[Orientational study on the plasma tyrosine circadian rhythm in depressive syndromes of various etiology]

Manic-depressive states and daily temperature. Some circadian studies

Proceeding from the hypothesis of disturbed circadian rhythms in endogenous depression, we observed the oral temperature of four patients in a long-term study. The results showed the following: 1) Depression is linked to higher mean daily temperatures compared with normal states. In manic states, the mean daily temperature is even higher than in depressive states. Sleep deprivation as effective treatment causes a decrease in mean daily temperature. 2) The daily temperature maximum changes its position in depressive states. This is interpreted as indicating a disturbed circadian system. 3) A period shorter or longer than 24 h cannot be observed in depressive states.

The effect of sleep deprivation on depressed patients

In this paper an account is given of the effect of single-night sleep deprivation (SD) therapy in 124 depressive patients of different diagnostic groups. Phasic depressives showed a marked improvement after treatment by sleep deprivation. Because these improvements were often of short duration, we repeated the treatments and combined them with thymoleptic drugs. In the group of neurotic depressives the therapeutic effect of sleep deprivation varied; on the whole, however, the improvement was less marked. It is pointed out that the vital symptoms and "critical time" are of importance. Sleep deprivation can be explained as a resynchronization of disturbed circadian rhythms brought about by interrupting these rhythms.

The daily rhythm of plasma tryptophan and tyrosine in depression

The study dealt with the level of and diurnal alterations in the concentration of tryptophan, free tryptophan and tyrosine in the blood plasma of 20 inhibited depression patients and 10 healthy controls. The results suggested that there was no distinct relationship between either the total plasma tryptophan or plasma tyrosine level and depression. On the other hand, the free plasma tryptophan level was, at all the times of day at which measurements were made, either significantly or almost significantly higher in the patients than in the controls. It was further found that the results of measurement were related to the patients' clinical improvement, as measured by the Hamilton test, in such a way that after four weeks of treatment the free plasma tryptophan level in 'poorly improved' patients continued to be significantly higher in comparison with the controls, whereas the values for the 'well improved' patient group did not differ greatly from the corresponding values for the control group any longer. It may be hypothesized that the rise in the free plasma tryptophan in depressive patients might represent an effort made by the peripheral body to compensate for the slowed-up serotonin metabolism of the brain, whereby the tryptophan mobilized from the periphery would serve as a sort of 'endogenous antidepressant' provided by the organism itself.