Cognitive Behavioural Therapy for Complicated Grief Reactions in Old Age

Aims of the study: 1. Evaluate the relative efficacy of an individually delivered versus group-based CBTgrief. 2. Evaluate the relative cost-effectiveness of an individually delivered versus group-based CBTgrief. 3. Examine the theoretically proposed treatment mediators of CBTgrief. 4. Explore loss-related and sociodemographic characteristics as possible moderators of intervention effects. Primary hypothesis: Group-based CBTgrief will show non-inferiority (i.e., equal efficacy) in reducing symptoms of PGD compared to individually delivered CBTgrief at six months follow-up. Secondary hypotheses: 1. Group-based CBTgrief will show non-inferiority (i.e., equal efficacy) in reducing symptoms of posttraumatic stress, depression, and anxiety compared to individually delivered CBTgrief at six months follow-up. 2. Group-based CBTgrief will be more cost-effective than individually delivered CBTgrief. 3. The observed effect of CBTgrief is mediated by changes in theoretically proposed maintaining mechanisms of complicated grief reactions (i.e. insufficient integration of the loss; negative loss-related cognitions; depressive and anxious avoidance). 4. Gender, level of education, age, baseline grief symptom level, type of loss, circumstances of the loss, time since loss, and number of additional losses will moderate the observed effects of CBTgrief. 5. Additional exploratory analyses include an additional matched comparison group, who have not received treatment in order to compare the effect of individual and group-based CBTgrief to a non-treatment group. This group will be extracted from a large-scale survey study: The Aarhus Bereavement Study (NCT03049007). Here, it is hypothesized that CBTgrief will have a statistically significant medium size effect on symptoms of PGD at six months follow-up compared to a matched comparison group, who did not receive treatment. Design: The present study is conducted as a randomized non-inferiority trial of individually delivered versus group-based CBTgrief using block randomization. Participants: Participants are recruited from the Danish National Center for Grief (DNCG), which is a Danish national organization that provide specialized psychological therapy to bereaved individuals who have lost a loved one. The therapists at the DNCG will screen and treat bereaved elderly people for complicated grief reactions with CBTgrief at their clinics in Odense and Copenhagen, Denmark. DNCG identifies participants through consultants, local practitioners, self-referral, and the DNCG grief support line. Assessment points: Participants will be assessed at pre-, mid-, and post-intervention as well as at three and six months follow-up (T1-T5). Additionally, data on healthcare utilization will be retrieved from the Danish national registers concerning use of health care services such as visits to general practitioners, psychologists etc. Sample size: A group sample size of 2x64 will enable us to detect non-inferiority between individually delivered and group-based CBTgrief with a non-inferiority of -0.5 SD on the primary outcome, i.e. symptoms of PGD, and a statistical power of 0.80. The true difference is assumed to be 0.0 and the one-sided significance level (alpha) of the test is 0.025. Based on an estimated dropout rate of 20% the total number of participants needed to recruit is N=160 participants.