Social impairments are suggested as vulnerability markers for schizophrenia and bipolar disorder. Therefore. we investigated the development of social responsiveness and theory of mind (ToM) in children at familial high-risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP). This study is part of The Danish High Risk and Resilience Study. https://darthomes.shop/product-category/piggy-banks/