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

by Sally M. Winston PsyD

The Alarm Response To understand how unwanted intrusive thoughts work, we start with the alarm response that is built into everyone’s brain. This response is sometimes called the stress response, the fight-or-flight response, or—most accurately—the fight, flight, or freeze response. It sets up your body to go through a whole series of arousals—all of which are helpful when you are in danger. These responses include release of adrenaline, increased heart rate, changes in breathing, hypervigilance to possible danger, tunnel vision, and a host of other perceptual changes. You feel this as a whoosh of fear or terror. The alarm response is centered in the amygdala, which consists of two walnut-sized structures in your brain. The amygdala can be either on or off: it either triggers the alarm response or it doesn’t. The alarm response is wordless—think of it like a clanging danger-warning bell. There are no partial responses or other subtleties. Because it is designed to alert you to danger, your amygdala is triggered by just the merest hint of a possible danger. Its job is to protect you—not to keep you comfortable—so it would rather set off a thousand false alarms and create a thousand whooshes of fear when there is no problem at all than miss one that is real. It was originally designed for primitive survival. Clanging the alarm when there is no danger is called a false positive. Remaining silent when there is a real danger is a false negative. Your amygdala sends out many, ma...