The outbreak of COVID-19 disrupted lives across the United States. Evidence shows that such a climate is deleterious to mental health and may increase demand for mental health services in emergency departments. The purpose of this study was to determine the difference in emergency department utilization for mental health diagnoses before and after the COVID-19 surge.

We conducted a cross-sectional study between January–August 2019 and January–August 2020 with emergency department encounter as the sampling unit. The primary outcome was the proportion of all emergency department encounters attributed to mental health. We performed chi-square analyses to evaluate the differences between 2019 and 2020.

We found that overall emergency department volume declined between 2019 and 2020, while the proportion attributable to mental health conditions increased (p < 0.01). Substance abuse, anxiety, and mood disorders accounted for nearly 90% of mental health diagnoses during both periods. When stratified by sex, substance abuse was the leading mental health diagnosis for males and anxiety and substance abuse disorders combined accounted for the largest proportion for females.

The emergency department is an important community resource for the identification and triage of mental health emergencies. This role is even more important during disasters and extended crises, making it imperative that emergency departments employ experienced mental health staff. This study provides a comparison of emergency department utilization for mental health diagnoses before the pandemic and during the spring 2020 surge and may serve as a useful guide for hospitals, health systems and communities in future planning.