If it is neurotransmitters that determine, at least in part, whether or not we will be depressed, then what forces shape the production and transmission of these neurochemicals in the brain? It turns out that the mother-child relationship is critical to our developing brains. And it goes beyond that. Loneliness and social isolation contribute to depression. We may not need everybody but all of us need somebody. Animals, including us humans, seek out companionship. The need for it is programmed into our ancestral brains. The image to the left shows Suryia the orangutan and Roscoe, the Blue Tick Hound. While living at the Institute of Greatly Endangered and Rare Species in Myrtle Beach, South Carolina, Suryia one day came across the path of a down-and-out dog and they have since become best friends and constant companions
Stress and isolation are major causes of depression:
In "A Gene for Nothing," published in Discover, October, 1997, Robert Sapolsky writes: "Periods of psychological stress involving loss of control and predictability during childhood may well predispose one toward adult depression." He points out that the timing of losses is important. Given identical losses and stress, a child who experiences misfortune over a one-year period instead of over a six-year period is more likely to develop depression.
In the middle part of the last century, Harlow F. Harlow studied the effects of isolation on baby monkeys. To do this, he removed any semblance of a mother or other companion, and provided only nutritional sustenance. As Deborah Blum points out in Love at GOON Park, Harry Harlow and the Science of Affection (2002), the monkeys sunk into a despairing stupor similar to symptoms of severe depression in humans. After thirty days, on removal from isolation, the monkeys were so disturbed that, according to Blum's account, "two of them refused to eat and starved themselves to death." Blum interviewed professionals who worked with Harlow, now deceased, on the isolation experiments. After being isolated for six months, a horrific picture emerges, explains Blum including "animals stumbling blindly around their cages, rocking themselves, chewing their skin open."
Harlow is pictured at right (image links to source). Erin Schultheis, Muskingum University, compiled the webpage from which this picture is taken. Regarding depression, Blum quotes Harlow: "In other words, depression results from social separation when the subject loses something of significance, has nothing with which to replace that loss, and is incapable of altering this predicament by its own actions."
The late Saul Schanberg, a renowned nueroscientist and physician at Duke University, is recognized for his research "on the importance of touch in normal growth and development," states the 2009 Duke Medical Alumni News. Schanberg found that "specific types of touch led to better health and shorter hospital stays for premature infants." Schanberg's experiments emphasize the importance of attachment, especially involving contact comfort, in normal mammalian development. Blum writes: "Schanberg found that when mother rats licked their babies, the action produced a cascade of much needed compounds, in fact, the growth hormones that produce normal body development. Remove the mother—remove the touch of her tongue, and the baby rats became stunted beings."
Regarding attachment and subsequent mental health, Martin Teicher and his team at McLean Hospital, a psychiatric teaching affiliate of Harvard Medical School, have "been using brain imaging technologies to compare people from a safe and protective family and those who grew up in an abusive one," writes Blum in Love at GOON park. She quotes Teicher: "We know that any animal exposed to stress and neglect early in life develops a brain that is wired to experience fear, anxiety, and stress. We think the same is true of people." a link is provided here to a news article about the Teicher team's work titled "Cutting Words May Scar Young Brains."
The mother-child bond, contact comfort, and depression:
Monkeys from the Harlow laboratory are pictured at left and below. These images link to their source, Classics in the History of Psychology. Christopher D. Green, York University, Toronto, developed this internet resource.
Harlow describes his early work in "The Nature of Love" (1958), first published in American Psychologist. Harlow and his team separated macaque monkeys from their mothers shortly after birth and suckled them on tiny bottles in a laboratory setting. The monkeys displayed a "strong attachment to the cloth pads (folded gauze diapers) which were used to cover the hardware-cloth floors of their cages," writes Harlow. "The infants clung to these pads and engaged in violent temper tantrums when the pads were removed and replaced for sanitary reasons."
