Can stress cause formation of pimples? but research suggests that stress doesn't increase pimples.. please reply doctor.?

Stress alone is controversial -- possible effect, but as you say, probably not. OTOH, stress is often accompanied by things like altered diet and sleep deprivation, and maybe other factors, that might affect acne and other pimples. Very effective medications are available to reduce acne. If you have a severe case that might result in scarring, you definitely should be on treatment. Good luck.