Fibrinolytic therapy and deep venous thrombosis.

SIR,-Further to the interesting leading article "Nutrition and Sleep" (20 May, p. 418) one may ask whether sleep is not the "natural" state and wakefulness merely a res,pite for the satisfaction of instinctual (and socially inculcated) drives. The hibernating animal is unlikely to chance upon dangerous predators. On this model the satisfqction of drives would lead to sleep and their continued frustration to insomnia. This would fit the observation that rats became totally insomniac if kept without food' and the sooorific value of the male orgasm.2 It has been observed that electrical stimulation in the regions of the tegmentum, posterior hypothalamus, and septal nuclei provide an extraordinarily powerful reward.3" Quoting these observations in a broadcast talk on drug addiction, Professor W. D. M. Paton has suggested that all drives may emanate from a single area in the brain and that the powerful appeal of narcotics arises from the simultaneous satiation of all drives by its effect on this area. It is noteworthy in this connexion that narcotic addicts go "on the nod" after intravenous administration. It may be relevant to point out that sedative drugs used for alleviating agitation and anxiety reduce activity5 and cause drowsiness. Could the restless anxious state be a manifestation of frustrated social drives?-I am, etc., MALCOLM WELLER