The Neural control of mood: The possible role of the adrenergic system in the medulla

Abstract

Mood in humans is a complex phenomenon that integrates emotion (e.g. happiness and sadness), cognition, perception, ideation, and action in a coherent manner. In bipolar disorder extremes of mood (up or down) occur outside the normal range, in which all the above functions are coherently affected. Mood is controlled by a series of separate but interactive brain circuits that involve much of the brain, but particularly the limbic system. The question addressed in this paper is whether the coordination of all these separate systems into one coherent functional mood is mediated by non-linear dynamics acting between these systems as equal participants; or whether it is affected by a single master regulator controlling the others. The possible roles, as master regulators, of non-linear dynamically linked populations of neurons, and of the C1–C3 adrenergic nuclei in the medulla is discussed.

Introduction

The well-known disorders of bipolar disorder (mania and depression) are described in textbooks of psychiatry by observers from the outside. But a much more graphic account from the inside is provided by Custance’s (1952) autobiographical account of his own illness that involved severe bouts of mania and depression with periods of normality in between. His intelligence and a gift of expression enable him to give a vivid picture of his experiences—of ecstasy beyond belief in mania—of suffering without parallel in depression—in a manner that dry clinical accounts in psychiatric textbooks, and statistically orientated clinical research, often fail to convey. In addition, there were changes in all aspects of his mental life besides emotions—perception, cognition, motivation, and action. Before the onset of his bipolar disorder in his early 30’s, he lived a perfectly ordinary life. His first bout of mania abruptly changed all that. When the bout subsided, he returned to his ordinary self, only to suffer several relapses, interspersed with equally serious episodes of depression. His report poses a stimulus to those who are looking for the neurobiological basis of the disease, and provides valuable data for this enterprise. Custance first describes what mania is like, and then gives his account of depression.