An Examination of the Base Rates of Post-Concussion Symptoms: The Influence of Demographics and Depression

Abstract

Post-concussion syndrome (PCS) is a controversial constellation of cognitive, emotional, and physical symptoms that some patients experience following a mild traumatic brain injury or concussion. PCS-like symptoms are commonly found in individuals with depression, pain, and stress, as well as healthy individuals. This study investigated the base rate of PCS symptoms in a healthy sample of 96 participants and examined the relationship between these symptoms, depression, and sample demographics. PCS symptoms were assessed using the British-Columbia Post-Concussion Symptom Inventory. Depression was measured using the Beck Depression Inventory II. Results demonstrated that: The base rate of PCS was very high; there was a strong positive relationship between depression and PCS; and demographic characteristics were not related to PCS in this sample. These findings are broadly consistent with literature suggesting a significant role for non-neurological factors in the expression of PCS symptomatology. This study adds to the growing body of literature that calls for caution in the clinical interpretation of results from PCS symptom inventories.

Key words:

• base rates
• depression
• mild traumatic brain injury
• neuropsychology
• post-concussion syndrome

ACKNOWLEDGEMENTS

The Human Research Ethics Committee of Queensland University of Technology (approval no. 0700000965) approved all research documented in this report. The authors wish to acknowledge the generous assistance of Dr. Patricia Obst, statistics consultant, School of Psychology and Counseling, Queensland University of Technology, and Dr. Rael T. Lange who contributed to early discussions about this manuscript. Funding for this project was provided by the School of Psychology and Counseling, Queensland University of Technology.

Notes

Note. BC-PSI = British Columbia Post-Concussion Symptom Inventory.

Note. BC-PSI = British Columbia Post-Concussion Symptom Inventory Mild symptoms = BC-PSI total item score of 1or 2. Symptoms endorsed at this level are probably “subclinical” (Iverson & Lange, 2003). Moderate-to-severe symptoms = BC-PSI total item score of 3, 4, or 5. Symptoms endorsed at this level are probably “clinically meaningful” (Iverson & Lange, 2003).

Note. BC-PSI = British Columbia Post-Concussion Symptom Inventory. Depressed participants were those who scored 14 or above on the Beck Depression Inventory-II.