Skip to content

How Negative Thoughts Affect Brain Health + What To Do About Them

Daniel Amen, M.D.
October 17, 2019
Daniel Amen, M.D.
Clinical neuroscientist psychiatrist
By Daniel Amen, M.D.
Clinical neuroscientist psychiatrist
Daniel Amen, MD, is a clinical neuroscientist psychiatrist, physician, professor and 10-time New York Times bestselling author. He is a double board-certified child and adult psychiatrist and founder of Amen Clinics, Inc.
October 17, 2019

Here's something to ponder. Every time you have a thought—and it's estimated that about 60,000 of them ricochet through your mind each day—your brain pumps out chemicals that influence the way you feel. And it happens almost instantly.

Whenever you have a sad thought, an unkind thought, or a hopeless thought—such as "I'm never going to land my dream job"—your brain pumps out a dose of chemicals that make you feel bad. On the flip side, conjure a happy, loving, or encouraging thought, and your brain gives you a blissful jolt of feel-good chemicals.

It seems obvious that if you want to feel better, you should consciously fill your head with hopeful thoughts. But most of us have no control over our thoughts. They pop in automatically, and they're overwhelmingly negative. These automatic negative thoughts (ANTs) infest the brain and steal your happiness.

Think of these ANTs as you would the ants that might bother you if you were on a romantic picnic. One ANT, like one pesky critter at your picnic, is no big problem. Two or three ANTs, like two or three insects at your picnic, become a bit more irritating. But having hundreds of ANTs, like hundreds of creepy-crawlers at your picnic, can ruin your day. 

These ANTs are bad news for your brain too.

How ANTs affect the brain.

Several years ago, I did a brain imaging study comparing the effects of both ANTs and gratitude on brain function. For this study, we performed two brain scans on the same woman—one while she was contemplating everything she was grateful for in her life and another while her head was filled with negativity—ANTs.

The first scan revealed that gratitude and healthy thinking enhanced brain function. The regions of her brain associated with mood looked calm with optimal activity.

For the second scan, we asked her to focus on sad, frightening, worrisome ANTs. She imagined her beloved dog getting sick and dying. She worried about losing her job and running out of money. And she envisioned becoming homeless. Scary stuff.

Her second scan showed that her brain on negativity looked vastly different from that healthy scan. In particular, two important brain regions showed a serious and concerning decrease in activity.

First, it looked like her cerebellum, usually one of the most active areas of the brain, had gone on strike. Located at the back of the brain, the cerebellum is involved in motor coordination and thought organization and is essential for processing complex information. When this region is underactive, people tend to be clumsier—both in their physical movement and in their cognitive processes.

Second, the activity in her temporal lobes plummeted from all that negative thinking. The temporal lobes play an important role in mood, memory, and temper control. Decreased activity here is associated with some forms of depression, as well as memory problems, dark thoughts, and even violence.

The long-term effects of negative thinking.

The link between our thoughts and brain activity has been noted for decades. As early as 1995, researchers at the National Institute of Mental Health were using neuroimaging to investigate how thoughts affect brain function1. They put healthy women in a functional brain scanner and peered inside their skulls to see what happened when they filled their minds with happy thoughts, sad thoughts, and neutral thoughts.

When thinking happy thoughts, activity in their emotional brain cooled off, and they reported feeling better. When they focused on sad thoughts, their emotional brain fired up with more activity, a pattern that is associated with depression.

These effects aren't short term. Negative thinking effectively rewires our neural networks2, strengthening pathways in the brain to make us more likely to continue seeing the glass as half-empty. Our brain-imaging work shows that feeling bad further affects the brain, reducing activity in an area involved with self-control, judgment, and planning. This increases the odds of making bad decisions, which leads to more ANTs, which makes you feel worse. It's a downward spiral that can take a serious toll on your well-being.

The more you allow the ANTs to stick around in your head, the more likely you are to feel anxious, depressed, or angry, and the higher your chances of having troubles at work, in relationships, or at school.

Warning: Your ANTs are lying.

Don't believe everything you think. Not only do ANTs disrupt optimal brain function, but they also tend to lie. Actually, they lie a lot and can wreak havoc in your life. In my new book, Change Your Brain, Change Your Grades, I write about Marcus, a 14-year-old who thought he was stupid and berated himself daily for having trouble with his schoolwork and doing poorly on tests. But he had an IQ of 135, placing him in the top 1% of all people. He wasn't stupid, but he did need to stop believing every stupid ANT that popped into his head.

