Studies of endocrine activity, plasma tryptophan and catecholamine excretion on psychosurgical patients

Abstract

The Geoffrey Knight Psychosurgical Unit admits patients on a regular basis and thus offers special opportunities for studying severely ill psychiatric cases, all having one particular treatment under relatively controlled conditions. The opportunity has been taken to repeat various metabolic studies previously reported to be abnormal in some psychiatric illnesses. In the present investigation several measures of endocrinological activity were studied, as was plasma tryptophan, both free and bound. None of these data confirmed reports of abnormalities and neither did the values found at operation help to predict clinical outcome 1 year later, which was another possibility. Urinary catecholamines were also measured and 2 weeks after operation. Male patients, regardless of diagnosis, showed a mean increase in adrenaline output after operation compared with the pre-operative value and this was significantly different from the females, who showed a small mean decrease. The depressed patients showed a significant reduction in noradrenaline excretion after operation compared with before operation and this trend was enhanced in those of good outcome at 1 year, the difference from those who responded poorly being significant. It could be that the ventromedial lesion that is produced alters noradrenaline metabolism or autonomic activity in depression and this possibility merits further study.

Plasma Tryptophan and Five Other Amino Acids in Depressed and Normal Subjects

“…We reviewed 13 such studies conducted since 1973. In six of the 13,11 18 there were no differences in plasma TRP levels between depressed and normal control subjects. In four studies,1"2-free TRP concentration was lower in depressed patients, and in one study211 it was higher.…”

During the Long Way to Mars: Effects of 520 Days of Confinement (Mars500) on the Assessment of Affective Stimuli and Stage Alteration in Mood and Plasma Hormone Levels

“…Previous studies have found evidence of decrement in the variables of cognitive performance [13], [14], [15], team cohesion [1], [3], [4], [16], locomotor function [10], [11], [17], circadian rhythm and sleep [2], [3], [18], [19], etc. Moreover, the strong association between the function of the neuroendocrine system and emotion processing and stress coping has also been observed [20], [21], [22], [23]. To the best of our knowledge, however, the effect of long-term confinement on the assessment of affective stimuli has not yet been reported.…”

Effect of stress on prefrontal cortex function

“…However, though the effect of stress on the turnover of monoamine neurotransmitters was studied almost as soon as analytical methods made it possible to measure brain levels of these compounds (Sepping et al, 1977;Axelrod and Reisine, 1984), few studies have examined the effect of stress on glutamate levels. This is in part due to the fact that until the early 1980s, glutamate was not recognized as a neurotransmitter.…”