# Trends of incident adult Attention-deficit/hyperactivity disorder diagnoses before, during and after the pandemic provincial state of emergency in British Columbia (2013–2023): a population-based study

## TL;DR

This study tracks how adult ADHD diagnoses in British Columbia changed before, during, and after the pandemic, showing a significant increase during and after the pandemic.

## Contribution

The study provides population-based evidence of a sharp rise in adult ADHD diagnoses linked to pandemic and post-pandemic periods, with implications for mental health services.

## Key findings

- ADHD diagnosis rates increased from 8.8 to 19.2 per 100,000 monthly during the pandemic.
- Post-pandemic rates jumped to 34.8 per 100,000, with continued monthly growth.
- Differences in trends were observed by sex and substance use disorder history.

## Abstract

Emerging evidence indicates a potential rise in attention-deficit/hyperactivity disorder (ADHD) incidence worldwide and in British Columbia (BC) since the pandemic. Given the high comorbidity of ADHD with substance use disorder (SUD) and other mental disorders, understanding changes in ADHD diagnosis among adults is crucial for healthcare planning amid BC's drug poisoning (overdose) crisis. We aimed to report how rates of newly diagnosed adult ADHD changed before, during and after the pandemic by demographic variables and histories of SUD or mental disorders.

We conducted interrupted time series analyses on overall and stratified monthly incidence rates of ADHD diagnosis between Jan, 2013, and Nov, 2023 in BC, using data from linked population-based administrative databases.

The pre-pandemic average of newly diagnosed adult ADHD was 8.8 cases per 100,000 population monthly. During the pandemic (Mar, 2020–Jun, 2021), this rose to 19.2 driven by a 4.9% (95% confidence interval: [3.7, 6.2]) month-over-month increase. When the pandemic ended, the monthly rate jumped by 107.3% [68.5, 155.0] in Jul, 2021 and grew 1.5% [0.4, 2.7] per month thereafter, averaging 34.8 cases per 100,000 post-pandemic. Substantial differences in trends emerged when stratified by sex and SUD histories.

This exponential rise in adult ADHD may be explained by pandemic-related sociocultural changes and the broader societal evolution in mental health awareness in recent years and decades. This rise could foreshadow a potential increase in the population at risk of SUD, underscoring the urgent need for bidirectional integration of ADHD and SUD services.

We acknowledge the UBC Psychiatry Stimulus Grants Initiative.