Eli Snyder1,2, Ryan Nakamura1,2, Miriya Ogawa1,3, Kaylin Bersamin1,4, Kyle Ishikawa2, Hyeong Jun Ahn 3, Enrique Carrazana, MD1, Kore Liow, MD1 Janette Abramowitz, MD1
2John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA.
3Department of Quantitative Health Sciences, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI4 Concussion and TBI Center, BRAIN Hawaii Pacific Neuroscience, Honolulu, HI, USA.
The Role of Pre- and Post-Injury Substance and Medication Use
Depression is frequently encountered in patients suffering from post-concussive syndrome (PCS) after mild traumatic brain injury (mTBI). Despite its prevalence, clinical strategies for predicting and managing post-concussion depression remain underdeveloped.
A recent retrospective study examined whether pre- and post-injury use of alcohol, tobacco, marijuana, and antidepressant medications are associated with increased risk of depression in individuals diagnosed with PCS .
Background
Post-concussion syndrome can persist long after a mild traumatic brain injury and often includes cognitive, emotional, and physical symptoms. Among these, depression represents a significant complication that can affect recovery and quality of life.
Understanding which patients are at higher risk may allow clinicians to intervene earlier and improve outcomes.
Study Objective
The objective of the study was to determine whether:
- Pre-injury substance use
- Post-injury substance use
- Antidepressant medication exposure
are associated with risk of depression in patients with post-concussion syndrome .
Methods
Researchers conducted a retrospective chart review of 297 patients diagnosed with PCS at a Honolulu neurology clinic between January 2020 and January 2023.
The study analyzed:
- Alcohol use
- Tobacco use
- Marijuana use
- Antidepressant medication use
Substance and medication use patterns were reviewed both before and after PCS diagnosis. Depression risk was evaluated using PHQ-2 scores .
Results
Prevalence of Depression Risk
- 31% of screened patients were identified as being at risk for depression following concussion.
Substance Use Findings
- Pre-injury tobacco use was significantly associated with greater depression risk.
- Marijuana use, both before and after concussion, was significantly associated with increased depression risk.
- Alcohol use did not emerge as a primary risk factor in comparison to tobacco and marijuana.
Antidepressant Use Findings
- Prior antidepressant use was a strong predictor of depression following concussion.
- Patients who discontinued antidepressants after injury were particularly at risk.
- Patients who co-used marijuana and antidepressants demonstrated the highest risk of depressive symptoms.
Clinical Implications
The findings identify several key risk factors for depression in PCS:
- Tobacco use
- Marijuana use
- Exposure to antidepressants prior to concussion
- Discontinuation of antidepressants after injury
These results highlight the importance of:
- Proactive screening for psychiatric symptoms in PCS patients
- Regular assessment of substance use
- Close monitoring of antidepressant adherence
Integrating these evaluations into neurorehabilitation care may help improve patient outcomes .
Multidisciplinary Approach
The study emphasizes the need for coordinated care involving:
- Neurology
- Physiatry
- Psychiatry
- Addiction specialists
Early identification and timely intervention may reduce the burden of depressive symptoms and improve recovery trajectories in patients with post-concussion syndrome.
Conclusion
Tobacco use, marijuana use, and prior antidepressant exposure—especially when antidepressants are discontinued after injury—are key predictors of depression risk in patients with PCS.
These findings support integrating psychiatric screening and substance-use assessment into routine post-concussion care. Future studies are needed to clarify the underlying mechanisms and determine optimal timing for intervention .
