Revealing mistake: In the deflector dish scene when Worf chops the Borg's arm off with his mek'leth, the blade obviously doesn't even touch the Borg. (01:09:45)
Revealing mistake: Outside Engineering when Data twists the neck of one of the Borg, one of his sleeves comes up and you can see where the make-up on Brent Spiner's arm ends.
Answer: Troi says that future medical research is far more advanced and humanity has learned to work together and overcome many social problems without being specific. It's unknown how these conditions will be cured, but possibly through advanced gene therapy, new drugs, new surgical techniques, etc.
raywest ★