Overcoming Unwanted Intrusive Thoughts: A CBT-Based Guide to Getting Over Frightening, Obsessive, or Disturbing Thoughts

by Sally M. Winston PsyD

When we are startled or surprised, or when something happens that tricks us into thinking there is danger, the alarm system part of our brain called the amygdala sends out a danger signal. It instantly makes many things happen in the body that enable us to run away or fight if there were a real danger. You may know this reaction as the fight-or-flight response. This happens automatically, whether the alarm is false or indicates a true danger. The amygdala is not very smart and cannot judge true danger from a false alarm. It just responds to a trigger—real or imagined—with the only thing it can do. It sends out an alarm. If we are startled by a thought and our amygdala automatically sends out such a danger signal, then we react emotionally as if there is danger. The sensations in our body make the thought seem dangerous, impulsive, or important. We discuss this further in chapter 5. But our brain has a second mechanism located in the higher brain or cortex that has the capacity to say, “Wait a minute—this is just a thought.” The cortex is where we think, reason, and judge. The problem is that the message from the higher brain gets there about a half of a second after the first automatic alarm has sounded. So you are feeling like you are in danger, even before your higher brain has the chance to step in.