In the Realm of Hungry Ghosts: Close Encounters with Addiction

by Gabor Maté

the part of the cerebral cortex responsible for regulating emotional impulses and for making rational decisions, addicted brains have reduced activity.

An imaging study of rhesus monkeys published in 2006 confirmed previous findings that the number of receptors for dopamine was reduced in chronic cocaine users.

Cocaine and other stimulant-type drugs work because they greatly increase the amount of dopamine available to cells in essential brain centers. That sudden rise in the levels of dopamine, one of the brain’s “feel-good” chemicals, accounts for the elation and sense of infinite potential experienced by the stimulant user, at least at the beginning of the drug habit.

On the cellular level addiction is all about neurotransmitters and their receptors. In different ways, all commonly abused drugs temporarily enhance the brain’s dopamine functioning. Alcohol, marijuana, the opiates heroin and morphine, and stimulants such as nicotine, caffeine, cocaine, and crystal meth all have this effect.

Cocaine’s action may be likened to that of the antidepressant fluoxetine (Prozac). Prozac belongs to a family of drugs that increase the levels of the mood-regulating neurotransmitter serotonin between nerve cells by blocking its reuptake. They’re called selective serotonin reuptake inhibitors, or SSRIs. Cocaine, one might say, is a dopamine reuptake inhibitor. It occupies the receptor on the cell surface normally used by the brain chemical that would transport dopamine back into its source neuron. In effect, cocaine is a temporary squatter in someone else’s home.

Unlike Prozac, cocaine is not selective: it also inhibits the reuptake of other messenger molecules, including serotonin.

Crystal meth both releases dopamine, like nicotine, and blocks its reuptake, like cocaine. The power of crystal meth to rapidly multiply dopamine levels is responsible for its intense euphoric appeal.

Activities such as eating or sexual contact also promote the presence of dopamine in the synaptic space. Dr. Richard Rawson, associate director of the University of California, Los Angeles’s Integrated Substance Abuse Program, reports that food seeking can increase brain dopamine levels in some key brain centers by 50 percent. Sexual arousal will do so by a factor of 100 percent, as will nicotine and alcohol.

When the brain is diseased, the functions that become pathological are the person’s emotional life, thought processes, and behavior. And this creates addiction’s central dilemma: if recovery is to occur, the brain, the impaired organ of decision making, needs to initiate its own healing process. An altered and dysfunctional brain must decide that it wants to overcome its own dysfunction: to revert to normal—or, perhaps, become normal for the very first time.

The scientific literature is nearly unanimous in viewing drug addiction as a chronic brain condition, and this alone ought to discourage anyone from blaming or punishing the sufferer. No one, after all, blames a person suffering from rheumatoid arthritis for having a relapse, since relapse is one of the characteristics of chronic illness.

All the substances that are the main drugs of abuse today originate in natural plant products and have been known to human beings for thousands of years.

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.”

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.”

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.

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.

Humans are not the only creatures who have an innate opiate system. We

Not surprisingly, endorphins do for us exactly what plant-derived opioids can do: they’re powerful soothers of pain, both physical and emotional.

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 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.

But without opioid receptors they can’t maintain the relationship with their mother, on whom their survival depends. They

Endorphins have been well described as “molecules of emotion.”

Reinforcement is important in all addictions, drug-related or not. In

dopamine is flowing. The incentive is powerful.

Needless to say, life-essential reinforcers such as food and sex trigger VTA activation and dopamine release in the NA, since the performance of survival-related behaviors is the very purpose of the incentive-motivation system.

In other words, nerve fibers in the VTA are triggering dopamine release in the NA when a person needs to know, “Is this new whatever-it-is going to help me or hurt me? Will I like it or not?” The role of the dopamine system in novelty-seeking helps explain why some people are driven to risky behaviors such as street racing.

Why is this relevant? First, as I’ve already explained, chronic cocaine use reduces the number of dopamine receptors and thereby keeps driving the addict to use the drug simply to make up for the loss of dopamine activity.

More importantly, research now strongly suggests that the existence of relatively few dopamine receptors to begin with may be one of the biological bases of addictive behaviors.

As we have now seen, addiction inevitably involves both opioid and dopamine circuitry. The dopamine system is most active during the initiation and establishment of drug intake and other addictive behaviors. It is key to the reinforcing patterns of all drugs of abuse—alcohol, stimulants, opioids, nicotine, and cannabis.

Opioid circuits and dopamine pathways are important components of what has been called the limbic system, or the emotional brain. The circuits of the limbic system process emotions like love, joy, pleasure, pain, anger, and fear. For all their complexities, emotions exist for a very basic purpose: to initiate and maintain activities necessary for survival.

When impaired or confused, as it often is in the complex and stressed circumstances prevailing in our “civilized” society, the emotional brain leads us to nothing but trouble. Addiction is one of its chief dysfunctions.

“That’s a choice you’re making,” I reply. Even as the words leave my lips, I know I’m mouthing a platitude. From a certain point of view, everything we do is a choice. From a scientific perspective, though, Claire is closer to the mark. Her explanation that she is addicted—and that therefore her drug use is not the result of thoughtful deliberation—fits with the research evidence.

“Recent studies have shown that repeated drug use leads to long-lasting changes in the brain that undermine voluntary control,”

In other words, drug addiction damages the parts of the brain responsible for decision making.

consider scientific evidence suggesting that addiction also disrupts the self-regulation circuits—which the addict needs in order to choose not to be an addict.

In general, the higher in the brain we ascend physically, the more recent are the brain centers in evolutionary development and the more complex their functions.

As a human being matures, higher brain systems come to exert some control over the lower ones.

The most recently evolved part of the cortex, distinguishing us from other animals, is the prefrontal cortex, the gray matter area in the front of the brain.

It’s a simplification, but an accurate one, to say that the frontal cortex—and particularly its prefrontal portions—acts as the chief executive officer of the brain. It is here that alternatives are weighed and choices considered. It is also here that emotionally driven impulses to act are evaluated and either given permission to go ahead or—if necessary—inhibited.

impaired PFC function will have poor impulse control and will behave in ways that to others seem uncalled for, childish, or bizarre.

Through its rich connections with the limbic (emotional) centers, the OFC is the apex of the emotional brain and serves as its mission control room.

The neurological traces of early, formative events are embedded in the OFC, which, in turn, is connected with other memory-serving brain structures.

Connections and circuits used frequently are strengthened, while unused ones are pruned out: indeed, scientists call this aspect of neural Darwinism synaptic pruning.

In large part, an infant’s early years define how well her brain structures will develop and how the neurological networks that control human behavior will mature.

In many other cases it’s not a question of “bad stimulation” but of a lack of sufficient “good stimulation.”

In the case of these circuits, which process emotions and govern behavior, it is the emotional environment that is decisive. By far the dominant aspect of this environment is the role of the nurturing adults in the child’s life, especially in the early years.

The third prime necessity—emotional nurture—is the one most likely to be disrupted in Western societies. The importance of this point cannot be overstated: emotional nurturance is an absolute requirement for healthy neurobiological brain development.

The child needs to be in an attachment relationship with at least one reliably available, protective, psychologically present, and reasonably nonstressed adult.

To begin to grasp the matter, all we need to do is picture a child who was never smiled at, never spoken to in a warm and loving way, never touched gently, never played with. Then we can ask ourselves: What sort of person do we envision such a child becoming?

Infants read, react to, and are developmentally influenced by the psychological states of the parents.

In a very real sense, the parent’s brain programs the infant’s, and this is why stressed parents will often rear children whose stress apparatus also runs in high gear, no matter how much they love their child and no matter that they strive to do their best.