Mental illnesses carry a stigma many don't want put on them, which is why they won't seek help. There are extreme highs and lows in depression episodes much of the time, and they think going to Thailand might make them happy, with it's easy sex tourism reputation, along with the change, but wherever you go, there you are. They aren't nutters. Just hurting from genetics half of the time, especially in this type of extreme case, and some life events a precursor also. Loneliness, drugs and alcohol, losses, or illness. Going on vacation might help or hurry it along, depending on events, but it'll come eventually unless they seek help.