%0 Randomized Controlled Trial %T Online cognitive behavioral therapy for prolonged grief after traumatic loss: a randomized waitlist-controlled trial. %A Lenferink LIM %A Eisma MC %A Buiter MY %A de Keijser J %A Boelen PA %J Cogn Behav Ther %V 52 %N 5 %D 2023 09 21 %M 37341432 %F 3.928 %R 10.1080/16506073.2023.2225744 %X Prolonged grief disorder, a condition characterized by severe, persistent, and disabling grief, is newly included in ICD-11 and DSM-5-TR. Prolonged grief symptoms can be effectively treated with face-to-face or internet-delivered cognitive behavioral therapy. Traumatic losses may elicit higher prevalence of severe grief reactions. While face-to-face cognitive behavioral therapy appears efficacious in treating prolonged grief symptoms in traumatically bereaved individuals, it is not yet clear if internet-based cognitive behavioral therapy is efficacious for this population. Therefore, we investigated the efficacy of a 12-week internet-delivered cognitive behavioral therapy for people bereaved through traffic accidents in a randomized waitlist-controlled trial (registration number: NL7497, Dutch Trial Register). Forty adults bereaved though a traffic accident were randomized to internet-based cognitive behavioral therapy (nā€‰=ā€‰19) or a waitlist control condition (nā€‰=ā€‰21). Prolonged grief, post-traumatic stress, and depression symptoms were assessed at baseline, post-treatment, and 8-week follow-up. Dropout in the treatment condition was relatively high (42%) compared to the control condition (19%). Nevertheless, multilevel analyses showed that internet-based cognitive behavioral therapy strongly reduced prolonged grief, post-traumatic stress, and depression symptoms relative to the control condition at post-treatment and follow-up. We conclude that internet-based cognitive behavioral therapy appears a promising treatment for traumatically bereaved adults.