The contribution of pre-existing depression to the acute cognitive sequelae of mild traumatic brain injury

Abstract

Primary objective: To determine the effect of pre-existing depression on the cognitive sequelae of mild traumatic brain injury (mTBI) within 24 hours of injury.

Research design: A 2 × 2 between-subjects design was used to examine the effect of depression and injury type on neuropsychological test performance. The independent variables were the injury type (mTBI or control) and the presence of depression (depressed or not depressed).

Methods and procedures: Participants who had sustained mTBI (30 with depression, 30 without depression) within the previous 24 hours and control participants (19 with depression, 30 without depression) were assessed on the Digit Symbol Substitution Test (DSS), Hopkins Verbal Learning Test (HVLT) and the Speed of Comprehension Test.

Results: Participants with mTBI performed worse than controls on the tests, particularly HVLT delayed recall and DSS total correct. Participants with depression did not perform worse than participants without depression. However, there was a significant univariate interaction for HVLT recognition, participants who had sustained mTBI and were classified in the depressed group exhibited worse recognition compared to mTBI participants without depression.

Conclusions: The results indicate that depression may interact with mTBI to impair word recognition during the acute phase after a head injury.

• Mild traumatic brain injury
• concussion
• depression
• verbal memory
• information processing speed