Not "very," but they're both... cohesively unconscious enough that their quirks might seem incidental. But, I digress: I'm not any kind of doctor.
My mother has a lot anxiety/depression issues, (hopelessness, guilt, etc.) and my father has what may or may not be depression, but also what I've always called "a reliance on external things." He has what shrinks call an "addictive personality," which means he has an unusual tendency to rely on things (smoking, drinking) to cope with his emotions, in lieu of dealing with them internally.
Both my parents have VERY limited social lives and activities, (although they're not quite at my level ) particularly my father, who basically works and tinkers on his bike. Mind you, they both grew up socially normal and only became more like me after they got married and had me and my sister... heh.
So I guess in hindsight, a trained eye would have seen me coming.