Yes, depression, Borderline personality disorder, bipolar disorder, and what not are big baskets where lots of different vegetables and fruit end up being together because according to someone they look close enough. DSM V makes for an amusing reading in human psychology (mostly of the psychiatrists who wrote it).
Funny how people can spend hours comparing two nearly identical cars, women, men, or chairs, but put together people who might have to in common only being depressed. I say being depressed because by now I come to accept that people without a biological depression just have no idea of what is happening to us. Their idiotic replies or suicide inducing support is often not malice or cruelty (“snap out of it,” “just walk and you will feel better” …), it is just that they try to understand from their angle and in their world those emotions just don’t exist. Can a human understand the tridimensional world of a sperm whale? I doubt it