ ؊0.29) and concern about the consequences of the arthritis (␤ ‫؍‬ ؊0.27) were independent correlates of physical HRQOL. Conclusion. These findings suggest strongly that psychological factors are important correlates of HRQOL in PsA as well as in RA. Attention to patients' anxiety and their concern about numerous bodily symptoms attributed to the illness may enable rheumatologists to identify and manage treatable aspects of HRQOL in PsA.

The literature on non-genetic peripheral biomarkers for major mental disorders is broad, with conflicting results. An umbrella review of meta-analyses of non-genetic peripheral biomarkers for Alzheimer's disease, autism spectrum disorder, bipolar disorder (BD), major depressive disorder, and schizophrenia, including first-episode psychosis. We included meta-analyses that compared alterations in peripheral biomarkers between participants with mental disorders to controls (i.e., between-group meta-analyses) and that assessed biomarkers after treatment (i.e., withingroup meta-analyses). Evidence for association was hierarchically graded using a priori defined criteria against several biases. The Assessment of Multiple Systematic Reviews (AMSTAR) instrument was used to investigate study quality. 1161 references were screened. 110 met inclusion criteria, relating to 359 meta-analytic estimates and 733,316 measurements, on 162 different biomarkers. Only two estimates met a priori defined criteria for convincing evidence (elevated awakening cortisol levels in euthymic BD participants relative to controls and decreased pyridoxal levels in participants with schizophrenia relative to controls). Of 42 estimates which met criteria for highly suggestive evidence only five biomarker aberrations occurred in more than one disorder. Only 15 meta-analyses had a power >0.8 to detect a small effect size, and most (81.9%) meta-analyses had high heterogeneity. Although some associations met criteria for either convincing or highly suggestive evidence, overall the vast literature of peripheral biomarkers for major mental disorders is affected by bias and is underpowered. No convincing evidence supported the existence of a transdiagnostic biomarker. Adequately powered and methodologically sound future large collaborative studies are warranted.

Disturbed sleep is common in chronic obstructive pulmonary disease (COPD). Conventional hypnotics worsen nocturnal hypoxemia and, in severe cases, can lead to respiratory failure. Exogenous melatonin has somnogenic properties in normal subjects and can improve sleep in several clinical conditions. This randomized, double-blind, placebo-controlled study was carried out to determine the effects of melatonin on sleep in COPD. Thirty consecutive patients with moderate to very severe COPD were initially recruited for the study. None of the participants had a history of disease exacerbation 4 weeks prior to the study, obstructive sleep apnea, mental disorders, current use of oral steroids, methylxanthines or hypnotic-sedative medication, nocturnal oxygen therapy, and shift work. Patients received 3 mg melatonin (N = 12) or placebo (N = 13), orally in a single dose, 1 h before bedtime for 21 consecutive days. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI) and daytime sleepiness was measured by the Epworth Sleepiness Scale. Pulmonary function and functional exercise level were assessed by spirometry and the 6-min walk test, respectively. Twenty-five patients completed the study protocol and were included in the final analysis. Melatonin treatment significantly improved global PSQI scores (P = 0.012), particularly sleep latency (P = 0.008) and sleep duration (P = 0.046). No differences in daytime sleepiness, lung function and functional exercise level were observed. We conclude that melatonin can improve sleep in COPD. Further long-term studies involving larger number of patients are needed before melatonin can be safely recommended for the management of sleep disturbances in these patients.