Transdiagnostic Approach to Olfactory Reference Syndrome: Neurobiological Considerations

Olfactory reference syndrome (ORS) describes a constellation of emotional and behavioral symptoms that cause clinically significant distress or impairment arising from the false belief that one is emitting an offensive odor. Despite cases of ORS reported throughout the world over the last century, our knowledge and understanding of ORS remain relatively poor because of the limited literature-mostly case studies and series, but no clinical trials. ORS continues to pose significant diagnostic challenges within our current frameworks of categorizing mental disorders, including the Diagnostic and Statistical Manual of Mental Disorders and International Classification of Diseases. We review the ORS literature and discuss diagnostic parallels and challenges of placing ORS within specific categories. We also review the current research on the neurocircuitry of olfaction and of disorders with potential clinical relevance to patients presenting with ORS. While no primary neuroscientific research has specifically investigated ORS, an overlapping circuitry has been implicated in the neurobiology of obsessive-compulsive, trauma and stressor, and psychotic spectrum disorders, suggesting that the phenomenology of ORS can best be understood through a dimensional, rather than categorical, approach.