The transition from elementary to junior high school presents developmental challenges, particularly for students with neurodevelopmental traits. This study examined how autism, attention-deficit/hyperactivity disorder (ADHD) traits and effortful control (EC) were related to changes in mental health during this transition in a large Japanese community sample (N = 2,564). This longitudinal study used data from a community-based cohort of Japanese students and their parents/guardians (N = 2,692)….
