THE INFLUENCE OF A PLACEBO, BODY POSITION AND MEDICATION ON MOTION SICKNESS

Abstract

Studies were made of some of the factors that affect, or were believed to affect, the incidence of seasickness in large unselected groups. Sixty expts. involving over 15,000 unselected [male] subjects were carried out during landing craft training operations. LCVP''s were the barges used in all studies. There is no "placebo" effect. The incidence as well as the severity of sickness which develops in groups receiving a placebo and in untreated control groups is of the same order. This indicates that psychic factors are of minor importance in the causation of motion sickness. In landing craft the position of the body and/or the head is a potent factor in determining the incidence and severity of seasickness. The incidence is 3 to 5 times greater in crouching men as compared with standing men. 0.6 mg. of hyoscine alone, or in combination with hyoscyamine, atropine or certain barbiturates, is a very effective medication for the prevention of seasickness. The avg. protection found was 60%. Barbiturates alone are effective in preventing seasickness only under conditions where the incidence if untreated would be low or moderate. Where the sickness rate would be high (above 30%) the protective value of barbiturates as such falls off. Prostigmin prepns. are without any demonstrable prophylactic effect.