What killed Riley Christiansen? Bay Area teen’s suicide follows bout with COVID and starting college in pandemic lockdown

The day before Riley Christiansen took his life at Lookout Point, the scenic cliffs near Chico State University, the 18-year-old searched online for anything to explain his bewildering bouts of memory loss and why he felt so “down.”

“What to do if you start to talk less?” the usually affable college freshman from Clayton typed into a search engine on Nov. 8 and again the day of his death. “What to do if you are losing your personality?”

Two months earlier, Riley had...