Environmental motion can induce physiological stress and trigger
motion sickness. In these situations, lower-than-normal levels of
adrenocorticotropic hormone (
ACTH) have been linked with increased susceptibility to
motion sickness in healthy individuals. However, whether patients with
primary adrenal insufficiency, who typically have altered
ACTH levels compared to the normal population, exhibit alterations in sickness susceptibility remains unknown. To address this, we recruited 78 patients with
primary adrenal insufficiency and compared changes in the
motion sickness susceptibility scores from 10 years prior to diagnosis (i.e. retrospective sickness rating) with the current sickness measures (post-diagnosis), using the validated
motion sickness susceptibility questionnaire (MSSQ). Group analysis revealed that
motion sickness susceptibility pre-diagnosis did not differ between controls and patients. We observed that following treatment, current measures of
motion sickness were significantly increased in patients and subsequent analysis revealed that this increase was primarily in female patients with
primary adrenal insufficiency. These observations corroborate the role of stress
hormones in modulating sickness susceptibility and support the notion of a sexually dimorphic adrenal cortex as we only observed selective enhancement in females. A potential mechanism to account for our novel observation remains obscure, but we speculate that it may reflect a complex sex-disease-drug interaction.