Children are 71% more likely to develop mental health problems between the ages of 5-18 if the firstborn child in their family experienced adversity during their first 1,000 days, finds a new study led by Dr Shabeer Syed & Prof Ruth Gilbert @uclpophealthsci.bsky.social https://www.ucl.ac.uk/news/2025/feb/adverse-childhood-experiences-firstborns-associated-poor-mental-health-siblings