Functional limitations and depression after traumatic brain injury: examination of the temporal relationship.

Objective: To examine the temporal relationship between self-reported injury-related functional limitations and depressive symptomatology after traumatic brain injury (TBI).
Design: A longitudinal cohort study with 3 evaluation points.
Setting: A level I trauma center.
Participants: Adolescents and adults (N=135) with complicated mild to severe TBI (72% had complicated mild injuries) who were recruited within 24 hours of injury and then completed the measure at all 3 time points.
Interventions: Not applicable.
Main Outcome Measures: Sickness Impact Profile and Center for Epidemiological Studies-Depression Scale.
Results: Individuals who reported more depressive symptomatology consistently endorsed more injury-related difficulties, showing the strong relationship between depression and perceived psychosocial functioning. Examination of these relationships over time revealed that increased depressive symptomatology follows higher levels of perceived injury-related changes but that reports of injury-related changes are not associated with earlier depression. These findings suggest a unidirectional temporal relationship between these variables.
Conclusions: Perceived changes in daily functioning appear to influence emotional well-being over time after TBI. However, depressive symptoms do not appear to negatively impact individuals' perception of later functioning. These results further our understanding of the complicated relationship between these variables and may have important implications for treatment of depression after TBI.