Later, experiments with surrogate mothers in the form of either a bare wire mother or a cloth-covered model further illustrated the infant monkeys' intense need for contact comfort. In "The Nature of Love," Harlow writes: "With age and opportunity to learn, subjects with the lactating wire mother showed decreasing responsiveness to her and increasing responsiveness to the nonlactating cloth mother." When Harlow removed mother surrogates from infant monkeys, the frustrated infants often engaged in abnormal behaviors including rocking, sucking, and frantic clutching of their bodies. This even for a mother made of wire and cloth.
The effects of isolation on parenting skills and propensity for child abuse:
Scientists in Harlow's laboratory studied the mothering skills of a few female monkeys that had been raised in isolation. The scientists used forced pregnancies, since these particular females had no social intelligence and were unreceptive to mating. Blum writes: "These monkey mothers that had never experienced love of any kind were devoid of love for infants, a lack of feeling unfortunately shared by all too many human counterparts. Most of the loveless mothers just ignored their infants. Unfortunately, not all did. One held her infant's face to the floor and chewed off his feet and fingers. Another took her baby's head in her mouth and crushed it. That was the end of the forced pregnancies."
Blum includes a statement Harlow made to This Week, March 3, 1961: "If monkeys have taught us anything it's that you've got to learn how to love before you learn how to live."
We will further discuss the parent-child relationship and what is called attachment theory, below. But first, we will take a look at hospitalism, which Wikipedia defines as a "pediatric diagnosis used in the 1930s to describe infants who wasted away while in hospital." In essence, during this era of medicine, well-meaning physicians isolated human infants with tragic results.
Hospitalism and the reign of the behaviorists:
John B. Watson, a godfather of American behaviorist psychology, is pictured at left testing the grasp reflex of a baby, circa 1916-20. The New York Times published this photograph, originally from the Johns Hopkins University archives.
In the first half of the twentieth century, prominent psychologists came to view competent mothering as simply the provision of shelter and sustenance combined with appropriate stimuli to condition desired behavior. Such resources and stimuli could be measured, thus convincing psychologists that their science was real. "Give me a dozen healthy infants … and my own specified world to bring them up in," said behaviorist John B. Watson, "and I'll guarantee to take any one at random and train him to become any type of specialist … regardless of his talents, penchants, tendencies, abilities, vocations, and the race of his ancestors."
"Behaviorists believed that behavior could be understood independently of the rest of biology, without attention to the genetic makeup of the animal or the evolutionary history of the species," asserts Steven Pinker in The Blank Slate: The Modern Denial of Human Nature (2002). Pinker writes: "As late as 1974, Skinner wrote that studying the brain was just another misguided quest to find the causes of behavior inside the organism rather than out in the world."
During the reign of the behaviorists, mothers who fussed over their babies were labeled neurotic. Variables in children's individual temperaments were not considered consequential. It wasn't the special quality of a mother's touch in changing a diaper that was deemed important. It was the diaper change that made the difference. Any competent caregiver would do. Meanwhile, germ theory increasingly defined the practice of medicine. In hospitals, sick infants and young children were placed in very sterile, isolated environments. Parents were not allowed daily visits. Doctors discouraged handling of the small patients in order to deter germ transmission. Regardless of the sterile conditions, however, many of the children succumbed to a disease state eventually referred to as "hospitalism" and died.
In Monkeyluv and Other Essays on Our Lives as Animals, (2005), Robert M. Sapolsky sums up the situation.
The infants in hospitals, despite adequate nutrition, a sufficient number of blankets, and various medical menaces kept at bay, wasted away from emotional deprivation. And as they became depressed and listless, their immune systems were likely to weaken (as has been shown for young nonhuman primates undergoing similar deprivation). Soon they'd be falling victim to the gastrointestinal or respiratory infections so common in hospitals at the time, at which point, the feverish medical enthusiasm for aseptic isolation would kick in. The pediatricians would see the infections as a cause, rather than an effect of hospitalism, and the kids would quickly be consigned to isolated cubicles where the goal would be their never being touched by human hands. And the mortality rate would soar.
To continue exploring CorticalBrain.com in an orderly fashion, link to Subcortical Brain Structures, Stress, Emotions, and Mental Illness. Or, you may Explore the Site Outline.
If you would like be informed about new features and improvements as they are added to CorticalBrain.com, please send an e-mail to info(at)corticalbrain.com