TORONTO – Scan the literature on mental health technologies, and you’ll find treatment apps for everything from depression to addiction. What you won’t find, said Claude Hariton, vice president and chief scientific officer at Quebec City-based Diamentis Inc., are tools to diagnose mental diseases. It’s a gap the company hopes to fill with Retinal Signal Processing and Analysis (RSPA), a tool just accepted into the U.S. FDA’s breakthrough devices program that diagnoses mental diseases from retinal signals in the eye.