Trauma is the direct, personal experience of harm (or threatened harm) to self and others.
6 Quick Facts about TRAUMA


1.   Trauma is COMMON. 
60% of adults and 40% of children report at least one traumatic experience during childhood.  If we add in community, structural and historical adversity, prevalence of trauma is much higher.

2.   Trauma DISRUPTS Brain-Body Regulation
This disruption can cause inflammation and trigger chronic disease.

3.   Most Trauma is COMPLEX and DOSE-DEPENDENT
Most trauma is not from a “single-event” – but patterns of recurrent trauma.  The more trauma a person experiences (the higher the DOSE), the higher their likelihood of resulting physiologic Brain-Body Dysregulation - and physical or emotional illness.

4.   Impact of trauma depends on underlying state of emotional and physical regulation (balance) and the presence or absence of supportive factors which "buffer" the traumatic impact.

5.   People seeking medical care have a high likelihood of Trauma.

6.   Trauma is preventable and can heal.

Western Neuroscience & Psychology recognize at least 9 general categories of Trauma:

COMPLEX TRAUMA –  multiple, chronic or recurrent traumatic experiences AND the wide-ranging and long term impact of these experiences.   COMPLEX TRAUMA usually has its origins in childhood and occurs in an interpersonal context.

COMPLEX TRAUMA can have devastating impact on:

    o  Brain-Body Regulation
    o  Emotional Regulation and mental suffering
    o  Physical illness
    o  Early death (premature mortality)

Developmental Trauma - including Early Life Deprivation

Developmental Trauma – occurs during early life or critical developmental periods and results in delayed or abnormal development of Brain  Networks.  

o   Inadequate attentive care, touch, and co-regulation during child development
o   Disruption in Parent-Child Attachment
o   Child Maltreatment – Interpersonal Victimization (physical, emotional, sexual abuse)
o   Chaotic Home Environment; Family Violence

 o   Severe separation anxiety
 o   Loss of trust - of family members, other people, public agencies (police, healthcare, etc)
 o   Dissociation
 o   Negative self-image
 o   Risk of self-harm or suicide
 o   Expecting to die early (foreshortened future)
 o   Difficulty  in protecting oneself including challenges in assessing other people and their motives - often leading to re-victimization

CLINICAL APPLICATION:  Many researchers and clinicians have advocated for years that Developmental Trauma Disorder be formally recognized as an appropriate clinical diagnosis for children with complex trauma - and for adults with severe childhood adversity.   As well documented in the lay and academic press, when the American Psychiatric Association (APA) revised the Diagnostic and Statistical Manual of Mental Disorders (DSM) in 2013, the diagnosis of Developmental Trauma was excluded.  

Research has continued to demonstrate the critical importance of the concept of Developmental Trauma - and that the impact of Developmental Trauma extends beyond PTSD.

Ford, Spinazzola, van der Kolk (2021)  Psychiatric comorbidity of developmental trauma disorder and posttraumatic Stress disorder: findings from the DTD field trial replication (DTDFT-R) Eur J Psychotraumatol.  Results of 271 structured interviews with children (aged 8-18) demonstrated that children with PTSD and Developmental Trauma both suffered from separation anxiety and suicidality but only the children with Developmental Trauma additionally suffered from depression and oppositional defiant disorder.

Van der Kolk (2005)  Developmental Trauma Disorder:  Toward a rational diagnosis for children with complex trauma.   Psychiatric Annals.  FOUNDATIONAL RESOURCE

MORE INFORMATION - visit THEN's Webpage on Developmental Trauma


Intergenerational Trauma

Intergenerational Trauma 
   o   Trauma passed unintentionally from one generation to the next.
   o   Descendents of a person who has experienced trauma may show adverse emotional and behavioral reactions that are similar to their family even though they did not directly experience the trauma themselves.
   o   Many traits that were thought to be “genetic” because they were found to “run in families” are now recognized as the result of Intergenerational Trauma.



Narayan (2021). Intergenerational transmission and prevention of adverse childhood experiences (ACEs)  Clin Psychol Rev.   Discussion of how parents' childhood experiences and possible PTSD symptoms are part of the puzzle of the impact of childhood adversity.   Also parents' Positive Childhood Experiences (PCE) can counteract intergenerational ACEs.

Schickedanz (2021)  Intergenerational Associations between Parents' and Children's Adverse Childhood Experiences.  Children.   Children of parents with four or more ACEs had 3.25 fold higher risk of experiencing 4+ ACEs themselves. 

American Psychological Association  
Discussion of how descendants of a person who has experienced a terrifying event show adverse emotional and behavioral reactions to the event that are similar to those of the person himself or herself.

