(The full version of this wonderfully informative article by Linda F. Palmer can be found at: http://www.attachmentparenting.org/support/articles/artchemistry.php)
The Chemistry of Attachment (part 4)
Opioids & Rewards
Opioids (pleasure hormones) are natural morphine-like chemicals created in
our bodies. They reduce pain awareness and create feelings of elation. Social
contacts, particularly touch-especially between parent and child- induce opioid
release, creating good feelings that will enhance bonding. Odor, taste,
activity, and even place preferences can develop as the result of opioid release
during pleasant contacts, and eventually the sight of a loved one's face
stimulates surges. Opioid released in a child's brain as a conditioned response
to a parent's warm hugs and kisses can be effective for helping reduce the pain
from a tumble or a disappointment.
Parents "learn" to enjoy beneficial activities such as breastfeeding and
holding, and infants "learn" to enjoy contact such as being held, carried, and
rocked, all as a response to opioid release. Babies need milk, and opioids are
nature's reward to them for obtaining it, especially during the initial
attempts. The first few episodes of sucking organize nerve pathways in the
newborn's brain, conditioning her to continue this activity. This is the reason
that breastfed babies sometimes have trouble if they are given bottles in the
newborn nursery-early exposure to bottles creates a confusing association of
pleasure with both bottle nipples and the mother's breast. In fact, any
incidental sensations experienced during rocking, touching, and eating that
aren't noxious can become part of a child's attachment and will provide comfort.
It could be the warmth of mother's body, father's furry chest, grandma's gentle
lullaby, a blanket, or the wood-slatted side of a crib.
Prolonged elevation of prolactin in the attached parent stimulates the opioid
system, heightening the rewards for intimate, loving family relationships,
possibly above all else. Just as with codeine and morphine, tolerance to natural
opioids can occur, which will reduce the reward level for various activities
over time. But this is not a problem for attached infants and parents, because
higher levels of oxytocin, especially when created through frequent or prolonged
body contact, actually inhibit opioid tolerance 7, protecting the
rewards for maintaining close family relationships. On the other hand, consuming
artificial opioid drugs replaces the brain's need for maintaining family
contacts.
Once a strong opioid bonding has occurred, separation can become emotionally
upsetting, and in the infant possibly even physically uncomfortable when opioid
levels decrease in the brain, much like the withdrawal symptoms from cocaine or
heroin. When opioid levels become low, one might feel like going home to hold
the baby or like crying for a parent's warm embrace, depending on your point of
view. Sometimes alternate behaviors are helpful. For instance, thumb-sucking can
provide some relief from partial or total withdrawal from a human or rubber
nipple and can even provide opioid-produced reminiscences for a time.
