Longitudinal course of behavioral and emotional problems in fragile X syndrome.

We describe a follow-up of a study of behavior and emotional problems in a cohort of young people with Fragile X syndrome over 7 years. The study demonstrates that there is substantial persistence of the overall level of behavior and emotional problems. However, there are changes in certain types of behavior. Scores on the "disruptive" subscale of the Developmental Behavior Checklist decline significantly, whereas those on the "antisocial" subscale increase significantly. These changes parallel those seen in a large epidemiological control sample of young people with intellectual disability due to other causes. Further, two individual behaviors that distinguished the Fragile X individuals from the control individuals in the original study, namely "shy" and "avoids eye contact," continue to do so 7 years later.