Motion sickness--key to neurobiologic variation.

Individual variation in motion sickness susceptibility correlates with a wide variety of perceptual, cognitive, and personality variables suggesting that it may be a unique index of individual difference in fundamental mechanisms of the orientation process. Data from a large ongoing clinical study involving over 1,500 psychiatric inpatients indicate a clear-cut association between a number of the MMPI scales (including Social Isolation, Ego Strength and Schizophrenia) and motion sickness susceptibility. Marked difference across the motion sickness susceptibility spectrum in the condition on discharge of lithium and antidepressant treated patients was also found, when compared to other drug therapies, suggesting specific drug responses by the motion sick group.