We can learn to read symptoms not only as problems to be overcome but as messages to be heeded. (p268) - Gabor Maté

Environmental influences also affect dopamine. From animal studies, we know that social stimulation is necessary for the growth of the nerve endings that release dopamine and for the growth of receptors that dopamine needs to bind to in order to do its work. In four-month-old monkeys, major alterations of dopamine and other neurotransmitter systems were found after only six days of separation from their mothers.

“In these experiments,” writes Steven Dubovsky, Professor of Psychiatry and Medicine at the University of Colorado, “loss of an important attachment appears to lead to less of an important neurotransmitter in the brain. Once these circuits stop functioning normally, it becomes more and more difficult to activate the mind.”

A neuroscientific study published in 1998 showed that adult rats whose mothers had given them more licking, grooming and other physical-emotional contact during infancy had more efficient brain circuitry for reducing anxiety, as well as more receptors on nerve cells for the brain’s own natural tranquilizing chemicals. In other words, early interactions with the mother shaped the adult rat’s neurophysiological capacity to respond to stress.

In another study, newborn animals reared in isolation had reduced dopamine activity in their prefrontal cortex — but not in other areas of the brain. That is, emotional stress particularly affects the chemistry of the prefrontal cortex, the center for selective attention, motivation and self-regulation. Given the relative complexity of human emotional interactions, the influence of the infant-parent relationship on human neurochemistry is bound to be even stronger.

In the human infant, the growth of dopamine-rich nerve terminals and the development of dopamine receptors is stimulated by chemicals released in the brain during the experience of joy, the ecstatic joy that comes from the perfectly attuned mother-child mutual gaze interaction. Happy interactions between mother and infant generate motivati

There are two possibilities why your memories of childhood are so hazy,” I suggest to people. “Either nothing happened worth remembering, or too much happened that may be hurtful for you to recall.” As we shall see in a later chapter, human beings can tune out entire periods of their lives that were characterized by emotional pain.

Much of what we call personality is not a fixed set of traits, only coping mechanisms a person acquired in childhood. (p127)