“deep brain trauma” – trauma that affects the brain and nervous system at a profound level, it is important to distinguish brain injury from psychological trauma. They can overlap, but they are not the same thing.

This occurs when an experience overwhelms a person’s ability to cope and creates a lasting sense of threat.

Examples include:

The trauma can affect emotional regulation, memory, attention, sleep, relationships, and the nervous system.

What people sometimes call deep trauma isn’t usually a formal diagnostic category. It generally refers to trauma that is chronic, repeated, interpersonal, or occurring during critical developmental periods.

Examples include prolonged childhood abuse, captivity, trafficking, or years of domestic violence.

Because the threat is repeated, the person may adapt by becoming chronically hypervigilant, emotionally numb, dissociative, or highly attuned to other people’s moods.

This is sometimes discussed in relation to complex PTSD, although terminology and diagnostic criteria vary by diagnostic system.

This is fundamentally different.

A TBI involves physical injury to the brain, such as from:

A TBI can affect memory, concentration, impulse control, mood, personality, balance, and other neurological functions.

Trauma occurring during childhood can have particularly broad effects because the brain and emotional-regulation systems are still developing.

Repeated childhood adversity can influence how a person learns:

These beliefs can subsequently influence attachment, relationships, emotional regulation, and coping.

This occurs within important relationships—particularly when the person who is supposed to provide safety is also the source of danger.

That can make domestic violence, coercive control, betrayal, and childhood abuse especially psychologically complicated.

The person may simultaneously experience:

That combination can contribute to trauma bonding and make separation psychologically difficult.

An overwhelming experience that changes how the person perceives safety, relationships, emotions, and themselves.

A physical injury to brain tissue/function.

Usually refers to the cumulative effects of prolonged or repeated trauma, particularly interpersonal or developmental trauma—not a separate anatomical layer of the brain.

And there is an important connection: psychological trauma can produce measurable changes in brain and nervous-system functioning without causing a traumatic brain injury.

So rather than thinking of trauma as simply being “in the mind,” a better model is:

That is why profound trauma can continue affecting a person long after the danger itself has ended.