Adult siblings of people with and without intellectual and developmental disabilities: Sibling relationship attitudes and psychosocial outcomes.

There is still little research on the relationships between adults with intellectual and developmental disabilities and their typically-developing siblings, despite the importance of these ties for siblings' psychological well-being, especially in terms of depression, anxiety, and life satisfaction. In this study, the sibling relationship attitudes of adult siblings of people with (N = 133) and without (N = 140) intellectual and developmental disabilities were explored. Feelings, behaviors, and thoughts related to sibling relationships were measured using the Lifespan Sibling Relationship Scale; depression was measured using the Beck Depression Inventory-II; anxiety was measured using the Beck Anxiety Inventory; and life satisfaction was measured using the Satisfaction With Life Scale. Results indicate that higher levels of positive sibling relationship attitudes are negatively related to levels of depression and anxiety, and positively related to levels of life satisfaction. Furthermore, adult siblings of people with intellectual and developmental disabilities show less positive sibling relationship attitudes, higher levels of depression and anxiety, and lower levels of life satisfaction. Finally, group membership, indirectly through sibling relationship attitudes, was related to depressive and anxious symptoms, as well as to life satisfaction. Implications for future research and policies are discussed.