Inclusion Criteria:  Diagnosed with congenital heart disease, defined as: "a gross structural abnormality of the heart and/or intra-thoracic great vessels that is actually or potentially of functional significance (including mild, moderate, and complex heart defects)" Aged 18 years of age or older at the moment of study inclusion Diagnosed with congenital heart disease before the age of 10 years Follow-up at an ACHD center or included in a national/regional registry Physical, cognitive, and language abilities to complete self-report questionnaires  Exclusion Criteria:  - Prior heart transplantation