" Children who don’t feel safe in infancy have trouble regulating their moods and emotional responses as they grow older. By kindergarten, many disorganized infants are either aggressive or spaced out and disengaged, and they go on to develop a range of psychiatric problems.23 They also show more physiological stress, as expressed in heart rate, heart rate variability,24 stress hormone responses, and lowered immune factors.25 Does this kind of biological dysregulation automatically reset to normal as a child matures or is moved to a safe environment? So far as we know, it does not. Parental abuse is not the only cause of disorganized attachment: Parents who are preoccupied with their own trauma, such as domestic abuse or rape or the recent death of a parent or sibling, may also be too emotionally unstable and inconsistent to offer much comfort and protection. "
― Bessel van der Kolk , The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma