The role of biological rhythms and blood glucose levels in maintaining a positive mood state.

Abstract

Although the effects of both the menstrual and circadian cycles on mood have been well documented, the question of whether the two interact to influence mood has not yet been addressed, despite evidence for such an interaction on other variables. Blood sugar level is a major contributor to the mediation of mood and is easily regulated by dietary intervention; there is also evidence that it is influenced by both the menstrual and circadian cycles. The present research takes a positive psychological approach to managing mood; the aims were to identify where natural variations in mood occur in relation to its underlying physiology, taking an applied approach to suggest ways of effectively managing positive mood and maintaining psychological well-being. A series of studies was carried out to measure fluctuations in mood in relation to biological rhythms, and in response to cognitively demanding situations and simple interventions. Mood was measured throughout the research using the UWIST Mood Adjective Checklist. The most consistent results were in relation to the Energetic Arousal dimension. This was shown to be influenced by both the menstrual cycle and the time of day, as well as an interaction between these two factors, and was consistently related to changes in blood glucose levels. Energetic Arousal also appeared to be more sensitive to the effectsof the suggested interventions. Diurnal changes in mood throughout the course of a normal day were more evident among women in their premenstrual to menstrual phases, and also become more apparent in response to cognitive tasks. Trait Anxiety was a mediating factor in how individuals reacted to such tasks. Mood was closely related to blood glucose levels, and raising blood glucose to a robust but safe level effectivelyenhanced positive mood in cognitively demanding situations. Oral contraceptives generally tended to eliminate menstrual cycle-related effects on mood and responses to intervention. It was concluded that mood states among healthy women are influenced by a complex interplay between biological rhythms, physiological states, individual differences and the context in which these moods take place. Simple interventions that can easily be incorporated into one’s daily routine may be efficacious in maintaining a positive mood state, which has beneficial implications for psychological well-being.