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.

Background  This study explores everyday social competence in the lives of persons with three genetic intellectual disability syndromes. Methods  Using parent reports on the Social and Activity Competence domains of Achenbach's Child Behavior Checklist (CBCL), socially competent behaviours were examined in 58 persons with Williams syndrome, 54 persons with Prader‐Willi syndrome, and 65 persons with Down's syndrome. Results  The Down's syndrome group showed the highest overall social competence scores, while individuals with Prader‐Willi syndrome fared worst in terms of their behaviour with others. The Williams syndrome group scored lowest in terms of skill with jobs and chores, and the Down's syndrome group showed the least skill in non‐sport activities. Regarding specific activities, musical activities were popular in both Williams syndrome and Down's syndrome, but more participants with Williams syndrome played musical instruments. Compared with the other groups, individuals with Prader‐Willi syndrome were five to 25 times more likely to play with jigsaw puzzles, and those with Williams syndrome were least likely to engage in any visual–spatial leisure activities. Age was found to be a positive correlate of social competence for the Williams and Down's syndrome groups, but not for the Prader‐Willi group. Conclusions  Implications are discussed for interventions and for future behavioural phenotype work.

In this two-part study, we assessed musical involvements in two samples of persons with Williams syndrome compared to others with mental retardation and also related musicality to anxiety and fears in Study 2. Relative to others with mental retardation, those with Williams syndrome were more likely to take music lessons, play an instrument, and have higher ratings of musical skills. In the Williams syndrome groups only, fewer externalizing symptoms were associated with listening to music, whereas less anxiety and fewer fears were associated with the frequency, duration, and skill in producing music as well as emotional responses to negatively toned music. Implications are discussed for future research on musical processing, musical interventions, and well-being in Williams syndrome and other groups.