Male cat depression

Question
My male cat is 3 years old. We have been very very close during his life from the beginning. We went through a lot together. We lived in Colorado for two years and moved back home to Athens Greece where we live now. He's been very loyal. When I arrive home, he recognizes the sound of my motorcycle and runs to welcome me. I take him in my arms and rub my nose in his throat. Recently he stopped welcoming me, he is depressed, very distracted and closed off. He continues hanging out outdoors but now he will not respond to my calling him. He hides from me and I'm concerned that he might run away on me even though he has been neutered and he loves me. All his life he's been sleeping with me in bed and he loves me very much. Could he been thinking to escape the new situation that I might have imposed on him ever since I introduced in our household this new 3 month old male kitty? It's been since 9/26/'12 that the new cat was added to our little family of two (now three).

Answer
Cor,

I think that your kitty should see a veterinarian. When cats suddenly change their behaviour like this they are often sick. I believe that you need to rule out medical reasons for this sudden behavioural change prior to making the assumption that your kitty's behaviour is the result of your new kitten. If you have any further questions or concerns, please feel free to contact me again at any time - I'm more than happy to help in any way that I can.

Kind regards,

Ali