Ah, I think it is! Thank you! (You must have a better memory than me :P)

But yes, even in the case of mental illness there would still definitely be a looooot of issues to consider - is it ethical, it is really worth the potential benefits, which illnesses and to what degree would justify a Yeerk and which ones wouldn't, are the potential hosts capable of making informed consent, etc etc...not to mention the effect on the Yeerk themselves. Still, it is certainly something to think about.