ed of 23 items comprising four dimensions: (1) Physical functioning (e.g., "it's hard for me to run"), (2) Emotional functioning (e.g., "I feel angry"), (3) Social functioning (e.g., "other kids tease me"), and (4) School functioning (e.g., "I forget things"). Within both questionnaires, all items are scored on a five-point Likert-scale (0 = never to 4 = almost always). Each of the item scores is reversed and rescaled to a 0--100 scale: a score of 100 represents the best quality of life possible, a score of 0 the worst quality of life possible. Scale scores, as well as the sum score, are computed by adding together the different item scores and dividing this obtained score by the number of items answered. The questionnaire is applicable from the age of 5 (*N*~age~ = 0) and has sufficient to good validity and reliability ([@B52]). Five participants older than 5 years (1 patient and 4 siblings) did not complete the questionnaire. In the present study, Cronbach's alpha coefficients were 0.89 and 0.89, for patients and siblings, respectively.

The Maudsley Marital Questionnaire (MMQ; [@B2]) evaluates life in general (e.g., "Are you competent and successful at your job and your housework?") and the marital/sexual relationship (e.g., "How much are you committed to this marriage?"). The MMQ contains 20 items, each of which is rated on a 0--8 scale, with 0 representing the optimum response. Higher scores indicate more maladjustment. The MMQ has good reliability and validity and the psychometric qualities of the Dutch version were also found to be satisfactory ([@B2]; [@B38]). In the present study, the MMQ was not completed by single or divorced parents (*N* = 15; 9 mothers and 6 fathers) and only the subscale measuring general life satisfaction (i.e., satisfaction with life, household and social network) was taken into account, with a Cronbach's alpha reliability of 0.70 (mothers) and 0.72 (fathers).

Parents' scores on the MMQ were reversed, so for all participants (patients, siblings, mothers, fathers) higher scores (o