Many people assume marijuana or alcohol, but psychoactive substances include anything that has a significant effect on mental processes. Caffeine, a drug present in coffee, stimulates the central nervous system, improves mental alertness, and is the most widely-consumed psychoactive drug in the world.
How The Monkey Got on Your Back
The science of getting hooked.
We think of smoking and drinking as vices that are hard to control. But a few years ago, when University of Chicago researchers studied 205 German adults who carried BlackBerry mobile devices, they actually found that it was far tougher for them to resist the urge to send tweets or check their emails throughout the day. In fact, people were more likely to give in to their craving for electronic media than they were to succumb to the allure of sleep or sex.
What is even more amazing, however, is the frequency of cravings for satisfaction of all sorts. The subjects, who were contacted by researchers 7 times a day over a two-week period and asked if they had experienced a desire in the past 30 minutes, reported feeling such cravings 74 percent of the time. As lead author Wilhelm Hofmann explained: "Modern life is a welter of assorted desires, marked by frequent conflict and resistance, the latter with uneven success."
When we hear the word addiction, we tend to envision horrific images involving illegal drugs, such as a sweaty, trembling heroin addict who is frantically trying to score a fix to satisfy the metaphorical monkey on his back. But that nightmarish compulsion is just the extreme manifestation of something we all frequently experience, a chemical system that rewards certain behaviors—whether it's watching funny YouTube videos, perusing Facebook, or checking our phones eagerly every time we hear the ding of an arriving email or text—and conditions us to repeat them over and over.
Scientists believe that the same mechanism that leads to addiction evolved in early humans for a positive purpose, to link pleasure to activities beneficial to the species' survival. In modern civilization, that feedback loop sometimes runs amok, and our capacity to develop compulsions can be manipulated by those who want to sell us things. But new discoveries also offer more hope of taming the monkeys on our backs.
The Neurobiology of Addiction
Recent research suggests that about 10 to 15 percent of people may have a genetic predisposition that makes them more vulnerable to dangerous types of addiction, such as drug abuse, alcoholism,
gambling, or burning through our earnings with compulsive shopping. But we've all got the basic wiring to become hooked on something, even if it's just posting cute cat videos to Facebook.
When you do get the urge to do something that you think of as enjoyable or satisfying, it's actually your brain that is creating the allure of pleasure, by releasing a neurotransmitter called dopamine, which enables impulses to pass through the tiny space between one neuron and another. Dopamine creates a number of different pathways in the brain. But probably the most important one is the mesolimbic pathway, connecting the ventral tegmental area, a primitive section deep in the brain, with a bunch of other important brain structures, including ones involved with memory, mood and choice-making. A single squirt of dopamine from a neuron can give a jolt to 10,000 or more other brain cells. The dopamine circuitry, in turn, interacts with a second system, the opioid system, which produces chemicals that cause the actual sensation of pleasure.
When you're thinking about dopamine, you may want to hum that old Carly Simon song "Anticipation," because that's what she was singing about, even if she didn't realize it. Dopamine levels actually spike before we do a pleasurable activity, and because the dopamine system actually is more powerful than the opioid system, that dopamine drop-off afterward prods us to repeat the activity over and over.
Moreover, when we engage in a pleasurable activity, we condition our brains to produce dopamine the next time that we're getting ready to do it. "If you, say, have learned to associate a cue like a crack pipe with a hit of crack, you will start getting increases in dopamine in the nucleus accumbens [a brain structure] in response to the sight of the pipe, as your brain predicts the reward," neuroscientist Bethany Brookshire explained in a 2013 article for Slate. "But if you then don't get your hit, well, then dopamine can decrease, and that's not a good feeling."
The frontal lobe of your cerebral cortex, the part that processes narratives, also contains the highest number of dopamine receptors. That's one reason why you'll watch a silly YouTube video to see what happens at the end, and why those unresolved story arcs in your favorite police drama keep you tuning in, week after week.
Stress also can trigger the dopamine circuit as well. That's why former drug addicts and alcoholics often relapse after they undergo some personal crisis, such as a divorce or job loss. That also may explain why after a particularly trying day at the office, you go home and spend hours on YouTube or Facebook.
The Evolutionary History of Cravings
The same chemical process that gives a drug addict that ecstatic rush also is triggered when you do something more benign, whether it's eating something delicious, learning a new skill or exploring a new
place. Evolutionary biologists theorize that the reward system developed in order to encourage our ancestors to do things that helped humanity to survive and grow.
Dopamine probably played an important role in spurring our ancestors to go after food. Studies have found that when rats' ability to utilize dopamine is impaired, they will neglect to eat and starve to death, even when the food easily available right beside them. "They have lost the anticipation and desire to go get the food," behavioral psychologist Susan Weinschenk explains in a 2012 Psychology Today blog post.
