Although children with Down's syndrome (DS) are at lower risk for psychopathology than others with intellectual disability, they do show more problems than typically developing children. However, age-related trends in these problems remain unclear.
The present authors examined age-related changes in the maladaptive behaviours of 211 children and adolescents with DS aged between 4 and 19 years (mean = 9.74 years). Most participants (n = 180) were recruited from families residing in the greater Los Angeles area, California, USA, while a minority (n = 31) were patients from a clinic specializing in the psychiatric management of people with DS. The participants were divided into four age groups: (1) 4–6 years, (2) 7–9 years, (3) 10–13 years and (4) 14–19 years.
Externalizing behaviours were lower across both the community and clinic samples, while internalizing behaviours were significantly higher in older adolescents aged between 14 and 19 years. Increases were found in withdrawal, seen in 63% of community-based adolescents, and 75% of clinic adolescents.
Older adolescents with DS may show decreased externalizing symptoms and subtle increases in withdrawal. Possible relationships are discussed between these shifts and increased risks of later-onset depression and Alzheimer's disease in adults with DS.