I think my cat is depressed

Okay, hear me out. I don't know if depression in pets is a thing, but I've noticed something in my cat lately. Usually, she will greet me at the door, play with toys, and sleep on my lap. Now she just hides under the bed most of the day. She eats and uses the litter box, so physically she seems fine, but emotionally something's changed. I've moved nothing, changed nothing, and yet she seems completely withdrawn. Are these signs of depression, or am I overreacting?