Dopamine also can drive a craving for new information—as evidenced by how easy it is to fall into compulsively doing Google searches on arcane subjects. "It is possible for the dopamine system to keep saying "more more more", causing you to keep seeking even when you have found the information," Weinschenk writes.
A study published in Journal of Neuroscience in 2013 reported that people with a genetic variation that caused their brains to respond less intensely to dopamine—a characteristic that might lead them to seek more stimulation that those with high dopamine receptivity—seem to be strongly associated with longevity. The variation was 66 percent more common among people ages 90 and older than it was in a younger comparison group. While the sensation seekers had a tendency to engage in high-risk activities such as dangerous driving and sexual promiscuity, they also had a higher tendency to remain physically active as they got older.
It's Not Just About Drugs or Booze
But it doesn't take a hit from a crack pipe or a gulp of cheap wine to activate the body's pleasure feedback system. In an article published in the journal Cyberpsychology, Behavior, and Social Networking in 2011, researchers measured the physiological response of people who used Facebook, and reported that the social networking site could induce "a psychophysiological state characterized by high positive valence and high arousal."
In an experiment conducted for Brain Games, subjects waiting to watch a movie preview had to relinquish their cell phones to an attendant, who put them in a container. After the attendant left the room, the subjects heard their phones ringing and chirping, and started to get antsy. On average, they were able to hold out for only 12 minutes before retrieving their devices to check them.
That's consistent with a 2010 study by marketing experts Martin Lindstrom and Elias Arts, who monitored the pupil, brainwave and facial muscle activity of subjects as they listened to 50 different sounds. Next to a baby's giggle, the sound that produced the most arousal was that of a vibrating cell phone, they found.
Norwegian researchers actually have developed a Bergen Facebook Addiction Scale, which measure the extent of users' compulsion to use the social network website.
Pop songwriters and producers work hard to fill songs with what neuroscientists call "earworms"—that is, simple binary rhythms and repetitive melodies to which listeners' brains can become addicted. In the early 2000s, a study by University of Cincinnati researchers found that 98 percent of subjects, at one time or another, found themselves annoyed by a song that they couldn't get out of their heads, such as the Village People's "YMCA" or the Baha Men's "Who Let the Dogs Out?"
Taming the Monkey
Because addictions train your brain to react, kicking them isn't just a matter of willpower. "It's like putting on a lot of weight," Stanford University psychiatry and behavioral science professor Keith Humphreys explained in a 2012 article. "Your body changes, and from then on losing weight is way harder than it ever was before you got fat in the first place." And because the changes are persistent, quitting a vice often requires a long-term process.
In a study presented at the Canadian Neuroscience Meeting in 2014, McGill University researcher Jonathan Britt reported that a new technology called optogenetics, which uses light-responsive proteins to show the activation of neural circuits in the brain, can show the specific dopamine pathways that are connected with specific habitual behaviors. In the future, that may enable scientists to develop treatments that suppress those pathways and curb various addictions.
But if it's Twitter and email that are stimulating your cravings, Behavioral psychologist Weinschenk writes that it's possible to curb the dopamine feedback system simply by turning off the cues. "Adjust the settings on your cell phone and on your laptop, desktop or tablet so that you don't receive the automatic notifications," she writes. Those beeps "are actually causing you to be like a rat in a cage."
- About the same
- Two times as likely
- Three times as likely
- Five times as likely
- Answer: Two times as likely
- Fluctuations in blood sugar
- Less dopamine produced
- Death of brain cells
- Answer: Less dopamine produced
- The brain stem
- The cerebral cortex
- The limbic system
- Broca’s area
- Answer: The limbic system
How To Become Addicted
...But in a good way!
In the main article above titled "How The Monkey Got on Your Back," we discussed how our brains are equipped with a chemical reward system that encourages us to repeat various behaviors over and over. When people use the word addiction, they usually mean some negative behavior, whether it's smoking cigarettes or using drugs, or playing excessive amounts of video games. But what if you turned the same mechanism to your advantage, and tried to develop an addiction to something beneficial?
Back in the 1970s, psychiatrist Dr. William Glasser advanced the notion of "positive addiction," in which he advocated making a habit of beneficial activities such as running and meditation, as a bulwark against self-destructive habits. Glasser reasoned that positive addictions, because they required a person to develop inner strength, would help banish the craving for pleasure and relief from stress that bad habits often provide. Here are some tips for developing a positive addiction, based upon his work:
- Find an activity that is non-competitive, to which you can devote an hour each day.
- Pick an activity with a rhythm that leads to a feeling of satisfaction, such as the movements and footsteps of running.
- Pick an activity that you believe has some spiritual, mental or physical value.
- Pick something that you can do alone, without others, so that you don't depend upon them.
- Believe that if you persist in practicing your chosen activity, you will eventually improve.
- Avoid self-criticism. You have to completely accept yourself.