Solvent contamination from volatile components of a fiberglass glove box.

muscle twitches and the increase in the frequency and amplitude of individual eye movements. While exhaustive observations of these phenomena were not made in this study, it was evident that the intensification of twitching and ocular motility seen in the controls was not present in the convulsed cats. On the other hand, the EOG components of the recordings on the 1st recovery day from the convulsed cats were early identical with those obtained during base-line periods. The data indicate that the development of the REM deprivation-compensation effect is retarded by the occurrence of convulsions during the deprivation period. In this study, our attention was focused on the comparative evaluation of compensatory changes in REM sleep, although neurophysiological and behavioral changes in the waking state also have been observed (6). However, such changes usually require much longer periods of REM deprivation than were used in this series of experiments. In the absence of evidence to the contrary, it seems reasonable to assume that behavioral changes would also be retarded or reversed by ECS. We can offer one incidental observation in support of this contention: hypersexual behavior, appearing on the 21st day of REM-sleep deprivation in a male cat, disappeared after several electrically induced convulsions, although the REM-sleep deprivation had not been terminated. In view of the fact that one ECS per-day in nondeprived cats only accomplished a 30to 40-percent reduction in daily REM time (3), the effect of four convulsions in the present series was disproportionately large. The seizures may have been intensified by the prior deprivation. No attempt to quantify the response to ECS was made in this study, but more recently we have observed a marked prolongation of the tonic phase in mice during periods of REM-sleep deprivation (7). Our results suggest a means by which electroconvulsive shock therapy may be effective in depressive psychosis. It is a clinical commonplace that severe depressions are often accompanied by profound sleep disturbances. REM-sleep deprivation appears to be an inevitable consequence of any overall loss of sleep (8). If the various manifestations of the REM-deprivation effect (6, 9) contribute to the psychotic process, then it is not unreasonable that an alleviation of this effect by electroconvulsive shock therapy may be a critical factor in the successful course of treatment (10). HARRY B. COHEN RIcHARD F. DUNCAN II WILLIAM C. DEMENT Department of Psychiatry, Stanford University School of Medicine, Palo Alto, California, and Veterans Administration Hospital, Menlo Park, California