The Olfactory Reference Syndrome is a psychiatric disorder, characterized mainly by the person who suffers from it being vehemently convinced that he or she gives off a bad body odor. But are there hallucinations in such a disorder, and delusions?

Throughout this article we will try to answer these questions. Furthermore, based on different studies, we will explain in detail what this disorder consists of, what some of the proposed etiological hypotheses are, its symptoms and, finally, the treatments used to combat it.

Olfactory reference syndrome

The Olfactory Reference Syndrome (ORS) consists of a hallucinatory psychiatric disorder . It is primarily characterized by a persistent preoccupation with smell, along with other symptoms such as shame and distress. On a social level, it is accompanied by avoidance behaviours and social isolation.

This syndrome is a variety of a delusional, somatic-type disorder. The individual with Reference Olfactory Syndrome strongly believes that he or she gives off a foul odor, and that others may notice the odor.

On a clinical level, it is therefore a delusion in addition to a hallucination (although there is controversy about the existence of these symptoms, as we shall see later). In the DSM-5 (Diagnostic Manual of Mental Disorders), it is proposed to classify ORS as a separate disorder.

Due to the characteristics of the syndrome, most patients with Reference Olfactory Syndrome do not consult psychiatrists or psychologists, but other types of professionals, such as: dermatologists, dentists, dermatologists or even surgeons, due to their “obsession” with the bad body odor they give off.


The prognosis of the olfactory reference syndrome had always been considered unfavorable; however, a 2012 review by the authors Begum and McKenna showed that two-thirds of patients (out of a sample of 84) improved partially or recovered completely.

Demographic data

The prevalence of ORS is higher among men than women. In particular, single men predominate. The age of onset ranges from late adolescence to early adulthood.


As for the origin of the olfactory reference syndrome, it was Pryse-Phillips who, in 1971, published a long list of cases. Philips separated the cases of ORS from cases with similar symptoms, belonging to schizophrenic, affective or organic type psychosis.


As for the cause of the Olfactory Reference Syndrome, it is actually unknown, as in many other psychiatric disorders. However, there are some etiological hypotheses, which refer to certain serotonergic and dopaminergic dysfunctions in the brain of people with ORS .

These dysfunctions are related to the repetitive cleaning and checking behaviors shown by these patients, similar to those shown by people with an Obsessive Compulsive Disorder (OCD).

Other causal hypotheses are in line with certain mismatches in some regulatory genes, such as Hoxb8 and SAPAP3 (related to the limbic lobe and basal ganglia).

On the other hand, there are also cases of people with Reference Olfactory Syndrome who have suffered some kind of brain injury, as well as temporal lobe epilepsy. However, these are all hypotheses with a neurobiological basis, and there are none that have been proven to be 100% causative of ORS.

Social and psychological factors

As for the more psychological and social causes, in half of the cases of ORS there is a precipitating event just before the onset of the symptoms of the disorder. Such events usually involve some form of denigrating admonition from others.

Stress may also be at the root of this disorder, as well as an obsessive, suspicious, and paranoid personality (and in extreme cases, an obsessive personality disorder or a paranoid personality disorder).


What symptoms accompany Olfactory Reference Syndrome? Let’s look at the 4 main symptoms, in addition to the suffering inherent in the disorder .

1. Concern about body odor

The main symptom of Referenced Olfactory Syndrome is a significant concern with body odor; that is, the person strongly believes that he or she is giving off a bad odor.

However, there is controversy as to whether such concern is delusional in all cases of the syndrome or not. It is also not clear whether there is always a hallucination associated with such concern or not.

Hallucination and/or delirium?

In relation to these controversies about the presence or absence of delirium and hallucination, a recent review (2012) by the authors Begum and McKenna, found that 22% of patients with Reference Olfactory Syndrome manifested an olfactory-type hallucination associated with concern about bad smell (vs. 75% of the original Pryse-Phillips list, who had such a hallucination).

As for the presence or not of delirium, this review shows that 52% of the patients had it; in the rest of the patients, however, the concern was based on an idea that oscillated between the overvalued idea and the obsessive idea.

2. Feelings of shame

Another symptom of ORS is an intense feeling of shame about others, so that the person suffers because he or she is convinced that he or she smells bad, and that others notice it. That is why they feel deeply ashamed, and have a hard time.

On the other hand, according to studies, more than 75% of patients with Reference Olfactory Syndrome interpret other people’s words and gestures in relation to themselves. In other words, patients believe that they speak badly of themselves and that they criticize them.

3. Constant check

People with ORS spend a lot of time checking their body odor, as they are “obsessed” with smelling more. They also engage in other compulsive behaviours in order to pretend to be in one place, or to disguise their own smell.

4. Social isolation

The above symptoms eventually cause the person to become socially isolated, which also results in social and occupational disability and great difficulty in leading a “normal” life.

In fact, of the original case list drawn up by Pryse-Phillips, only 3% of those affected by the olfactory reference syndrome were socially active.


As for the treatment of the Reference Olfactory Syndrome, we find, broadly speaking, two types of treatment: psychological and pharmacological.

On a psychological level, psychotherapy is used. Although it can be worked from different orientations, cognitive behavioural therapy is recommended, in order to eliminate the cognitive distortions associated with body odour, as well as checking and testing behaviours.

EMDR (Eye Movement Desensitization and Reprocessing) therapy has also been used. Specifically, a 2008 study by McGoldrick, Begum and Brown reveals the success of 5 patients through this therapy, which, however, is not useful in other psychotic conditions.

At the pharmacological level, antipsychotics and antidepressants are used s. For its part, a study reveals that 33% of the patients with Reference Olfactory Syndrome treated with antipsychotics had obtained very positive results; the same was true of 55% of the patients treated with antidepressants.

Bibliographic references:

  • Begum, M. and McKenna, P.J. (2011). Olfactory reference syndrome: a systematic review of the world literature. Psychol Med, 41:453-61.

  • Bizamcer AN, Dubin WR, Hayburn B. (2008). Olfactory reference syndrome. Psychosomatics, 49:77-81.

  • Cruzado, L., Cáceres-Taco, E. and Calizaya, J.R. (2012). About a case of olfactory reference syndrome. Clinical case. Psychiatry SP Proceedings, 40(4):234-8.

  • McGoldrick T, Begum M, Brown KW. (2008). EMDR and Olfactory Reference Syndrome. A case series. Journal of EMDR, 2:63-8.

  • Phillips KA, Gunderson C, Gruber U, Castle D. (2006). Delusions of body malodour; the olfactory reference syndrome. In: Brewer W, Castle D, Pantelis C, eds. New York: Cambridge University Press, 334-53.