BackgroundRelatively few studies have examined the effects of layoffs on remaining workers, although the effects of layoffs and downsizing events may extend beyond those employees who lose their jobs.MethodsWe examined the effects of layoffs on mental healthcare utilisation and injury risk among workers at 30 US plants between 2003 and 2013. We defined layoffs as reductions in the hourly workforce of 20% or more at each plant. Using a difference-in-differences approach, we compared the change in outcomes during layoffs versus the same 3-month period 1 year previously, accounting for secular trends with control plants.ResultsOur study population included 15 502 workers and 7 layoff events between 2003 and 2013. Layoffs were associated with only minor decreases in injuries (−0.006, 95% CI −0.013 to 0.001). The probability of outpatient visits related to mental health increased by 1% during layoffs (0.010, 95% CI 0.003 to 0.017), and the probability of mental health-related prescriptions increased by 1.4% (0.014, 95% CI −0.0006 to 0.027). Among women, the increase in outpatient visits was more pronounced (0.017, 95% CI 0.003 to 0.031). Increased prescription utilisation appeared attributable primarily to opioid use (0.016, 95% CI 0.005 to 0.027).ConclusionOur results indicate an association between layoffs and remaining workers’ mental health and safety, although changes mental healthcare utilisation may reflect both changes in underlying mental health and changes in care-seeking. Future research on concordance of service utilisation and underlying health may yield valuable insight into the experiences employed workers in the wake of layoffs.