What you know about the neurotransmitter dopamine is probably wrong

NEW YORK – The neurotransmitter dopamine is eliciting a lot of panic these days.

According to books, articles and social media posts, people’s urge for a quick dopamine hit is why they crave cookies and spend too much time on Instagram.

If they keep giving in to these desires, the rationale goes, they will never be able to stop themselves.

“We’ve transformed the world from a place of scarcity to a place of overwhelming abundance,” Dr Anna Lembke, a Stanford University psychiatrist, wrote in her best-selling book Dopamine Nation.

Consequently, people are all at risk for “compulsive overconsumption”.

A self-improvement trend often called “dopamine fasting” that emerged in 2019 revolves around abstaining from anything that causes the release of the chemical.

The premise is that modern-day entertainment rewires the brain so that slower-paced pastimes are no longer pleasurable.

Videos tagged #dopamine, many claiming to teach viewers how to manipulate the brain chemical, have more than 700 million views on TikTok. One influencer offers a “free list of things that numb dopamine” so that you can “reclaim control over your life”.

Parents are even advised to prevent children from experiencing spikes in dopamine (meaning not to let them play video games or eat junk food), lest the insatiable need for the neurotransmitter increases bad behaviour.

Scientists who study dopamine say these concerns have been blown out of proportion.

They “are not necessarily based on actual science of what we know about dopamine”, said assistant professor of neurology Vijay Namboodiri at the University of California, San Francisco.

Before you swear off dopamine – and the prospect of any joy in life – it is important to understand the biggest misconceptions about the neurotransmitter and what the research shows.

Dopamine is not inherently good or bad

The idea that dopamine produces feelings of pleasure came from early experiments in rodents, and later humans, that found the dopamine system was activated when animals encountered a reward.

Food, sex, drugs and social interactions all set off releases of dopamine in the brain, suggesting the neurochemical is linked to a feel-good outcome.

But upon further study in the 1990s, scientists realised that dopamine is more closely related to the anticipation of a reward than to its receipt.

Dopamine causes the wanting of something and the motivation to go and get it, not the enjoyment of it.

“What we think it maybe does is something like desire,” said assistant professor of neuroscience Talia N. Lerner at Northwestern University. “It teaches your brain how to predict your needs and try to align your behaviours with those needs.”

A neurochemical that controls desire can sound sinister, but pursuing rewards is not inherently a problem. It all depends on the context. Animals from honeybees to humans developed dopamine systems to motivate them to seek out food and sex to survive and procreate.

“It’s an important part of why we’re here today,” said professor of psychology and neuroscience Kent Berridge at the University of Michigan. “We wouldn’t have evolved and we wouldn’t have survived, our ancestors, without dopamine.”

Dopamine is also essential for learning. In this context, the key element that causes dopamine neurons to fire is surprise, regardless of whether the outcome is rewarding or disappointing.

“Dopamine tells you not when something is good or bad per se, but when it’s better or worse than you expected it to be,” Prof Lerner said.

That surge of dopamine helps you update your expectations and potentially modify your behaviour for the future.

A normal hit of dopamine is not going to rewire your brain

Because of dopamine’s role in motivation and learning, the worry is that highly stimulating activities will hijack the neurotransmitter system, such that it no longer works for smaller, everyday rewards.

For someone hooked on video games, the thinking goes, Monopoly might be less rewarding.

This concern is partly based in science.

Prolonged use of drugs that cause huge surges in dopamine, such as cocaine and amphetamine, can cause the brain to shut off some of the receptors that the neurochemical acts on. This so-called tolerance means that more of the drug is required to achieve the same high.

Because video games and pornography can be habit-forming, some researchers, including Dr Lembke, have hypothesised that they might cause similar signs of tolerance in the brain.

However, in an interview with The New York Times, she admitted that this theory is inferred from studies of stimulant drugs and that there is currently no evidence to back it up.

As a result, Prof Berridge and others have critiqued the idea.

One reason is that the amount of dopamine released in response to video games, pornography, social media and junk food is substantially lower than that released in response to addictive drugs.

And while, for some people, video games cause a greater dopamine response than board games do, that does not mean the board game causes a smaller dopamine release than it used to, and it is not because of an inherent change in the dopamine system, Prof Namboodiri said.

It also does not mean that video game lovers will never want to play board games again. The same goes for eating candy versus eating fruit or watching YouTube versus reading a book.

Addiction is about more than dopamine

Some rewarding behaviours can cause problems in people’s lives.

Although activities such as gambling, watching pornography and playing video games do not stimulate as much dopamine release as drugs do, they can lead to patterns of behaviour similar to those seen in substance use disorder – namely, continuing the activity despite severe negative consequences.

But that is the exception, not the rule.

Most people are not losing their jobs or relationships or experiencing negative health impacts because of these activities.

Roughly 2 to 3 per cent of people who watch pornography report being addicted to the behaviour.

Similarly, 2 to 3 per cent of people who play online games qualify as having Internet gaming disorder.

“For some people, yes, this is a problem,” Prof Berridge said. “It’s not a problem for most people. We can function in the world and enjoy this reward-rich world.”

As with most things related to health, the key is moderation. You do not have to deny yourself pleasure to be a good or healthy person.

And while dopamine is involved in addiction, compulsions to, say, use drugs are more complicated than a single neurotransmitter.

“To say that it’s only dopamine is an oversimplification,” Dr Lembke said. NYTIMES