Firstborn and only children are likelier to develop anxiety and depression by the time they reach age 8 than children who are born second or later, according to a new review of almost 182,500 cases. Why it matters: The findings add another wrinkle to the still-unresolved debate over whether birth order affects childhood mental health.

A recent survey suggests misophonia is more prevalent than previously thought, and research from Europe suggests this condition shares genes with anxiety, depression, and PTSD. University of Amsterdam psychiatrist Dirk Smit and colleagues analyzed the genetic data from the Psychiatric Genomics Consortium,