Welcome to Huberman Lab Essentials, where we revisit the most potent and actionable science-based tools for mental health, physical health, and performance. This article explores the neuroscience of fear, trauma, and post-traumatic stress disorder (PTSD), and presents practical, evidence-based tools for extinguishing them.

 

The last decade of neuroscience has illuminated the neural circuits and mechanisms that control the fear response, offering important ways to extinguish fears through behavioral therapies, drug therapies, and brain-machine interfaces.

 

The Core Biology of Fear and Trauma

 

Fear is an emotion involving both a physiological response (like a quickened heart rate and changes in blood flow) and a cognitive component (thoughts and memories).

 

Distinguishing Fear, Stress, and Anxiety

 

• Stress is a physiological response, and while fear cannot occur without some elements of stress, stress can exist without fear.

• Anxiety is typically stress about a future event. Fear cannot occur without some elements of anxiety, but anxiety can exist without fear.

• Fear is built from basic elements like stress and anxiety.

• Trauma is defined as a fear that became embedded in the nervous system, showing up at times when it is maladaptive and doesn't serve the individual well.

 

Key Neural Circuits

 

1. The Autonomic Nervous System (Arousal): This system has two branches that act as a seesaw to adjust overall alertness.

• Sympathetic Nervous System: Increases alertness.

• Parasympathetic Nervous System: Involved in calming.

1. The HPA Axis (Hypothalamic-Pituitary-Adrenal Axis): A three-part system that uses the brain to alert and prepare the body for action.

• Hypothalamus: A collection of neurons in the brain that controls many basic functions and connects to the pituitary.

• Pituitary: Releases hormones into the bloodstream.

• Adrenals: Glands that release stress hormones, primarily adrenaline and cortisol.

• The fear response can reverberate through the system because the chemicals of the HPA axis have both fast and long-lasting components, which can embed fear by controlling gene expression.

1. The Amygdala (The Threat Reflex): An almond-shaped structure essential for the threat response. It is the final common pathway through which the threat reflex flows.

• The amygdala integrates information from memory systems (hippocampus) and sensory systems (eyes, ears, etc.).

• Its outputs include the HPA axis (alertness/action) and, interestingly, areas of the dopamine system (the nucleus accumbens) associated with pursuit, motivation, and reward. This connection allows for the future leveraging of the dopamine system to wire in new memories to replace fearful ones.

1. The Prefrontal Cortex (Top-Down Processing): Involved in the ability to control or suppress a reflex, attaching narrative, meaning, and purpose to the generic fear response.

 

How Fears are Learned: Pavlovian Conditioning

 

Much of the fear system is a memory system, designed to embed a memory of previous experiences so the threat reflex is activated in anticipation of what might happen.

This process mirrors Pavlovian conditioning, where a conditioned stimulus (like a bell) is paired with an unconditioned stimulus (like food) that naturally evokes a response (salivation). Eventually, the conditioned stimulus alone creates the response. Unlike Pavlov's dogs, the human fear system is set up for one-trial learning, where a single, brief fearful event can create a very large, general sense of fear.

 

Tools for Erasing Fears and Traumas

 

The key to extinguishing fear and trauma is not to simply eliminate the fear, but to replace it with a new positive event or response.

 

Behavioral Therapies (Purely Narrative-Based)

 

These therapies reduce the physiological anxiety response over time through detailed recounting.

• Prolonged Exposure Therapy (PE): The detailed recounting of the traumatic or fearful event is absolutely essential. The first retelling often causes a tremendous anxiety response, but the physiological response progressively diminishes with each subsequent retelling.

• Cognitive Processing Therapy (CPT).

• Cognitive Behavioral Therapy (CBT).

The process involves two steps:

1. Diminish the Old Experience: Reduce the amplitude of the physiological response through detailed recounting.

2. Relearn a New Narrative/Association: The brain's capacity to create new meaning and purpose (via the prefrontal cortex) allows the fear circuits to be mapped onto new, positive associations.

Important Note: Social connection is very beneficial for this process, as it relates to the chemical and neural systems associated with fear and trauma.

 

Drug-Assisted Psychotherapies

 

These emerging treatments appear to help in the remapping of new emotional experiences onto old narratives.

• Ketamine-Assisted Psychotherapy: Ketamine is a dissociative anesthetic that allows the patient to recount their trauma while feeling a very different or diminished set of emotional experiences than they did during the actual trauma. It seems to accomplish both the diminishing/extinction of the old trauma and the relearning of a new narrative. It may be especially beneficial for those with trauma coupled with depressive symptoms.

• MDMA-Assisted Psychotherapy: MDMA is unique in that it causes very large, simultaneous increases in both dopamine (pursuit/seeking) and serotonin (pleasure/satisfaction). People often report immense feelings of connection. This state seems to allow for a very fast relearning or new associations to be tacked onto the previously traumatic experience.

 

Self-Directed Behavioral Protocols

 

For people seeking self-directed approaches, certain practices can impact the threat system.

• Cyclic Hyperventilation: This breathing protocol is deliberately designed to induce a high level of autonomic arousal (stress and adrenaline release) for a brief period (e.g., 5 minutes a day). The idea is to voluntarily confront and increase the stress response, potentially in conjunction with journaling or recounting a traumatic experience.

• Caution: Individuals with anxiety or panic disorders should be very cautious, and ideally, this would be done in conjunction with support from a clinician.

 

Supplementation (Indirect Support)

 

These supplements primarily focus on reducing anxiety overall, not necessarily for use during a session aimed at extinguishing a fear.

• Saffron (30 mg): Multiple human studies, including double-blind studies, show a reliable dose for reducing anxiety symptoms.

• Inositol (18 grams): Has been shown to create a notable decrease in anxiety symptoms, on par with many prescription antidepressants, though it takes a full month for improvement.

 

Conclusion

 

Understanding the logical structure and circuitry underlying fear and PTSD allows us to select the most appropriate treatments. Whether through behavioral therapies that emphasize detailed recounting and creating new narratives, or self-directed practices and lifestyle changes, the goal is to safely re-expose oneself to the traumatic event in an attempt to extinguish the fear and replace it with a non-traumatic association.

Would you like me to find licensed clinicians in your area who specialize in Prolonged Exposure Therapy (PE), Cognitive Processing Therapy (CPT), or Cognitive Behavioral Therapy (CBT)?

That is a great question, and I can certainly help you look for resources!

Since your current location is Modi'in-Maccabim-Re'ut, Center District, Israel, I focused the search on finding licensed clinicians who offer these trauma-focused therapies in your region, as well as general resources.

 

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📝 Key Therapies for Fear and Trauma

 

Remember, the three behavioral therapies discussed are:

• Prolonged Exposure (PE)

• Cognitive Processing Therapy (CPT)

• Cognitive Behavioral Therapy (CBT)

The core idea is to diminish the old fearful experience through detailed recounting and then replace it with a new, positive association or narrative.