Hypoactive Sexual Desire Disorder (HSDD), particularly as it pertains to women's health. The disorder, which used to be called Inhibited Sexual Desire Disorder, is in the DSM-III-R and is characterized as a lack or absence of sexual fantasies and desire for sexual activity for some period of time. It's important to note that, for this to be regarded as a disorder, it must cause marked distress or interpersonal difficulties and not be better accounted for by another mental disorder (i.e. depression), a drug (legal or illegal), or some other medical condition.
But not everyone agrees that it's a genuine disorder. Part of the problem is that it's open to a wide interpretation, and no one really knows what's causing it. That said, a recent study suggests that women with persistently low sex drives have significant differences in brain activity, indicating that the problem is indeed neurologically based.
Regardless, some critics say that HSDD is yet another example of the medicalization of sexuality by the medical profession to define normal sexuality, including the pathologization of asexuality. Others point out that there are significant differences between male and female sexuality; level of desire is highly variable among women and there are some who are considered sexually functional who have no active desire for sex, but they can erotically respond well in contexts they find acceptable (what has been termed "responsive desire" as opposed to spontaneous desire). There are also relationships to consider; the focus on physiological factors may ignore the relationship context of sexuality despite the fact that these are often the cause of sexual problems. Lastly, there are yet others who contend that HSDD is an invention of Big Pharma who are now ready to cash in with the (potential) release of a female Viagra-like pill.
Undeniably, these criticisms address some valid concerns—but they're largely missing the point. If a woman feels that her libido is low, and she has the means with which to achieve a desired level of sexual responsiveness (i.e. she wants to 'function' in a particular way), then it can be genuinely classified as a disorder.
Admittedly, "disorder" may be too strong a term, but it's a good example of how an enhancement eventually becomes a therapy. Let's suppose for a moment that HSDD is pure fiction and that female sexuality is largely operating within normal bounds. Now, thanks to the marvels of modern medical science, we can tweak libido such that a more desirable state is achieved. Once such an intervention hits the market and becomes normalized across groups, then its absence can be characterized, for all intents and purposes, as the cause of a dysfunction. It has become a pathology.
That's how enhancement works, and that's why the whole therapy versus enhancement debate is mostly useless. What we consider normal human functioning today is not necessarily what we'll consider normal in the future.
One last point, and one that speaks to the title of this post: If your body is not functioning in the way you believe it should, or in the way you want, you are experiencing a "disorder" of sorts. This becomes all the more cogent when there's a way to overcome the limitation, namely through some sort of medical intervention. The argument can be made that a condition becomes a condition once we have the means to overcome it.
So ladies, don't believe the negative hype. You know your own mind and body best, and if you believe that taking a pill can and will enhance your sex life, go for it.