OBJECTIVES: The aims of this study were to assess the prevalence of unresolved grief in bereaved young adult siblings and examine possible contributing factors.

METHODS: The study was a Swedish population-based study of young adults who had lost a brother or sister to cancer, 2-9 years earlier. Of 240 eligible siblings, 174 (73%) completed a study-specific questionnaire. This study focused on whether the respondents had worked through their grief over the sibling's death and to what extent.

RESULTS: A majority (54%) of siblings stated that they had worked through their grief either 'not at all' or 'to some extent' at the time of investigation. In multiple regression analyses with unresolved grief as the dependent variable, 21% of the variance was explained by lack of social support and shorter time since loss.

CONCLUSION: The majority of bereaved young adults had not worked through their grief over the sibling's death. A small group of siblings reported that they had not worked through their grief at all, which may be an indicator of prolonged grief. Lack of social support and more recent loss were associated with not having worked through the grief over the sibling's death. Copyright © 2013 John Wiley & Sons, Ltd.