Sleep Thresholds in Depression

There are conflicting psychiatric opinions about the value of separating depressive illnesses into several syndromes on clinical grounds, and so far experimental attempts to reach a classification of depression by distinguishing physiological or biochemical features which characterize one group rather than another have had only limited success. One interesting series of experiments in this area has been that of Shagass and his colleagues on the sedation threshold (Shagass et al. , 1956, Shagass and Naiman, 1956, Shagass, 1954); they report that neurotic and psychotic depressions can be differentiated by means of EEG and other reactions to sodium amytal (amylobarbitone sodium) neurotics requiring greater amounts of the drug to reach the sedation threshold.