WHEN YOU HEAR that little ping or buzz–or whatever sound indicates that a new message has arrived on your mobile device–both the anticipation of a reward and the unpredictability of what message you will see stimulate the brain’s dopamine system to increased excitement and activity. Tweets are the most addictive because the information is too small to fully satisfy, another stimulation booster.
Dopamine, a brain hormone that functions as a neurotransmitter, has always been thought of as the “feel-good messenger” and “controller of the body’s pleasure system.” But new evidence consigns feelings of pleasure to the opioid system, while dopamine makes us want and search; makes us attentive, curious, aroused and goal-directed. Even with food nearby, rats with their dopamine neurons removed will starve. The dopamine system is stronger than the opioid system, making us continue to seek even when we are satisfied.
Dopamine is released in response to the promise of rewards– sex, money, drugs, novel situations–and tells your brain something like “pay attention,” writes Richard Friedman, psychiatrist and pharmacologist at Weill Cornell Medical College in New York, in a recent New York Times article about attention deficit hyperactivity disorder (ADHD).
Both texting and the Internet in general, because they provide almost instantaneous gratification, can create a “dopamine-induced loop,” making it increasingly more difficult to stop checking to see if something new has arrived. Such distractions are more compelling in the midst of a much less exciting task or meeting, especially those that should not be interrupted to read tweets.
Adults with ADHD have significantly fewer dopamine receptors–making their reward circuits less sensitive–compared to healthy controls, according to research by Nora Volkow, director of the National Institute on Drug Abuse. These adults respond better to anything varied and unpredictable, and can find repetitive and routine tasks so unrewarding as to become “painfully boring,” Friedman writes. In short, he says, “People with ADHD may not have a disease so much as a set of behavioral traits that don’t match the expectations of our contemporary culture.”
Friedman notes the enormous increase in childhood ADHD diagnoses and treatment: from 2003 to 2011, rising from 7.8 to 11 percent of the population–“a whopping 41 percent increase;” and he points to an “increasingly stark contrast between the regimented…school environment and the highly stimulating digital world.” ADHD occurs in 3.5 percent of adults, a much smaller percent possibly because adults have greater freedom to choose activities suited to their interests.
What helps both kids and adults with ADHD is selecting “situations that are a better fit for their novelty-seeking behavior,” for example: those with hands-on learning, self-paced computer assignments and tasks that build specific skills. Also helpful are small goals, such as making it through the morning without checking Facebook.
Dopamine also appears in the perennial argument about the benefits of breakfast. A study of 16 overweight 19-year-old females found that those who ate a high-protein breakfast had a 34-fold reduction in cravings for high-fat foods. Complex proteins raise levels of tyrosine, which leads to increased production of dopamine–which in turn regulates food cravings and intake.
Because dopamine levels are blunted in individuals who are overweight, it takes more food to elicit feelings of reward. Elevating dopamine via high-protein meals can make it easier to resist carbohydrates, such as pancakes or that mid-morning croissant, which are especially tempting when the body’s blood sugar is low after a night’s sleep.
(A previous study on 300 typical-weight people, however, showed no difference in weight over time between those who skipped or ate breakfast. Other research found that breakfast-skippers ate less over the course of the day than breakfast-eaters, though they also burned fewer calories.)
Stress and lack of sleep deplete dopamine, and variable dopamine levels can create peaks and crashes. Consuming tyrosine-rich foods, such as fava beans, edamame, almonds, avocados, bananas and sesame and pumpkin seeds, in addition to a high-protein diet, may help stabilize dopamine levels.
Exercise can also help by increasing blood levels of calcium, which in turn helps stimulate dopamine levels. Exercise also ups the body’s endorphins, which can provide good feelings when your dopamine is low–as can stretching and laughing.