When I say that some mental disorders might be perfectly normal given harsh environmental stressors, I'm not saying that the individual wouldn't be maladaptive to his environment (therefore undeserving of the application of a mental disorder), but rather that his response to the stressors is appropriate given his biological, emotional, psychological, etc. constitution -- his comprehensive self.
I'm not really sure what you're trying to demonstrate here. It honestly sounds like you're stating a profound grasp of the obvious. "Person A, given conditions B, will react in way C, given that person A is a human, and therefore likely to share basic human characteristics that other humans have." By appropriate I assume you're meaning "that which you'd expect of a human".
Though I should note that "maladaptive to one's environment" doesn't really apply to a mood disorder. That would be something like a personality disorder. Mood disorders aren't considered maladaptive to the context of one's environment but more to the context of one's happiness and physical health. I suppose if you developed a society where people walking around who were suicidal was preferable it wouldn't be an issue, but that doesn't seem like a useful distinction.
If this follows, this means that what determines a mental disorder depends entirely on the individual's environment with which he must adapt to, which means that each and every mental disorder in any manual you bring to the table is a mental disorder relative to the norming group's sociocultural context from which the normative data was taken in compiling a list of symptoms for each disorder. Put differently, mental disorders may be maladaptive by definition no matter which culture you're in, but what precipitates the disorder is a synthesis of individual and sociocultural factors.
I take what you mean by the last sentence is analogous to "delusional disorder may be maladaptive anywhere, but the symptoms to bring it along may be different, such as talking to the earth spirits in a Native American culture vs. Manhattan." So, I'm willing to more or less bite, since no one's yet put any televangelists in a mental ward yet. But that's the sort of thing that normally only applies to social things. Spanking and whipping your child is considered disordered here but is normal in other places (variance within the U.S. even).
Anyway, I think I see where you're going, and I'll try and address it by example.
ADHD is a developmental disorder. Basically, one's executive functioning doesn't develop as it should. Now, 50 years ago this simply wasn't a classified disorder... simply no one thought to see if some of those bratty kids were bratty for a reason. However, that doesn't change the fact that the person was disordered. In other words, their behaviour was maladaptive, it led to a decrease in their ability to function in the world, led to personal unhappiness and with a set treatment course could be ameliorated.
Basically, if a tree falls in a forest and no one is around to hear it... it's still fallen.
I also should note that disorders aren't just disorders in the context of their current state. A diagnosis also involves the development of the symptom course and the treatment used to ameliorate the disorder. By way of example, if someone comes in with schizophrenic symptoms but arrived at those symptoms by way of brain trauma, it isn't schizophrenia, even if the symptoms are exactly the same.
A rose by any other name. Some society may decide that some behaviour or other isn't a disorder, but that doesn't mean it's not extant in the person, only that they're choosing not to recognize it.
As for the rest: I'm not claiming that biological factors aren't hugely (if not exclusively) responsible for some mental disorders. Nor am I claiming that the DSM-IV-TR is the ubiquitous standard regarding mental disorders, but rather that even within the American context there is plenty of social and cultural diversity to put into question the legitimacy of using a single definitive manual for mental disorders (one that suffers from convenience sampling at that). This is reflected in survey literature that points to a majority of mental health practitioners who prefer an alternative to the DSM for diagnosis to fit their systemic and/or non-reductionistic diagnostic philosophies.
"The DSM needs either be somewhat general or else fail as a catch-all" isn't the same as "psychology is relative". While I freely grant that some disorders are in the context of one's environment (gender disorders come to mind) some frankly aren't (developmental disorders). I don't care where you are, ADHD is disordered. If you decide to turn the validity of disorders into "whether or not people care to recognize them" it's interesting, but otherwise useless.
Of course, I could be completely misunderstanding you, which is possible.
Regarding the claim under point 3 at the bottom, we're not considering whether a dissociative disorder is maladaptive or not, but whether or not it's reported worldwide. For this point, my source is admittedly a bit dated:
Kleinman, A. (1996). How is culture important for DSM-IV? In J.E. Mezzich, A. Kleinman, H. Fabrega, & D. L. Parron (Eds.), Culture and psychiatric diagnosis: A DSM-IV perspective (pp. 15-25). Washington, DC: American Psychiatric Press.
Which was cited in the text:
Eriksen, K., & Kress, V. E. (2005). Beyond the DSM story: Ethical quandaries, challenges, and best practices. Thousand Oaks, CA: Sage.
Judging by the citation I'm guessing that's from a book? Both of them? If it was a journal article I could get at least the abstract courtesy of my school's database, but I'm not going to get a book out, so I'll trust that you're not making this up.
