Objectives Research on participatory medical decision making in children is still scarce. At the same time, there is broad consensus that involving young patients in decision making processes increases their adherence to medical procedures and reduces anxiety. Thus, this cross-sectional study's objective was to assess mothers', fathers', and children's evaluation of the child's decisional competence in the context of psychosomatic and psychiatric care and test for possible predictors of competence such as illness perception, health-related quality of life (HrQoL), socioeconomic status, gender, and age. Methods Fifty-four families (mother, father, child triads; total N = 143) completed self-report questionnaires. Age of the children ranged from 6-16 (M = 11.68, SD = 2.74; 43% female), and the majority had a diagnosis of hyperkinetic, depressive or pervasive developmental disorders. 80% of children were German native speakers, and 27-37% of parents had a university degree. Results Findings show that parents rate the consequences of the child's illness as more severe and report to understand it better than the child. Also, children indicate the proposed age for autonomous decision making as lower (13.55 years) than their parents (15.63, 16.58). Furthermore, age of child, mother, and father, HrQoL, illness coherence, and emotional illness representation emerged as significant predictors of the decisional competence subscales understanding, autonomy, decision making, and attitudes. Conclusions This study demonstrates the importance of considering all parties in shared decision making. Future research is challenged to more comprehensively evaluate contributing factors to achieve a more valid picture of children's decisional competence.

Background Parental beliefs about the cause of their child’s illness are thought to affect parents’ help-seeking behaviors, treatment decisions, and the child’s health outcomes. Yet, research on parental beliefs about disease causation is still scarce. While a small number of studies assesses parental cause attributions for singular disorders (e.g., neurodevelopmental disorders), no study has compared disorders with differing physical versus mental conditions or with mixed comorbidities in children and adolescents or their caregivers. Furthermore, most pediatric research suffers from a lack of data on fathers. Objective Hence, the objective of the current study was to test for possible differences in mothers’ and fathers’ perceptions about the etiology of their child’s illness. Methods Forty-two parent couples (overall N = 84) whose child had been diagnosed either with Attention Deficit Hyperactivity-Disorder (ADHD) or Autism Spectrum Disorder (ASD) (category “neurodevelopmental disorder”) or with a primary physical illness and a comorbid mental disorder, e.g. depression (category “psychosomatic disorder”) were asked to rate possible causes of their child’s illness using a modified version of the revised Illness Perception Questionnaire (IPQ) Cause scale. Results A two-way ANOVA showed that psychosomatic disorders were significantly more strongly attributed to be caused by medical and environmental stressors than neurodevelopmental disorders. A significant parent × illness category interaction revealed that this effect was more pronounced in fathers. Conclusions By providing first insights into parental beliefs about the etiology of their children’s neurodevelopmental versus psychosomatic disorders, this study paves ground for future research and tailored counseling of affected families.