You’ve probably heard the old saying, “Don’t believe everything you think.”

That might be some of the best mental health advice ever given.

Unhappy people tend to let their thoughts run wild. They rehearse hurts, replay regrets, and catastrophize about the future. Happy people do something different — they think about what they think about.

Dr. David Burns, a psychiatrist at Stanford University, discovered something revolutionary while working with patients suffering from depression. He noticed that their moods weren’t caused by events themselves, but by their interpretation of those events. Change the thought, and the emotion changes too. 

Jean Greaves and Travis Bradberry put it this way:

Since our brains are wired to make us emotional creatures, your first reaction to an event is always going to be an emotional one. You have no control over this part of the process. You do control the thoughts that follow an emotion, and you have a great deal of say in how you react to an emotion—as long as you are aware of it.[1]

That insight became the foundation of Cognitive Behavioral Therapy (CBT) — a simple yet profound approach that’s transformed millions of lives.

At first, people doubted it could work. Could talking back to your thoughts really make a difference compared to antidepressants? But study after study proved that it could — and often better.

Researchers at the University of Pennsylvania compared two groups of people with clinical depression. One group received antidepressants; the other received CBT. Both improved — but when treatment stopped, the medication group relapsed at twice the rate of the CBT group. Later studies at Harvard and King’s College London confirmed the same: CBT often works as well as medication for moderate to severe depression, and its effects last longer because it changes the mental habits that cause unhappiness in the first place.

Medication can reset brain chemistry. But CBT reshapes the brain itself. MRI scans show that it strengthens the prefrontal cortex — the part that regulates mood and reason — while calming the overactive amygdala, which triggers anxiety and fear.

In short: antidepressants can calm the storm, but CBT teaches you how to sail the ship.

And that’s exactly what happy people do, whether they know it or not. They’ve learned the habit of thinking about what they think about.

Here some highlights from Burns’s book Feeling Good:

In contrast, you can learn to change the way you think about things, and you can also change your basic values and beliefs. And when you do, you will often experience profound and lasting changes in your mood, outlook, and productivity. That, in a nutshell, is what cognitive therapy is all about.

Drugs are the most common treatment for depression in the United States, and there is a widespread belief, popularized by the media, that drugs are the most effective treatment. However, this opinion is not consistent with the results of many carefully conducted outcome studies during the past twenty years. These studies show that the newer forms of psychotherapy, especially cognitive therapy, can be at least as effective as drugs, and for many patients appear to be more effective.

Recent studies indicate that psychotherapy can be helpful not only for mild depressions, but also for severe depressions as well.               

The first principle of cognitive therapy is that all your moods are created by your “cognitions,” or thoughts. A cognition refers to the way you look at things—your perceptions, mental attitudes, and beliefs. It includes the way you interpret things—what you say about something or someone to yourself. You feel the way you do right now because of the thoughts you are thinking at this moment. Let me illustrate this. How have you been feeling as you read this? You might have been thinking, “Cognitive therapy sounds too good to be true. It would never work for me.” If your thoughts run along these lines, you are feeling skeptical or even discouraged. What causes you to feel that way? Your thoughts. You create those feelings by the dialogue you are having with yourself about this book! Conversely, you may have felt a sudden uplift in mood because you thought, “Hey, this sounds like something which might finally help me.” Your emotional reaction is generated not by the sentences you are reading but by the way you are thinking. The moment you have a certain thought and believe it, you will experience an immediate emotional response. Your thought actually creates the emotion.               

The second principle is that when you are feeling depressed, your thoughts are dominated by a pervasive negativity. You perceive not only yourself but the entire world in dark, gloomy terms. What is even worse—you’ll come to believe things really are as bad as you imagine them to be. If you are substantially depressed, you will even begin to believe that things always have been and always will be negative. As you look into your past, you remember all the bad things that have happened to you. As you try to imagine the future, you see only emptiness or unending problems and anguish. This bleak vision creates a sense of hopelessness. This feeling is absolutely illogical, but it seems so real that you have convinced yourself that your inadequacy will go on forever.               

The third principle is of substantial philosophical and therapeutic importance. Our research has documented that the negative thoughts which cause your emotional turmoil nearly always contain gross distortions. Although these thoughts appear valid, you will learn that they are irrational or just plain wrong, and that twisted thinking is a major cause of your suffering. The implications are important. Your depression is probably not based on accurate perceptions of reality but is often the product of mental slippage.