There is significant debate over whether or not asexuality is a sexual orientation. It has been compared and equated with hypoactive sexual desire disorder (HSDD), in that both imply a general lack of sexual attraction to anyone; HSDD has been used to medicalize asexuality, but asexuality is generally not considered a disorder or a sexual dysfunction (such as anorgasmia, anhedonia, etc.), because it does not necessarily define someone as having a medical problem or problems relating to others socially. Unlike people with HSDD, asexual people normally do not experience "marked distress" and "interpersonal difficulty" concerning feelings about their sexuality, or generally a lack of sexual arousal; asexuality is considered the lack or absence of sexual attraction as a life-enduring characteristic. One study found that, compared to HSDD subjects, asexuals reported lower levels of sexual desire, sexual experience, sex-related distress and depressive symptoms. Researchers Richards and Barker report that asexuals do not have disproportionate rates of alexithymia, depression, or personality disorders. Some people, however, may identify as asexual even if their non-sexual state is explained by one or more of the aforementioned disorders.