Attention Time

My cat, Alcott, is about a year old now. Until the past month, he's been fine, and then randomly he's begun using the bathroom on my bed or the couch. It only happens if I leave him out-- if I leave him in the spare bedroom with the approproate toilet, he doesn't balk at it in the slightest; hops right up and does his buisness.
The vet says this is behavioral, and a friend said it might be that I'm not spending enough time with him. I work a lot, so this is entirely possible, and when I'm at home obviously I can't spend every waking hour playing with mouse toys. I try to do what I can and am trying to up what I'm already doing, but are there any solutions beyond "more playtime with Alcott"? Should I always drop everything and give him my attention when he asks for it? Should I try to keep him near me when I'm home? Ah! I don't want an unhappy kitty, and getting another cat just isn't an option at this time, but I also have to work so much so I can actually feed the cat I've got!

I would make sure to give him extra love. Does he sleep with you at night? When you are hanging out watching tv, give him love that sort of thing, i think there are some sprays you can get to stop them from peeing on things you dont want them too.

Try playing WITH him by dragging/wiggling a cord with knotted ends across the floor (and out of his sight) so he can play pounce (HUGE favorite cat game) and throwing little rolled up balls of foil for him to chase. Mouse toys are better with female cats who treat them like babies or prey (nice combo there :-)! but they bore the male cats.