We now know from recent research that getting stuck on negative thoughts, itself, can actually result in physical damage to the brain. Becoming abnormally consumed with negative thoughts, feelings and actions, continually turning a situation over and over in the mind, focusing only on its negative aspects, or “ruminating,” can actually damage the neural structures in the brain that regulate feelings, emotions and memory, according to Andrew Newberg, M.D, a pioneer in the field of neurotheology.

Newberg and co-author Mark Waldman write about fascinating new research that reveals the effect that just seeing or hearing negative words can have on the brain.

Newberg explains that if you were put into an MRI scanner (a device that takes a video of your brain), and the word “NO” was flashed in front of you for less than even a second, the picture your brain would produce would show “a sudden release of dozens of stress—producing hormones and neurotransmitters,“ chemicals that would “immediately interrupt the normal functioning of your brain, impairing logic, reason, language processing, and communication.”

Seeing a list of negative words for just a few seconds, says Newberg, can have an even greater impact. They have the power to make an anxious or depressed person feel worse, and the more you focus on them the more disruptive these words can be, even to the point of disrupting your life  affecting sleep, appetite, and your ability to experience long-term joy and satisfaction.

Vocalizing, on top of seeing the word, “No,” adds Newberg, increases the effects on your brain even more, and not just your brain, but the listener’s brain as well. Thus parents, teachers and other authority figures can have a profound effect upon children just by the way they teach them to behave or learn. Most important, says Newberg, “if you teach them to think positive, you can turn their lives around.”

Further research on the effects of negative thinking on the brain is even more revealing. As noted earlier, there is now scientific understanding that humans have evolved to focus on the negative as a mechanism necessary for survival. We learned our first years on earth how to respond quickly to real safety threats. However now, when we worry or have negative thoughts over issues that are not life—threatening, our brains don’t know the difference and are tricked into thinking there is an immediate threat, which leads to stress and the fight or flight response.

On the other hand, if we train ourselves to think more positively about the challenges we face, then our brain assumes the situation is safe and under control, and it doesn’t create the stressful reaction that leads to other negative results.

More specifically, it’s the thalamus in our brains that gets confused when we send negative messages. It doesn’t realize that the thoughts are not the same as real danger, so it reacts by sending motor and sensory signals to the rest of the body preparing it to flee. This puts us in a state of arousal which causes us to sweat and breathe harder. That increases our heartbeat and raises our blood pressure and puts us in a state of stress.

Chronic stress can have badly affects our health, our looks and our happiness. If we allow the negative thinking to go on uninterrupted, the stress it creates can change the brain enough to cause numerous mental or emotional disorders, some as serious as ADHD or what are considered serious mental conditions.

From: Negative Thoughts Don’t Have to Own You, by Vivian Orgel