A seasonal suicide peak in spring is highly replicated, but its specific cause is unknown. We reviewed the literature on suicide risk factors which can be associated with seasonal variation of suicide rates, assessing published articles from 1979 to 2011. Such risk factors include environmental determinants, including physical, chemical, and biological factors. We also summarized the influence of potential demographic and clinical characteristics such as age, gender, month of birth, socioeconomic status, methods of prior suicide attempt, and comorbid psychiatric and medical diseases. Comprehensive evaluation of risk factors which could be linked to the seasonal variation in suicide is important, not only to identify the major driving force for the seasonality of suicide, but also could lead to better suicide prevention in general.

Background: Use of hypnotics or anxiolytic drugs is common and various studies have reported increased mortality with hypnotics or anxiolytic use. Objective: To consolidate the evidence on mortality risk associated with hypnotics or anxiolytic use Methods: Major databases were searched through April 2014 for studies reporting mortality risk associated with hypnotics or anxiolytics use. A pooled hazard ratio with 95% confidence interval was estimated using random-effects model. Results: After screening 2188 articles, 25 studies (24 cohort, 1 case-control) enrolling 2,350,093 patients with 59% females (age 18–102 years) were included in the meta-analysis. Hypnotics or anxiolytic users had 43% higher risk of mortality than non-users (hazard ratio, 1.43; 95% confidence interval, [1.12, 1.84]). Eight studies reported risk estimates for each gender category and pooled results from these studies showed increased risk of mortality among men (hazard ratio = 1.60, 95% confidence interval = [1.29,1.99]) and women (hazard ratio = 1.68, 95% confidence interval = [1.38, 2.04]). Pooled results from 10 studies showed higher mortality among benzodiazepine users compared to non-users (hazard ratio = 1.60, 95% confidence interval = [1.03, 2.49]), while pooled results from five studies showed an increased risk of mortality with Z-drugs use although the effect could not reach statistical significance (hazard ratio = 1.73, 95% confidence interval = [0.95, 3.16]). Significant heterogeneity was observed in the analyses and the quality of included studies was good. Conclusion: This meta-analysis suggests that hypnotics or anxiolytics drugs use is associated with increased mortality and hence should be used with caution. Future studies focused on underlying mechanism of increased mortality with hypnotics or anxiolytics use are required.

Several lines of evidence suggest that schizophrenia, a severe mental illness characterized by delusions, hallucinations and thought disorder is associated with accelerated aging. The free radical (oxidative stress) theory of aging assumes that aging occurs as a result of damage to cell constituents and connective tissues by free radicals arising from oxygen-associated reactions. Schizophrenia has been associated with oxidative stress and chronic inflammation, both of which also appear to reciprocally induce each other in a positive feedback manner. The buildup of damaged macromolecules due to increased oxidative stress and failure of protein repair and maintenance systems is an indicator of aging both at the cellular and organismal level. When compared with age-matched healthy controls, schizophrenia patients have higher levels of markers of oxidative cellular damage such as protein carbonyls, products of lipid peroxidation and DNA hydroxylation. Potential confounders such as antipsychotic medication, smoking, socio-economic status and unhealthy lifestyle make it impossible to solely attribute the earlier onset of aging-related changes or oxidative stress to having a diagnosis of schizophrenia. Regardless of whether oxidative stress can be attributed solely to a diagnosis of schizophrenia or whether it is due to other factors associated with schizophrenia, the available evidence is in support of increased oxidative stress-induced cellular damage of macromolecules which may play a role in the phenomenon of accelerated aging presumed to be associated with schizophrenia.