[Unimportant]
Personality disorders, mostly those belonging to cluster B, could be seen as evolutionary adaptive strategies. (Just to be clear, something is evolutionary adaptive if it increases inclusive fitness. It doesn’t matter if it makes you and others miserable, more or less creative, etc.)
Borderline personality disorder: Borderlines are manipulative and are able to extract large amounts of resources from their partners and “bind” them. Of course, this is an advantage, especially for females who want their fathers to provide resources for their offspring. Thus, it’s also not surprising that most borderlines are females.
Narcissistic personality disorder: Almost all cult-leaders and many leaders of states exhibited narcissism. Most cult-leaders sleep with extremely many women and would have fathered many offspring if birth control wasn’t available (which it wasn’t in the environment of evolutionary adaptiveness). E.g. think about Jim Jones (of Jonestown mass suicide fame), David Berg (Children of God).
Psychopathy/antisocial personality disorder: Very related to NPD and very similar advantages. Most psychopaths sleep with very many women. I think there are over one million living offspring of Ghinghis Khan.
It also makes sense that most psychopaths and most narcissists are males. It doesn’t make sense for women to be psychopaths because they can’t gain much from sleeping with hundreds of men and just abandoning their children.
Histrionic personality disorder: I guess it’s a bit more difficult to make a convincing case here, so I won’t even try.
Other personality disorders
Cluster A personality disorders make a lot less sense from an evolutionary perspective (except probably paranoid personality disorder). One could spin some stories for cluster C personality disorders but it seems a lot more difficult to convincingly make the case that they represent evolutionary adaptive strategies.