Chronic stress in early childhood leads to depression, mental retardation

• High stress levels during infancy and early childhood can lead to the poor development of communication zones in brain cells -- a condition found in mental disorders such as autism, depression and mental retardation.
• These are the findings of Dr. Tallie Z. Baram and her collaborators at the UC Irvine College of Medicine, Neurocrine Biosciences, Inc., and the Max Planck Institute of Psychiatry.
• For the first time, the researchers have identified how increased amounts of a key messenger for stress, the neuropeptide CRH, can inhibit the normal growth of dendrites, which are branch-like protrusions of neurons that send and receive messages from other brain cells.
• "These findings may prove to be highly relevant for understanding the origins of several human brain disorders, and they also point to some potential preventive treatments," said Baram, the Danette Shepard Chair in Neurological Studies.
• In several human brain disorders where learning and similar thought processes are abnormal, dendrites in the hippocampus -- where learning and memory occurs -- have been found to be small or poorly developed.