It is chronic, lasting many years or even decades with worsening of symptoms rather than spontaneous remission. Transformation to another psychiatric condition is unlikely, although very rarely what appears to be ORS may later manifest into schizophrenia, psychosis, mania, or major depressive disorder. The most significant risk is suicide. When treated, the prognosis is better. In one review, the proportion of treated ORS cases which reported various outcomes were assessed. On average, the patients were followed for 21 months (range: two weeks to ten years). With treatment, 30% recovered (i.e. no longer experienced ORS odor beliefs and thoughts of reference), 37% improved and in 33% there was a deterioration in the condition (including suicide) or no change from the pre-treatment status. Epidemiology
Cases have been reported from many different countries around the world. It is difficult to estimate the prevalence of ORS in the general population because data are limited and unreliable, and due to the delusional nature of the condition and the characteristic secrecy and shame.For unknown reasons, males appear to be affected twice as commonly as females. High proportions of ORS patients are unemployed, single, and not socially active. The average age reported is around 20–21 years, with almost 60% of cases occurring in subjects under 20 in one report, although another review reported an older average age for both males (29) and females (40). History
The term olfactory reference syndrome was first proposed in 1971 by William Pryse-Phillips.
The variants of taijin kyōfushō (shubo-kyofu "the phobia of a deformed body" and jikoshu-kyofu "fear of foul body odor") are listed under 300.3 (F42) "other specified obsessive compulsive and related disorders", and is about someones fear that his or her body, or its functions, is offensive to other people. There are four subtypes of taijin kyōfushō. 17% of these individuals have "the phobia of having foul body odor", the subtype termed jikoshu-kyofu. Although taijin kyōfushō has been described as a culture-bound syndrome confined to east Asia (e.g. Japan and Korea), it has been suggested that the jikoshu-kyofu variant of taijin kyōfushō is closely related or identical to ORS, and that such a condition occurs in other cultures. However, some Western sources state that jikoshu-kyofu and ORS are distinguishable because of cultural differences, i.e. Western culture being primarily concerned with individual needs, and Japanese culture primarily with the needs of the many. Hence, it is claimed that ORS mainly focuses on the affected individuals embarrassment, and jikoshu-kyofu is focused on the fear of creating embarrassment in others. In this article, jikoshu-kyofu and ORS are considered as one condition. Synonyms for ORS, many historical, include bromidrosiphobia, olfactory phobic syndrome, chronic olfactory paranoid syndrome, autodysomophobia, delusions of bromosis, hallucinations of smell and olfactory delusional syndrome. By definition, the many terms which have been suggested in the dental literature to refer to subjective halitosis complaints (i.e. when a person complains of halitosis yet no odor is detectable clinically) can also be considered under the umbrella of ORS.