← In the Realm of Hungry Ghosts Close Encounters with Addiction
In the Realm of Hungry Ghosts Close Encounters with Addiction Chapter 14. Through a Needle, a Warm, Soft Hug
Author: Gabor Mate Publisher: Berkeley, CA: North Atlantic Books Publish Date: 2010-1-5 Review Date: Status:📚
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Amazon Indians chewed coca long before the Conquest as an antidote to fatigue and to reduce the need to eat on long, arduous mountain journeys. Coca was also venerated in spiritual practices: Native people called it the Divine Plant of the Incas. In what was probably the first ideological “War on Drugs” in the New World, the Spanish invaders denounced coca’s effects as a “delusion from the devil.” None of these substances could affect us unless they worked on natural processes in the human brain and made use of the brain’s innate chemical apparatus. Drugs influence and alter how we act and feel because they resemble the brain’s own natural chemicals. This likeness allows them to occupy receptor sites on our cells and interact with the brain’s intrinsic messenger systems.
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But why is the human brain so receptive to drugs of abuse? Nature couldn’t have taken millions of years to develop the incredibly intricate system of brain circuits, neurotransmitters, and receptors that become involved in addiction just so people could get high to escape their troubles or have a wild time on a Saturday night. These circuits and systems, writes a leading neuroscientist and addiction researcher, Dr. Jaak Panksepp, must “serve some critical purpose other than promoting the vigorous intake of highly purified chemical compounds recently developed by humans.”1 Addiction may not be a natural state, but the brain regions it subverts are part of our central machinery of survival. I catch myself edging into a trap here. By writing that addiction “subverts” the brain, I realize I’m feeding the impression that addiction has a life of its own, like a virus invading the body, a predator ready to pounce, or a foreign agent infiltrating an unsuspecting host country. In reality, the constellation of behaviors we call addiction is provoked by a complex set of neurological and emotional mechanisms that develop inside a person. These mechanisms have no separate existence and no conscious will of their own, even if the addict may often experience himself as governed by a powerful controlling force or as suffering from a disease he has no strength to resist. So it would be more accurate to say, Addiction may not be a natural state, but the brain regions in which its powers arise are central to our survival. The force of the addiction process stems from that very fact. Here’s an analogy: let’s say the section of someone’s brain that controls body movements—the motor cortex—was damaged or did not develop properly. That person would inevitably have some kind of physical impairment. If the affected nerves managed nothing more than the motions of the little toe, any loss would hardly be noticeable. If, however, the damaged or undeveloped nerves governed the activity of a leg, the person would have a significant disability. In other words, the impairment would be proportional to the size and importance of the malfunctioning brain center. So it is with addiction. There is no addiction center in the brain, no circuits designated strictly for addictive purposes. The brain systems involved in addiction are among the key organizers and motivators of human emotional life and behavior—hence addiction’s powerful hold on human beings.
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It was in the 1970s that an innate opioid system was first identified in the mammalian brain. The protein molecules that serve as the chemical messengers in this system were named endorphins by the U.S. researcher Eric Simon because they are endogenous—they originate within the organism—and because they bear a resemblance to morphine. Morphine and its opiate cousins fit into the brain’s endorphin receptors and thus, to quote a textbook on addiction research, the main endorphin receptor “represents the molecular gate for opioid addiction.”2 Humans are not the only creatures who have an innate opiate system. We share this pleasure with our near and distant relatives on the evolutionary ladder. Even one-celled organisms produce endorphins. Not surprisingly, endorphins do for us exactly what plant-derived opioids can do: they’re powerful soothers of pain, both physical and emotional. They grant, in the words of that opiate disciple Thomas De Quincey, “serenity, equipoise … the removal of any deep-seated irritation.” For the distracted and soul-suffering person, a hit of endorphins, just like an infusion of opium products, “composes what has been agitated, concentrates what has been distracted.”3 Beyond their soothing properties, endorphins serve other functions essential to life. They’re important regulators of the autonomic nervous system—the part that’s not under our conscious control. They affect many organs in the body, from the brain and the heart to the intestines. They influence mood changes, physical activity, and sleep and regulate blood pressure, heart rate, breathing, bowel movements, and body temperature. They even help modulate our immune system.
