Is it normal for cats to be severly depressed?

If your cat is behaving in a way which seems like depression to you, it's far more likely it has some physical ailment which you need to have checked out.

No. But seeing as they have only one expression and don’t speak English it’s hard to tell in the first place.

Yes cats get depressed but if so it's most likely for a reason such as an untreated illness or a lot of stress factors in the cats home environment.

Yes, I had a dog one time that had to go on prozac.

I've shared a house with cats for a long time.

I've seen stressed-out, anxious cats; I've seen thoroughly pissed-off cats; I've seen a lot of needy, attention-seeking cats. But I don't recall ever looking at a cat and suspecting it was depressed.

I suppose some might say that's just because I'm a non-emphatic dick who doesn't realise that all animals are people in furry coats, but I just don't see how a cat could possibly be depressed. Depression is about feeling that you're shit, your life is shit and the only thing that's going to happen in the future is that things will get even shittier. Cat's are incapable of the insight that makes such thoughts possible, and they live in the moment, not in the past or the future as we humans can do.

If you feel that your cat is depressed, I suspect you're either projecting or you're one of those people who believes the interior life of animals is as complex as that of humans.

I accept that it's possible animal psychology is more complicated than is commonly believed. I'm also aware that there's evidence that some bird species and a few large mammals might have a degree of consciousness and self-awareness. But all my experience with cats leaves me firmly convinced that they really just don't have the mental capacity necessary for those higher mental functions.