Diurnal cortisol and coping responses in close relatives of persons with acquired brain injury: a longitudinal mixed methods study

Objective: To examine the impact of having a close relative experience a severe brain injury.

Design: Six-month longitudinal mixed methods concurrent embedded study. Quantitative data provided the primary database and qualitative data provided the secondary source.

Methods: Assessment included psychosocial factors of perceived stress, traumatic stress symptoms, coping and social support in addition to salivary cortisol as a biological marker of stress. Written accounts of the experience were provided in response to an open-ended question. Participants composed 15 close relatives of adults with severe brain injury admitted to a specialist rehabilitation facility (mean age 49.4 years; SD 11.79). Assessments were conducted on admission, at 6 weeks, 3 months and 6 months post-admission.

Results: Quantitative data revealed high traumatic stress at admission, with a non-significant decline at follow-up. Diurnal cortisol output declined significantly from baseline to all follow-up assessments. Coping sub-scales of acceptance and religion were repeated associated with cortisol indices at baseline, 6 weeks, 3 months and 6 months follow-up. Qualitative data revealed two themes; 'relational impact' and 'passage of time'.

Conclusions: Findings offer the potential for effective and timely intervention in family members of persons with severe brain injury.