Sure. It wasn't that long ago ('50s? '60s?) that homosexuality was defined by the preeminent psychological literature (DSM) as a mental disorder itself. We still use the DSM today, except it's been through a few revisions and homosexuality doesn't show in it anymore... but other controversial stuff does, like caffeineism.

The fact that these "disorders" and what constitutes them are often just voted on by professionals says a lot about their status as cultural phenomena. Some of these things are do have biological grounding, true—but others are based on conjecture, like the case of homosexuality. Our viewpoint of that has changed over the past few decades.

Even when it comes to something like depression, which we'd think would be more established by now, things change. It used to be the case that for situational depression, which is what might manifest if something bad happens in life to cause you to grieve, you had to show symptoms of depression for a year before qualifying for the disorder. That was considered the cutoff time for an abnormal amount of grieving. Then it was changed to six months. Then to three months. Now it's six weeks. That's right, if your son dies, you should just get over that in six weeks... otherwise, what you have is a disorder. This stuff is so flexible and ephemeral.

In another example, before the DSM, there used to be a disorder whose name literally translated into "lazy black man syndrome"... and the primary cure for that? Anoint the afflicted with oil, and work it in with a leather strap... i.e., oil 'im up and whip that slave until he do wut he told. Right. It's sort of similar to how labeling homosexuality as a disorder thereby enabled authority to treat that labeled person as they pleased, stripping them of rights, and comitting them involuntarily if so desired.

And before that, schizophrenia was a demon spirit in the head to be released with trepanation (Egypt), or celebrated communication the spirit world (Aztec shamans), or demonic possession to be cured with exorcism (Middle-Age Christianity), and so on. Depending on the culture, these things take on different meanings. Keep in mind that culture is always changing, and even today, we see some disorders defined in one culture (e.g. North America) that don't appear in other cultures (e.g. Japan). One might ask, Is the disorder sometimes something we define arbitrarily? The answer is yes, sometimes.