Birgit Wagner, Laura Hofmann, Ulrike Maaß

• Background: The loss of a sibling can have a long-term impact on the mental and physical health of the surviving sibling throughout adolescence and later adulthood. Even though bereaved siblings can be identified as a high-risk group, evidence-based interventions for this bereavement group are still missing. Aim: To evaluate the treatment effects of an internet-based writing intervention for bereaved siblings aged 16-65 years. Design: A two-armed randomized controlled trial (DRKS00011514) compared the intervention to a waiting list control group. The 6-week intervention consisted of six structured writing assignments that were based on cognitive behavioral therapy, focusing on the specific situation of bereaved siblings. Setting/participants: Eighty-six bereaved siblings (loss >1 month ago, no severe psychiatric symptoms) were randomly allocated to the intervention group (n = 47) or the waiting list control group (n = 39). Primary outcomes were symptoms of prolonged grief disorder and depression; secondary outcomes wereBackground: The loss of a sibling can have a long-term impact on the mental and physical health of the surviving sibling throughout adolescence and later adulthood. Even though bereaved siblings can be identified as a high-risk group, evidence-based interventions for this bereavement group are still missing. Aim: To evaluate the treatment effects of an internet-based writing intervention for bereaved siblings aged 16-65 years. Design: A two-armed randomized controlled trial (DRKS00011514) compared the intervention to a waiting list control group. The 6-week intervention consisted of six structured writing assignments that were based on cognitive behavioral therapy, focusing on the specific situation of bereaved siblings. Setting/participants: Eighty-six bereaved siblings (loss >1 month ago, no severe psychiatric symptoms) were randomly allocated to the intervention group (n = 47) or the waiting list control group (n = 39). Primary outcomes were symptoms of prolonged grief disorder and depression; secondary outcomes were posttraumatic stress symptoms and survivor guilt. Results: Symptoms of depression and prolonged grief disorder improved significantly in the intention-to-treat analyses from pre-to post-measurement compared with the control group (g(Depression) = -0.62, g(Grief) = 0.33). In the intervention group, all primary and secondary outcomes decreased significantly from baseline to 12-month follow-up (gs = -0.38 to -1.04). A significant clinical change could be found for depression (34%) compared to the waitlist control group (10%). Conclusions: Bereaved siblings profited from this brief internet-based writing intervention in the short- and long-term. However, future research, such as dismantling studies, may help to further optimize the benefits of an intervention aimed at bereaved siblings.…