If you think your dog or cat is depressed or suffering from some form of mental disorder, you're probably right. As pet parents we have a bond with our pets that nobody else shares. We know our pets better than anybody else, which means we can usually empathetically understand many of the nuances of our companion animals' mental states.
This TED Talk is suggesting that there may be some scientific fact to our claims of experiencing the different emotions of our pets. It's still anthropomorphic in a sense to believe that our pets suffer from mental disorders, but there is evidence to prove there is some truth to that belief.
Animals do get depressed and do suffer from OCD, but their depression and OCD may not be exactly the same as ours. It is their version of what we know as mental disorders. But still, they do suffer from them, just as we suffer from our own.
The fact is, there are animals on anti-depressants and other drugs for mental disorders. We even test the effectiveness of our anti-depressants on depressed rats before they hit the market for our use! This is a very interesting talk.
Here are a few videos of examples of some pets displaying some mental disorders: