The population of the United States is aging, and an ever-increasing number of Americans are afflicted with neurodegenerative diseases. Because the pathogenesis of many of these diseases remains unknown, we must consider that environmental factors may play a causal role. This review provides an overview of the epidemiologic evidence for environmental etiologies for neurodegenerative diseases such as Alzheimer disease, Parkinson disease, parkinsonian syndromes (multiple system atrophy and progressive supranuclear palsy), and amyotrophic lateral sclerosis. Epidemiologic evidence for an association between environmental agents’ exposure and neurodegenerative diseases is not conclusive. However, there are indications that there may be causal links, and the need for more research is obvious.

Purpose of ReviewNon-suicidal self-injury (NSSI) is a common mental health threat among adolescents. This review aims to present the current literature on epidemiology, etiology, and therapeutic approaches with a focus on the period of adolescence.Recent FindingsNSSI is widespread among adolescents both in community as well as in clinical settings with lifetime prevalence rates between 17 and 60% in recent studies. It is influenced by multiple factors including social contagion, interpersonal stressors, neurobiological background, as well as emotional dysregulation and adverse experiences in childhood.SummaryThere is still a lack of studies regarding the psychotherapeutic as well as the psychopharmacological treatment of NSSI in adolescence. Furthermore, sufficient evidence for prevention programs is missing.

Background. Social media presents an important means for social interaction, especially among adolescents, with Instagram being the most popular platform in this age-group. Pictures and communication about non-suicidal self-injury (NSSI) can frequently be found on the internet.Methods. During 4 weeks in April 2016, n = 2826 (from n = 1154 accounts) pictures which directly depicted wounds on Instagram were investigated. Those pictures, associated comments, and user accounts were independently rated for content. Associations between characteristics of pictures and comments as well as weekly and daily trends of posting behavior were analyzed.Results. Most commonly, pictures depicted wounds caused by cutting on arms or legs and were rated as mild or moderate injuries. Pictures with increasing wound grades and those depicting multiple methods of NSSI generated elevated amounts of comments. While most comments were neutral or empathic with some offering help, few comments were hostile. Pictures were mainly posted in the evening hours, with a small peak in the early morning. While there was a slight peak of pictures being posted on Sundays, postings were rather evenly spread across the week.Conclusions. Pictures of NSSI are frequently posted on Instagram. Social reinforcement might play a role in the posting of more severe NSSI pictures. Social media platforms need to take appropriate measures for preventing online social contagion.