We have extremely limited information about BK's mental health status. It would not seem to me personally that BK suffers from schizophrenia, and time-wise, it is unlikely either. His VSS was described at the age when it would be unlikely to have a first break. Too early. To add to it, if his classmates' account of BK using drugs in adolescence is to be believed, then how does one discriminate between drug-induced psychosis (if BK showed psychotic simptoms) and organic mental illness? Very hard.
About VSS, i read some information as well, but it is a "syndrome", so the underlying conditions might be different for different people. JMO. I don't believe that we shall be able to understand what BK suffered from, without additional medical information. The array of treatment modalities mentioned for VSS might also hint at different origins of the condition in its sufferers.
Looking through the list of the medications prescribed for the condition, I suddenly thought, what if BK was on some psychoactive drug for years prescribed for his VSS, and did relatively well? After all, most reports about him in adult years mention some social issues, but he maintained a steady job, got Masters and was accepted to Ph.D. program. One thing that comes to mind is the story of BK applying for police internship with Pullman PD (link
Idaho murders: Bryan Kohberger applied for internship at Pullman Police Department in fall 2022). Makes me wonder if he stopped his medications before that? (He probably had to fill in some paperwork for application). This could have eventually caused a shift in thinking patterns. JMO, I don't have any information about his medical history.