By Richard Horgan Los Angeles (Knewz) — Total Brain wants everyone to know that its “Mental Health Index: U.S. Worker Edition” is not a survey or poll. Rather, it is an ongoing weekly assessment of the neuro-scientific brain signals of 500 working Americans. The most concerning finding of the latest chunk of assessments, spanning Nov. 29, 2021 to April 3, 2022, is that one in four workers screened at risk for post-traumatic stress disorder. That’s up 121 percent from when the same assessments were conducted before the pandemic. “High PTSD risk levels are a long-lingering effect of the pandemic…