[Circadian rhythm-related EEG changes in endogenous depressions and manias]

From 10 endogenous depressive and 10 manic alert but relaxed patients closed-eye-EEG's were registered at 8.00 a.m., 12.00 noon, 4.00 p.m., and 8.00 p.m., and recorded on tape for computer processing. Simultaneously each time the body temperature was measured. The findings were compared with corresponding former data of 12 healthy young people and 10 healthy aged volunteers.

The peak-frequency of the manic patients proved to be significantly higher than that of the depressive ones, and besides slightly exceeded that of the healthy persons. While in the latter temperature and occipital peak-frequency ascend step by step from the morning to the evening, the depressive patients show a resembling increase only in outlines in the peak-frequency, whereas the temperature already decreases from 4.00 p.m. to 8.00 p.m. In the manic patients peak-frequency and temperature and delta-Power reach their acme at 4.00 p.m., but as well the peak-power as the power of alpha- and beta-frequency-bands show a trough just at 4.00 p.m. In the depressive patients, on the other hand, alpha-, theta, and delta-frequency-bands mainly have their summits at 12.00 noon. Finely the manic patients stand out by most significant band-power-variations between the distinct daytimes, while uninterrupted gradual increasing is extreme rare. In the depressive persons both these events scarcely are found. The healthy volunteers have intermediate positions. All in all the results show, that in endogenous depression circadian variations of EEG-parameters appear disorganized, while in mania a modified organization prevails.