The association of depression and all-cause and cause-specific mortality: an umbrella review of systematic reviews and meta-analyses

Background: Depression 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. Methods: We 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. Results: A 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. Conclusions: Even 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

Prospection and natural selection

Prospection refers to thinking about the future, a capacity that has become the subject of increasing research in recent years. Here we first distinguish basic prospection, such as associative learning, from more complex prospection commonly observed in humans, such as episodic foresight, the ability to imagine diverse future situations and organize current actions accordingly. We review recent studies on complex prospection in various contexts, such as decision-making, planning, deliberate practice, information gathering, and social coordination. Prospection appears to play many important roles in human survival and reproduction. Foreseeing threats and opportunities before they arise, for instance, drives attempts at avoiding future harm and obtaining future benefits, and recognizing the future utility of a solution turns it into an innovation, motivating refinement and dissemination. Although we do not know about the original contexts in which complex prospection evolved, it is increasingly clear through research on the emergence of these capacities in childhood and on related disorders in various clinical conditions, that limitations in prospection can have profound functional consequences

Adverse life events and the onset of anxiety disorders.

This study tested the hypothesis that adverse events are associated with increased risk of onset of anxiety disorders. Data from Waves 1 (N = 43,093; 2001-2002) and 2 (N = 34,653; 2004-2005) of the National Epidemiological Survey on Alcohol and Related Conditions (NESARC) were used to assess whether adverse events at baseline are associated with increased risk of anxiety disorder onset over three years of follow up. Sixty-six percent (SE: 1.0) of respondents with an anxiety disorder in the intervening period between Waves 1 and 2 had experienced an adverse life event in the year prior to the Wave 1 interview. In logistic regression models adjusted for sociodemographic and psychiatric characteristics, adverse life events at baseline were associated with anxiety disorder onset within the three-year follow up period. The pattern of association between adverse events and anxiety disorder onset was similar across sub-types, and injury, illness or death of family or close friends consistently had the strongest association with anxiety disorder onset. These findings suggest that adverse life events play a role in the onset of anxiety disorders

Social psychiatry and psychiatric epidemiology

Purpose: The purpose of this study was to perform a systematic review and meta-analysis of prospective cohort studies that examined the relationship between anxiety disorders, or clinically significant anxiety symptoms, at baseline and all-cause mortality at follow-up relative to control participants without clinically significant anxiety.Methods: PubMed, EMBASE, PsycInfo, and CINAHL were searched through July 2015, along with manual searches of published reviews and forward and backward snowball searches of included studies. Studies were excluded if anxiety was not defined with a standardized instrument, or if participants were followed-up for 1 year or less. The initial search yielded 7901 articles after the removal of duplicates, of which 328 underwent full-text screening.Results: Forty-two estimates from 36 articles were included in the meta-analysis with a total sample of 127,552 participants and over 11,573 deaths. The overall hazard ratio (HR) estimate of mortality in clinically anxious participants relative to controls was 1.09 (95 % CI 1.01–1.16); however, this was reduced after adjusting for publication bias (1.03; 95 % CI 0.95–1.13). There was no evidence of increased mortality risk among anxious participants derived from community samples (0.99; 95 % CI 0.96–1.02) and in studies that adjusted for a diagnosis of depression (1.01; 95 % CI 0.96–1.06).Conclusions: These findings suggest that positive associations in the literature are attributable to studies in smaller samples, comorbid depression (or other psychiatric conditions) among participants, and possible confounding in medical patient samples followed-up for short durations.</br

Anxiety: here and beyond

The future harbours the potential for myriad threats to the fitness of organisms, and many species prepare accordingly based on indicators of hazards. Here, we distinguish between defensive responses on the basis of sensed cues and those based on autocues generated by mental simulations of the future in humans. Whereas sensed threat cues usually induce specific responses with reference to particular features of the environment or generalized responses to protect against diffuse threats, autocues generated by mental simulations of the future enable strategic preparation for hazards that may not require an immediate response. The overlap of these mechanisms makes defence effective and versatile, yet can manifest as contemporary anxiety disorders in humans