I told Marcus how important it is to examine your thoughts to see if they are true and if they are helping you or hurting you. Unfortunately, if you never challenge your thoughts, you will simply believe them, and the ANTs will rule your brain and ruin your life.

Learn the 7 Types of ANT Species.

You can learn to eliminate the ANTs and replace them with more helpful thoughts that give you a more accurate, fair assessment of any situation. This skill can completely change your life if you embrace and practice it. The first step is learning to identify the seven ANT species:


All-or-nothing ANTs

These sneaky ANTs think in absolutes—things are all good or all bad—and use words like all, always, never, none, nothing, no one, everyone, and every time. If you hear yourself thinking, "No one ever listens to me," you may have an all-or-nothing infestation.


Just the bad ANTs

This ANT can't see anything good! It seeks out the bad side of everything. It can find mistakes anywhere and roots out problems in even the most drama-free situations. People whose heads are filled with these ANTs are likely to say something along the lines of: "We went on a weeklong vacation to Hawaii, but I got a sunburn, so it sucked."


Guilt-beating ANTs

These ANTs think in words like should, must, ought to, or have to. In my 35 years as a psychiatrist, I have found that guilt is generally not a helpful motivator of behavior. It often backfires and can be counterproductive to your goals. Instead of saying, "I should give up sugar," it's better to think something like, "Getting off sugar will help me reach my health goals and avoid the emotional roller coaster."


Labeling ANTs

Attaching negative labels to yourself or someone else inhibits your ability to see people and situations for who or what they really are. By calling someone a jerk, for example, you basically lump that person in your mind with all of the jerks you've ever known, and you become unable to deal with them in a reasonable way.


Fortune-teller ANTs

Don't listen to this lying ANT! Fortune-teller ANTs think they can see into the future, and they predict the worst possible outcome for every situation. ANTs like "I'm going to blow my SATs, and I'll never get into college" can become self-fulfilling prophecies.


Mind-reader ANTs

This ANT thinks it can see inside someone else's mind to know what they're thinking. ANTs like "Did you see the way my significant other looked at me? I can tell they're mad at me" can cause a lot of trouble in relationships.


Blaming ANTs

When things go wrong, this ANT is quick to shirk responsibility by saying, "He did it! She did it! It's not my fault! It's your fault!" This ANT doesn't want you to admit your mistakes or to learn how to fix things and make them right. It wants you to be a victim. Of all the ANTs, these are the most toxic. 

How to defeat your negative thoughts.

With practice, you can learn to eliminate the ANTs. An easy way to do so is to take notice of your thoughts and recognize any negative thoughts. Whenever you feel sad, mad, worried, nervous, or out of control, write down the negative thought, identify the ANT species, and talk back to it. Talking back to the thought takes away its power.

Challenging your negativity with rational, honest thinking is a powerful tool that can improve your brain function, boost your mood, and enhance your life.

Daniel Amen, M.D. author page.
Daniel Amen, M.D.
Clinical neuroscientist psychiatrist

Daniel Amen, MD, is a clinical neuroscientist psychiatrist, physician, professor and 10-time New York Times bestselling author. He is a double board-certified child and adult psychiatrist and founder of Amen Clinics, Inc., which has eight clinics across the country with one of the highest published success rates for treating complex psychiatric issues with the world’s largest database of functional brain scans relating to behavior, with more than 160,000 scans on patients from 121 countries. Amen is the lead researcher for the largest brain imaging and rehabilitation study for professional football players that demonstrates high levels of brain damage in players with solutions for significant recovery as a result of his extensive work. His research on post-traumatic stress disorder and traumatic brain injury was recognized by Discover magazine’s Year in Science issue as one of the “100 Top Stories of 2015.” Amen has authored and co-authored more than 70 professional articles, seven scientific book chapters and 40-plus books, including the No. 1 New York Times bestsellers, “The Daniel Plan” and “Change Your Brain, Change Your Life.” His most recent book, “Change Your Brain, Change Your Grades,” includes editorial contributions from his teenage daughter, Chloe Amen, and niece, Alizé Castellanos.