Also, people are born predisposed, but I would hate to call that weak...Its a combination of environment and heredity....so if you are predisposed and have a better environment, its not that your weak, its that your lucky.
Depression is mostly biologically based but can be overcome with cognitive treatment, which would make me think that someone who has done so is exceptionally strong, rather than weak. It depends onhow you look at it, I guess. Is someone with asthma weak? I guess you could say yes...but why would you want to?