Olfactory hallucinations in a population-based sample

Eike Wehling; Josef J Bless; Marco Hirnstein; Bodil Kråkvik; Einar Vedul-Kjelsås; Kenneth Hugdahl; Anne Martha Kalhovde; Frank Larøi

doi:10.1016/j.psychres.2021.114117

Olfactory hallucinations in a population-based sample

Psychiatry Res. 2021 Oct:304:114117. doi: 10.1016/j.psychres.2021.114117. Epub 2021 Aug 8.

Authors

Eike Wehling¹, Josef J Bless², Marco Hirnstein², Bodil Kråkvik³, Einar Vedul-Kjelsås⁴, Kenneth Hugdahl⁵, Anne Martha Kalhovde⁶, Frank Larøi⁷

Affiliations

¹ Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway; Department of Physical Medicine and Rehabilitation, Haukeland University Hospital Bergen, Bergen, Norway. Electronic address: eike.wehling@uib.no.
² Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.
³ Nidaros District Psychiatric Center, Department of Research and Development, St. Olavs University Hospital, Trondheim, Norway; Department of Psychology, Norwegian University of Science and Technology, Trondheim, Norway.
⁴ Department of Research and Development, Division of Psychiatry, St. Olavs University Hospital, Trondheim, Norway; Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
⁵ Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway; Division of Psychiatry, Haukeland University Hospital, Bergen, Norway; NORMENT Center of Excellence, University of Bergen, Bergen, Norway; KG Jebsen Center of Neuropsychiatric Disorders, University of Bergen, Bergen, Norway.
⁶ Jaeren Distric Psychiatric Center, Bryne, Norway.
⁷ Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway; NORMENT Center of Excellence, University of Bergen, Bergen, Norway; Psychology and Neuroscience of Cognition Research Unit, University of Liège, Liège, Belgium.

PMID: 34391204
DOI: 10.1016/j.psychres.2021.114117

Abstract

Olfactory hallucinations referring to olfactory perceptions in the absence of chemical stimuli, occur in non-clinical and clinical populations. Few studies have investigated their prevalence in the general population and little is known about factors triggering and maintaining them such as substance use, severe life events, and mood. We analyzed self-report data from 2500 community dwelling Norwegians, aged 18-96 years, for occurrence of olfactory hallucinations and co-occurring hallucinations in other modalities (auditory, visual, tactile). Analyses included age, sex, self-reported symptoms of depression and anxiety, mental health status, and experience of severe life-events. The results show that 4.2% (95% CI 3.5-5.1%) reported having experienced olfactory hallucinations, and 56% of individuals experiencing olfactory hallucinations also reported these in combination with hallucinations in other modalities. Prevalence varied significantly in terms of age and sex, in that olfactory hallucinations were most frequently reported by young individuals and females. Self-reported symptoms of anxiety and experience of stressful life events were significantly associated with olfactory hallucinations, suggesting that experiencing olfactory hallucinations may negatively affect functioning and may increase the likelihood of developing psychopathology. Findings underline the need to continue to examine olfactory hallucinations albeit with a more comprehensive assessment in order to increase knowledge on this experience.

Keywords: hallucinations, sensory perception, phantosmia, population based; multimodal hallucinations.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anxiety Disorders
Female
Hallucinations* / epidemiology
Humans
Norway
Olfactory Perception*
Touch