Again, many thanks, Eleos, Arimethea, and all others who replied!
A firnd of mine from Ukraine, a young Eastern Rite Catholic priest who is very interested in Orthodoxy, is in charge, specifically, for pastoral care of mentally disabled. Is there a similar pastoral responsibility in the Orthodox Church? He asked me to ask this forum, particularly, is there a notion in the Orthodox Church that mentally disabled need to grow spiritually and that the Church should help them become better citizens, or, rather, does the Orthodox Church treat them like mere "babies?" Where can one read bout these matters in the Orthodox literature?
The guy is really very friendly, there aren't any tricks in his questions as far as I can see. Thank you for your thoughts and references!