Supplementary Table 1. Prevalence of past-month anxiety by age from 2008 to 2018 (NSDUH, US persons ages 18 years and older)

Anxiety was quantified using a self-report measure of past-month anxiety. This variable was assessed with the item, how often did you feel nervous during the past 30 days” with five response options: all of the time, most of the time, some of the time, a little of the time, and none of the time. For these analyses, the five response options were recoded into two categories: no anxiety (i.e., none of the time, a little of the time, some of the time) and high anxiety (i.e., most of the time, all of the time). Only participants ages ≥18 were asked this question. To assess mental health treatment, respondents were asked to report whether they received any mental health treatment in the past year (yes/no).