Summary and Conclusions A survey of the sleep pattern change of 87 women patients admitted to an acute psychiatric ward of the Ontario Hospital, Toronto was reported. An alteration of sleep pattern is common to all psychiatric diagnostic categories and the specific symptoms of Evening Insomnia, Morning Insomnia, Frequent Wakening, Light Sleep, Sleep during the Day and Shortening of the total Sleep time is common to all of them. Evening insomnia, light sleep and shortness of sleep are related to the estimated severity of depression while evening insomnia alone was related to the estimated anxiety level. A total increase in sleep symptoms is related significantly to both the estimated depth of depression and the estimated height of anxiety. Shortening of the sleep time and evening insomnia are significantly increased in suicidal patients although changes in the quantity of dreams and increases of nightmares was not. The total sleep symptom score failed to achieve a level of significance. A change in the quantity of dreaming was related to the diagnosis of depression, especially psychotic depression, but not to depression depth, anxiety level, suicidal tendencies or age. Nightmares increased with a diagnosis of psychotic or neurotic depression, with the estimated level of depression but not with the estimated anxiety level or suicidal tendency. Nightmares significantly decrease with age. The factors of anxiety and depressive affect, suicidal tendencies and other like parameters may promise a more significant relationship to sleep disorder than the diagnostic category. The recall of dreams appears to be of more importance for the diagnostic categorization of depressive states than other sleep symptoms.

A review of some of the important recent findings on sleep and its disorders has been presented and they provide some insight into the mysterious process of sleep. Sleep is shown to be a very complex process which will require not only extension of the current researches but a revised approach into the areas covered by previous studies. Sleep is a unique state quite different from other phenomena of loss or change of consciousness. It is distinguished from hypnosis which may involve more the specific arousal system of the thalamus. Hypnotic blindness for example does not involve sleep changes but rather a reversal of the electrical activity of the visual cortex (38). Although there appears to be a system which alerts the sleeping organism to meaningful stimuli it seems that there is little evidence of significant new learning during sleep (12, 120, 153). Rather sleep involves the focusing of the activity of the central nervous system on its internal processes. Sleep produces a state of relative bodily inactivity but the central nervous system remains actively engaged in a restorative process not yet understood. The discovery of the REM state has shown the complexity of sleep. No study of the effect of physical or chemical stimuli on the nervous system during sleep will be adequate without the examination of effects and responses in the different phases of sleep. The lack of success of continuous sleep therapy may be in part due to suppression of REM sleep by the sedatives used (23). It should be stated, however, that clinical studies are also needed to supplement the more sophisticated and expensive scientific procedures. There are still many areas of controversy on the phenomenology of sleep disorder which need investigation.