No one here has mentioned anything about what constitutes depression.
The point has been made that an arahant can experience physical pain. This is clearly a feeling that has no other implications beyond itself as the arahant has no aversion or negativity towards it.
What then are we calling depression? Is it merely a low feeling in the mind? This is NOT what is meant by depression. It usually means negativity towards oneself and towards others resulting in lack of interest. Either a mental thought like a dagger, "I hate myself," or a weight, like, "Why must I get out of bed, ugahhuhh," due to a heavy mind. Heavy with what? One with metta "wakes easily, sleeps easily, and dreams no evil dreams."
Ask yourself, if you had literally no hatred, could you be depressed? It would simply be a feeling in the mind, not real depression, if you think so.