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Endorphins are the chemical catalysts for our experience of key emotions that make human life, or any other mammalian life, possible. Most crucially, they enable the emotional bonding between mother and infant. When the natural opioid receptor systems of infant lab animals have been genetically “knocked out,” they’re unable to experience secure connection with their mothers. They’re less distressed when separated from the mother, and this means they can’t give her the signals she needs to act as their nurturer and protector. It’s not that they can’t feel discomfort or fear—they do when exposed to cold or to danger signals such as male mouse odors. But without opioid receptors they can’t maintain the relationship with their mother, on whom their survival depends. They show no interest in their mother’s cues.4 Imagine the peril they would face if they acted indifferently to their mother in the wild. Conversely, young animals—dogs, chicken, rats, and monkeys—who experience separation anxiety on being isolated from their mothers can be soothed by small, nonsedating doses of opiates.5 Endorphins have been well described as “molecules of emotion.”
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B. Kieffer and F. Simonin, “Molecular Mechanisms of Opioid Dependence by Using Knockout Mice,” in Molecular Biology of Drug Addiction, ed. R. Moldano (Totowa, NJ: Human Press, 2003), 12.
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A. Moles, “Deficit in Attachment Behavior in Mice Lacking the Mu-opioid Receptor Gene,” Science, June 25, 2004, 1983–86.
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Panksepp et al., “The Role of Brain Emotional Systems,” 459–69.
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The role of endorphins in human feelings was illustrated by an imaging study of fourteen healthy women volunteers. Their brains were scanned while they were in a neutral emotional state and then again when they were asked to think of an unhappy event in their lives. Ten of them recalled the death of a loved one, three remembered breakups with boyfriends, and one focused on a recent argument with a close friend. Using a special tracer chemical, the scan highlighted the activity of opioid receptors in the emotional centers of each participant’s brain. While the women were under the spell of sad memories, these receptors were much less active.6
- J.-K. Zubieta, “Regulation of Human Affective Responses by Anterior Cingulate and Limbic µ-Opioid Neurotransmission,” Archives of General Psychiatry 60 (2003): 1145–53.
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On the other hand, positive expectations turn on the endorphin system. Scientists have observed, for example, that when people expect relief from pain, the activity of opioid receptors will increase. Even the administration of inert medications—substances that do not have direct physical activity—will light up opioid receptors, leading to decreased pain perception.7 This is the so-called placebo effect, which, far from being imaginary, is a genuine physiological event. The medication may be inert, but the brain is soothed by its own painkillers, the endorphins.
- J. K. Zubieta et al., “Placebo Effects Mediated by Endogenous Opioid Activity on Mu-opioid Receptors,” Journal of Neuroscience 25(34) (August 24, 2005): 7754–62.
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Opiate receptors can be found throughout the body, and in each organ they play a specific role. In the nervous system they are tranquilizers and painkillers, but in, say, the gut, their role is to slow down muscle contractions. In the mouth, they diminish secretions. This is why narcotics taken for pain relief will cause unwanted side effects elsewhere in the body, such as constipation or a dry mouth. Why should there be so many different tasks for one class of natural chemicals? Because Nature, that thrifty homemaker, likes to preserve what is tried and true and to find as many uses as possible for each type of messenger protein. As evolution progressed, systems and substances that had a relatively narrow function in simpler organisms found new arenas of activity in the higher, more complex species that emerged. Many other body chemicals serve multiple purposes—and the more evolved the organism, the more functions a particular substance will have. This is true even of genes: in one type of cell a certain gene will serve one function; elsewhere in the body, it will be assigned quite a different duty. In his book Affective Neuroscience, Dr. Jaak Panksepp gives a fascinating example of the role played in reptiles by vasotocin—a primitive version of the protein oxytocin, which triggers labor contractions and breastfeeding in female mammals.
