C D M H

 

Endocrinological Aspects of Behavioral
Dysregulation During Early Development

PI: Delia M. Vazquez, MD
Co-Investigators: Barbara Felt, MD
Susan McDonough, Ph.D.
Sheryl Olson, Ph.D.

ABSTRACT

In this study the interrelations of biological, psychological, and social functioning are examined in an effort to delineate neuroendocrine and physiological measures linked to characteristics of infants and children in multiple-risk environments that may predispose them to mental health problems. We focus on infants who have problems of physiological regulation, primarily, excessive crying, sleep disturbances and feeding problems currently being studied in the Michigan Family Study. We are studying the limbic-hypothalamic-pituitary-adrenal (LHPA) axis, one of the neuroendocrine systems that contributes to individual differences of physiological and behavioral regulation to arousal.

In this project we focus on two aspects of the LHPA axis that have had limited study in children: a) the development of an "adult like" cortisol circadian rhythm, and b) the stress response in infants with physiological regulation problems. Hormonal measurements are performed in saliva that are obtained both in the home and laboratory setting. We hypothesize that: 1) The establishment of predictable cortisol rhythm as is observed in adults is the antecedent to stable basal cortisol levels indicative of a "less reactive" LHPA axis; 2) Infants who do not regulate their behavior effectively have dysregulated circadian rhythmicity, increased activation of the cortisol response to stress and caretakers that interfere with the coping efforts of the child.

The results of this study will help us correlate physiological markers with individual adaptive/maladaptive behavioral coping strategies, in both children and their caretakers. The intent is to increase our understanding of developmental trajectories and neuroendocrine dysfunctions that may lead to mental health problems.