Date of Award

January 2013

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Michael Bracken



The reason why people recover slowly, or fail to recover completely by three months following mTBI is not fully understood. Minimal research has focused on pre-injury depression as a risk factor for recovery after injury. There has also been minimal investigation of the interaction of pre-injury depression with structural brain damage, such as those evidenced on neuroimaging. This pilot study will prospectively examine the effect of pre-injury depression levels among complicated and uncomplicated cases of mTBI.


Patients were recruited consecutively from the Emergency Room (ER) of Ben Taub General Hospital, in Houston, TX, from April 2000 to January 2004. Pre-injury depression was assessed using the Center for Epidemiological Studies-Depression Scale (CES-D) in the context of the month prior to injury. The outcome measures were assessed at approximately three months post-injury, and included affective/behavioral, physical, cognitive, and mental health components.


There were 186 (84%) that completed the follow-up interview at 3-months time. Using the CES-D total scores, the sample was categorized into 3 different levels of pre-injury depression, normal (CES-D <16), mild (CES-D 16-20), and moderate-severe (CES-D >20).

Compared to normal individuals, moderate-severely depressed mTBI patients report significantly worse symptoms on four of five measures. There was no association between mild depression and outcomes. The interaction of pre-injury depression level and complicated mTBI did not prove to be a significant predictor for any of the outcome measures.


The data does suggest that moderate-severe pre-injury depression does appear to be a risk factor for poor affective/behavioral, cognitive, physical, and mental health outcomes at three months compared to normal individuals. However, patients with mild pre-injury depression are not at the same increased risk for worse outcomes. The data did not support an interaction effect between pre-injury depression and complicated mTBI. The primary limitation of this study is assessing depression up to 30 days prior to injury, shortly after the injury. More research to address this question should be the focus of future studies.


This is an Open Access Thesis.

Open Access

This Article is Open Access