Epidemiologists looked at data from from 1999 to 2020 and noted that death rates due to poisonings, firearms, and all other injuries increased substantially in the U.S., many of them due to suicide attempts.
The demography analysis of 3,813,894 deaths collated by the National Center for Health Statistics due to non-natural causes was simplistic - age, sex, race, ethnicity, and belief about intent, then separating out criminal acts for things like gun deaths and if there was no clear intent of suicide, listing drug overdoses as accidental, while parsing motor vehicle injuries and falls as well.