New research on asexuality shows why it’s so important for doctors and therapists to distinguish between episodes of low libido and a consistent lack of sexual attraction
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Over the past two decades psychological studies have shown that asexuality should be classified not as a disorder but as a stable sexual orientation akin to homosexuality or heterosexuality. Both cultural awareness and clinical medicine have been slow to catch on. It's only recently that academic researchers have begun to look at asexuality not as an indicator of health problems but as a legitimate, underexplored way of being human.
In biology, the word “asexual” typically gets used in reference to species that reproduce without sex, such as bacteria and aphids. But in some species that do require mating to have offspring, such as sheep and rodents, scientists have observed individuals that don't appear driven to engage in the act.
One of the main criteria of a "disorder", as per psychiatrists making a diagnosis via the DSM, is that it causes significant disruption in one's life, and distress or dysfunction. Asexual and demi people can be perfectly happy being the way they are and experience no distress about a lack of attraction beyond feeling confused or different. In contrast, I doubt many people with OCD are happy being stuck turning a light switch on and off for an hour because their brain tells them they aren't doing it the "right" way.