A questionnaire, the Sensation-Seeking Scale (SSS), was administered to 70 normals and 70 randomly selected mental hospital patients. High scorers were classified as Sensation-Seeking and low scorers as Sensation-Avoiding. Sensation-Seeking was found more characteristic of normals, while Sensation-Avoiding typified mental patents as a group; females were less Sensation-Seeking than males; with increasing age all Ss tended to become more Sensation-Avoiding. A small group of patient and normal volunteers, representing extremes of scores on the S S S, were subsequently placed in sensory deprivation; differential responses seemed to relate to classification on the S S S rather than to diagnostic status. Sensation-Seeking Ss experienced discomfort, anxiety, boredom, and cognitive and perceptual disorganization (including hallucinations of a mild type), while Sensation-Avoiding Ss reported none, and also reported feeling better.