> Homosexuality stopped being a mental illness in 1973 (or 1987 if you include sexual orientation disturbance), so that's not in the last 2 decades. This was a great success, there were studies that pointed at a marked decrease in suicides among people in same-sex relationship over time.

And while it's progress for psychology itself, and good for society, it's certainly not an achievement. People were killing themselves and being institutionalized because psychologists were calling them insane, and this stopped happening when psychology chose to stop calling them insane. I can't claim an important discovery in abuse prevention if I choose to stop abusing someone.