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Mammalian mothers do not get off so easily—they stay with their helpless young. And oxytocin—a more sophisticated version of vasotocin—plays a much more diverse role than does its reptilian counterpart. It not only induces labor but also affects a mother’s moods and promotes her physical and emotional nurturing of infants. In mammals of both sexes oxytocin also contributes to orgasmic pleasure and, more generally, may be considered one of the “love hormones.” Just like opioids, oxytocin can reduce separation anxiety when infused into distressed young animals.
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Significantly, oxytocin also interacts with opioids. It is not an endorphin, but it increases the sensitivity of the brain’s opioid systems to endorphins—Nature’s way of making sure that we don’t develop a tolerance to our own opiates. (Remember that tolerance is the process by which an addict no longer feels the benefit of previously enjoyable doses of a drug and has to seek more and more.) Why is it essential to prevent tolerance to our natural reward chemicals? Because opioids are necessary for parental love. The infant’s well-being would be jeopardized if the mother became insensitive to the effects of her own opioids. Nurturing mothers experience major endorphin surges as they interact lovingly with their babies—endorphin highs can be one of the natural rewards of motherhood. Given the many thankless tasks required in infant and child care, Nature took care to give us something to enjoy about parenting. Tolerance would more than rob of us those pleasures; it would threaten the infant’s very existence. “It would be disastrous,” writes Dr. Panksepp, “if mothers lost their ability to feel intense social gratification from nurturance when children were still quite young.”9 By making our brain cells more sensitive to opioids, oxytocin allows us to remain “hooked” on our babies. Opiates, in other words, are the chemical linchpins of the emotional apparatus in the brain that is responsible for protecting and nurturing infant life. Thus addiction to opiates like morphine and heroin arises in a brain system that governs the most powerful emotional dynamic in human existence: the attachment instinct. Love. Attachment is the drive for physical and emotional closeness with other people. It ensures infant survival by bonding infant to mother and mother to infant. Throughout life the attachment drive impels us to seek relationships and companionship, maintains family connections, and helps build community. When endorphins lock onto opiate receptors, they trigger the chemistry of love and connection, helping us to be the social creatures we are. It may seem puzzling that Nature would have given one class of chemicals the apparently very different tasks of alleviating physical pain, easing emotional pain, creating parent–infant bonds, maintaining social relationships, and triggering feelings of intense pleasure. In fact, the five roles are closely allied.
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Opiates do not “take away” pain. Instead, they reduce our consciousness of it as an unpleasant stimulus. Pain begins as a physical phenomenon registered in the brain, but we may or may not consciously notice it at any given moment. What we call “being in pain” is our subjective experience of that stimulus (i.e., “Ouch, that hurts”) and our emotional reaction to the experience. Opiates help make some pain bearable. It has been suggested, for example, that high levels of endorphins help toddlers endure the many bumps and minor bruises they sustain on their rambunctious adventures. It’s not that a toddler’s injuries don’t cause pain; they do. But partly because of endorphins, the pain isn’t enough to discourage him. Without a high level of endorphins he might even want to stop his explorations of the world, so necessary for learning and development.10 A child who complains bitterly of the slightest hurt and is often accused of being a “crybaby” is probably low on endorphins and is likely to be less adventurous than his peers.
- A. N. Schore, Affect Regulation and the Origin of the Self (Hillsdale, NJ: Lawrence Erlbaum Associates, 1994), 142–43.
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Anatomically, physical pain is registered in one part of the brain, the thalamus, but its subjective impact is experienced in another part, the anterior cingulate cortex, or ACC. The brain gets the pain message in the thalamus but feels it in the ACC. This latter area “lights up,” or is activated, when we are reacting to the pain stimulus. And it’s in the cortex—the ACC and elsewhere—that opiates help us endure pain by reducing not its physical but its emotional impact. A recent imaging study showed that the ACC also lights up when people feel the pain of social rejection.11 The brains of healthy adult volunteers were scanned as they were mentally participating in a game and then suddenly “excluded.” Even this mild and obviously artificial “rejection” lit up the ACC and caused feelings of hurt. In other words, we “feel” physical and emotional pain in the same part of the brain—and that, in turn, is crucial to our bonding with others who are important to us. In normal circumstances, the emotional pain of separation keeps us close to each other when we most need that closeness.
