Biological Stress Systems and Brain Development in Maltreated Children With PTSD
Michael D. De Bellis, MD, Western Psych. Institute & Clinic
April 1, 1999
Child maltreatment is increasing in the United States and may be the most common cause of interpersonal traumas and posttraumatic stress disorder in children and adolescents (De Bellis 1997). Developmental Traumatology, the systematic investigation of the psychiatric and psychobiological impact of overwhelming and chronic interpersonal violence on the developing child, is a relatively new area of study. It synthesizes knowledge from an array of scientific fields, including developmental psychopathology, developmental neuroscience, and stress and trauma research. One active area of research involves the effects of maltreatment and related stressors on major body stress response systems such as the hypothalamic-pituitary-adrenal axis, the catecholamine system the locus ceruleus-norepinephrine/sympathetic nervous system, and the immune system (De Bellis and Putnam 1994).
Recent research at Western Psychiatric Institute and ClinicUs Developmental Traumatology Laboratory suggests that the overwhelming stress of childhood maltreatment is associated with alterations of biological stress systems and with adverse influences on brain development (De Bellis et al 1999a; De Bellis et al 1999b). In one study, 18 prepubertal maltreated children with PTSD, nontraumatized children with DSM-III-R overanxious disorder (N=10), and healthy controls (N=24) underwent 24 hour urine collection for measurements of urinary free cortisol, a reflection of HPA axis regulation, and urinary catecholamine excretion. Maltreated subjects with PTSD excreted significantly greater amounts of UFC and catecholamines than nonabused controls. These biological stress measures correlated positively with duration of the PTSD trauma and symptoms of intrusive thoughts, avoidance, and hyperarousal (De Bellis et al 1999a).
In a second study, 43 maltreated children and adolescents with PTSD and 61 matched controls underwent comprehensive clinical assessments and an anatomical magnetic resonance imaging brain scan. Maltreated subjects with PTSD had 7.0 % smaller intracranial and 8.0% smaller cerebral volumes than matched controls.
The total midsagittal area of corpus callosum, the major interconnection between the two hemispheres that is broadly conceptualized as facilitating intercortical communication, and the middle and posterior regions of the corpus callosum, were smaller in abused subjects.
In contrast, right, left, and total lateral ventricles were proportionally larger than controls, after adjustment for intracranial volume. Intracranial volume robustly correlated positively with age of onset of PTSD trauma (i.e., smaller brains were associated with earlier onset of trauma) and negatively with duration of abuse.
Symptoms of intrusive thoughts, avoidance, hyperarousal and dissociation correlated positively with ventricular volume, and negatively with intracranial volume and total corpus callosum and regional measures. The decreased hippocampal volume reported in adults with PTSD was not found in the subjects (De Bellis et al 1999b).
These data suggest that chronically maltreated children with a diagnosis of PTSD manifest alterations of major biological stress systems including adverse influences on brain development. Although based on a cross-sectional analysis, thus causation can not be proven, these findings are intriguing and may have important social policy and treatment implications. Elucidating the biological sequelae and mechanisms of symptom production in PTSD and associated comorbid psychiatric disorders will pave the way to better clinical and social treatment of abused children. Accordingly, prospective longitudinal studies in developmental traumatology are critical to the effort to develop early interventions to attenuate the psychobiological dysregulation and adverse effects on brain development associated with maltreatment.
References
De Bellis, M.D. (1997). Posttraumatic stress disorder and acute stress disorder. In Ammerman RT, Hersen M (eds.), Handbook of Prevention and Treatment with Children and Adolescents. New York: John Wiley & Sons Inc., 455494.
De Bellis, M.D., Baum, A., Birmaher, B., et al. (1999a). A. E. Bennett Research Award. Developmental Traumatology: Part I: Biological Stress Systems. Biological Psychiatry, in press.
De Bellis, M.D., Keshavan, M., Clark, D.B., et al. (1999b). A.E. Bennett Research Award. Developmental Traumatology, Part II: Brain Development. Biological Psychiatry, in press.
De Bellis, M.D., Putnam, F. W. (1994). The Psychobiology of Childhood Maltreatment. In Child and Adolescent Psychiatric Clinics of North America 3:663677.
This work was supported primarily by the 1995 NARSAD Young Investigators Award, "Attention and Concentration in Maltreated Children with Posttraumatic Stress Disorder" and by NIMH Grant
No. 5 K08 MHO132402.