Could be wrong, but I think this might be about her ex boyfriend, Barrie. He's Scottish (hence the, "If you come back to America, just hit me up" line) and has suffered from depression for many years; Lana's song Black Beauty talks more about that which is why the lines "You said to a friend that you wish you were doing better" and "You've got the blues, changing like the weather, that's so like you" make sense, and it's known that Lana didn't exactly break up with him in the best way ("I shouldn't have done it" line makes sense here).
Could be wrong, but I think this might be about her ex boyfriend, Barrie. He's Scottish (hence the, "If you come back to America, just hit me up" line) and has suffered from depression for many years; Lana's song Black Beauty talks more about that which is why the lines "You said to a friend that you wish you were doing better" and "You've got the blues, changing like the weather, that's so like you" make sense, and it's known that Lana didn't exactly break up with him in the best way ("I shouldn't have done it" line makes sense here).