- N. I. Eisenberger, “Does Rejection Hurt? An FMRI Study of Social Exclusion, Science, October 10, 2003, 290–92.
Note: acc is second dart
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Why did Nature make the mammalian opioid system responsible for our reactions to both physical and emotional pain? For a very good reason: the complete helplessness of the young mammal and its absolute dependence on nurturing adults. Physical pain is a danger alarm: if a child wakes up with a tummy ache, her ACC goes into overdrive, and she’ll give every possible signal to call her caregivers promptly to her side. For the infant mammal, emotional pain is an equally essential warning: it alerts us to the danger of separation from those we depend on for our very lives. Feeling this emotional pain triggers infant behaviors—ultrasonic vocalization in rat pups, pitiful crying in human babies—designed to bring the parent back. The attentive presence of the nurturing adult will trigger endorphin release in the infant’s brain, helping to soothe her.
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A child can also feel emotional distress when the parent is physically present but emotionally unavailable. Even adults know that kind of pain when someone important to us is bodily present but psychologically absent. This is the state the seminal researcher and psychologist Allan Schore has called “proximal separation.”12 Given that the child’s dependence is as much emotional as physical, in normal circumstances a child who senses emotional separation will seek to reconnect with the parent. Once more, the parent’s loving response will flood the brain with endorphins and ease the child’s discomfort. Should the parent not respond, or not respond adequately, endorphins won’t be released, and the child will be left to his own inadequate coping mechanisms—for example, rocking or thumb-sucking as ways of self-soothing or tuning out to escape distress. Children who have not received the attentive presence of the parent are, as we will see, at greater risk for seeking chemical satisfaction from external sources later in life.
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In keeping with Nature’s efficient, multipurpose “recycling” of chemical substances, endorphins are also responsible for experiences of pleasure and joyful excitement. Like infants and mothers, lovers, spiritual seekers, and bungee jumpers—yes, bungee jumpers—all reach euphoric states in which endorphins play a key role. One study found that endorphin levels tripled in the blood of bungee jumpers for the half-hour following the leap and were correlated with the degree of reported euphoria: the higher the endorphin levels, the greater the euphoric feelings.13
- J. Hennig et al., “Biopsychological Changes after Bungee Jumping: Beta-Endorphin Immunoreactivity as a Mediator of Euphoria?” Neuropsychobiology 29(1) (1994): 28–32.
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While the brain’s opiate receptors are the natural template for feelings of reward, soothing, and connectedness, they are also triggered by narcotic drugs, and they play a role in other addictions, too. In a study of alcoholics, opioid receptor activity was diminished in several brain regions, and this was associated with increased alcohol craving.14 The activation of opioid pathways and the resulting increased endorphin activity also enhances cocaine’s effects.15 As with alcohol, less endorphin activity means a greater desire for cocaine. Activation of opiate receptors contributes to the pleasures of marijuana use as well.16
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B. Bencherif et al., “Mu-opioid Receptor Binding Measured by [11C]car-fen-tanil Positron Emission Tomography Is Related to Craving and Mood in Alcohol Dependence,” Biological Psychiatry 55(3) (February 1, 2004): 255–62.
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D. A. Gorelick et al., “Imaging Brain Mu-opioid Receptors in Abstinent Cocaine Users: Time Course and Relation to Cocaine Craving,” Biological Psychiatry 57(12) (June 15, 2005): 1573–82.
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N. S. Miller and M. S. Gold, “A Hypothesis for a Common Neurochemical Basis for Alcohol and Drug Disorders,” Psychiatric Clinics of North America 169(1) (1993): 105–17.
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In short, the life-foundational opioid love/pleasure/pain relief apparatus provides the entry point for narcotic substances into our brains. The less effective our own internal chemical happiness system is, the more driven we are to seek joy or relief through drug-taking or through other compulsions we perceive as rewarding.