[Olfactory hallucinations in depression]

Olfactory hallucinations are rarely mentioned as a symptom of depressive disorder. This paper presents a review of the literature including a conceptual clarification and epidemiological aspects with an emphasis on the significance of olfactory hallucinations for psychopathology, in particular with respect to sensory perception and body self-awareness. The close relation to the olfactory reference syndrome is pointed at. Olfactory hallucinations are considered important for the biological interpretation of affective disorders. In this regard disturbed olfactory perception can be understood as an example of disturbed brain function in the state of depression. Olfactory symptoms are shown to be elements connecting primary affective disorders with other neuropsychiatric diseases as well as with neuroanatomical and neurophysiological models. A primary role is accordingly attributed to the temporal lobe epilepsies in which olfactory hallucinations as well as affective disturbances occur. The need for further investigation in this field is pointed out.