ORS may be misdiagnosed as schizophrenia. About 13% of schizophrenics have olfactory hallucinations. Generally, schizophrenic hallucinations are perceived as having an imposed, external origin, while in ORS they are recognized as originating from the individual. The suggested diagnostic criteria mean that the possibility of ORS is negated by a diagnosis of schizophrenia in which persistent delusions of an offensive body odor and olfactory hallucinations are contributing features for criterion A. However, some reported ORS cases were presented as co-morbid. Indeed, some have suggested that ORS may in time transform into schizophrenia, but others state there is little evidence for this. Persons with ORS have none of the other criteria to qualify for a diagnosis of schizophrenia.