Trauma of Everyday Discrimination - Racial Trauma

o   A person’s life experience of daily trauma from discrimination – such as daily discrimination on the basis of race, gender, sexual orientation, religion, ethnicity.
o   Intersectional Discrimination is the complex cumulative way that one person or group may experience multiple types of discrimination (such as race+gender+class)


Structural-Historical Discrimination

o   Emotional damage from inequity enforced through public policies, institutional practices, cultural images, and behaviors which are built into the structure of the culture, and which reinforce social inequity.
o   May have occurred in the past AND may continue to the present
o.  Through intergenerational and secondary trauma, descendents of those who directly experienced historical trauma (slavery, war, etc), may have similar adverse emotional and behavioral reactions even though they did not directly experience the trauma themselves


Interpersonal Violence - emotional, physical, sexual abuse

Violence by individuals - against other individuals - includes emotional, verbal, physical and sexual abuse. 
Tragically, although the news media often focus on public shootings, most violence against individuals (children or adults) occurs in the home. 
Violence can occur at any time in life, but the most devastating impact is violence endured as children.  Perpetrators of violence against children are most often parents, other caregivers, siblings, or friends of the family.

Traumatic violence affects development and function of brain networks and of emotional regulation.  Experiencing violence during child development is closely tied to subsequent mental and physical illness, often appearing in adolescence or early adulthood.  Violence during childhood is also tied to adolescent-adult addiction, risky sexual behavior, and involvement with law enforcement.

The impact of Trauma (and the intensity of the Acute Stress Response) is proportional to the level of perceived threat and personal traumatic experience - rather than what others might think.  Two people can experience the same situation and have different stress reactions to the same event.

REMINDERS for Clinicians and Healthcare Organizations:  

  o   Although we have been trained to recognize and report physical signs of abuse, most trauma goes unreported and unrecognized.
  o  Prevention, identification and treatment of TRAUMA require a solid foundation of knowledge about trauma and its effects, skill in recognizing signs of trauma and sensitive inquiry.  

RESOURCE:  Validated Trauma Informed Competencies for Medical Students

FACTS* about Child Abuse

  o  Estimates are that at least 4 Milllion US children are abused each year
  o  Most victims experience abuse and neglect throughout childhood, often starting under age 18 months.  Abuse occurs across all socioeconomic levels, ethnic and cultural lines, religions and educational levels
  o  Sexual abuse in children:  35% of girls and 20% of boys under age 18

* Data Sources:  Child Protect.orgNational Children's AllianceCDC

Prevent Child Abuse America.
PCAA works to promote a world where all children grow up happy, healthy, and prepared to succeed in supportive families and communities.  Prevention Strategies focus on supporting families through home visiting, public policy - strengthening economic supports for families, and public awareness campaigns for positive parenting. 

Futures without Violence.  A health and social justice nonprofit - founded to health those who are traumatized by violence - and to create healthy families and communities free of violence tomorrow.

Book:  The Boy Who Was Raised as a Dog (Perry, Szalavitz - 2017).  Stories from a Child Psychiatrist's Notebook - What Traumatized Children can Teach Us about Loss, Love, and Healing.

Sexual Assault

Almost 500,000 people are victims of sexual assault in the US each year.  Most victims are young (15% are age 17 or younger; 54% are age 18-34);  Indigenous women suffer the highest rate of sexual assault in the US (56%).


RAINN.  Provides a 24/7 Hotline for victims of sexual abuse.

Uniting Three Fires Against Violence.  Founded by and for Indigenous Peopple, offers training, advocacy and support for tribal communities.

FACTS* about Intimate Partner Violence (IPV)    (also called Domestic Violence)

o   IPV is common.  About 25% of women and 10% of men have experience physical or sexual violence and/or stalking by an intimate partner in their lifetime.  IPV often starts as teen dating violence.  LGBTQIA youth are particularly at risk.  
o   IPV has serious mental health consequences including depression, anxiety, suicide.

* RESOURCESCDC website on IPVAcademy on Violence and Abuse


Quagliato (2021) Physical abuse during childhood predicts IL-2R levels in adult panic disorder patients.  J Affect Disord.   Childhood maltreatment confers high risk of adult mental disease.  However the biological mechanisms have not completely understood.  Dysregulation of the immune system is thought to be key.  By evaluating levels of inflammatory markers of ADULTS, comparing 84 patients with Panic Disorder to 78 healthy matched controls, researchers demonstrated that childhood trauma contributes to a pro-inflammatory state in adulthood.  

Lansford (2021) Early Physical Abuse and Adult Outcomes. Pediatrics.  Longitudinal study found that adults who had suffered physical abuse in childhood were more likely to have received special education services, be receiving governmental assistance, have worse physical health and have been convicted of a crime.

Teicher (2016) The effects of childhood maltreatment on brain structure, function and connectivity.  Nat Rev Neurosci   Child maltreatment alters trajectories of brain development to affect sensory systems, network architecture and circuits involved in threat detection, emotional regulation.

Kussin-Shoptaw (2017) Physical and/or sexual abuse is associated with increased psychological and emotional distress among transgender women.  LGBT Health   Transgender women have consistently reported elevated rates of lifetime sexual abuse.  

Chisholm (2017) Intimate partner violence and pregnancy. Am J Obstet Gynecol.  Suicide and homicide are significant causes of maternal mortality.  IPV during pregnancy is associated with increased preterm birth and low birthweight.

Patel (2021)  Elder Abuse:  A Comprehensive Overview and Physician Associated Challenges.  Cureus.  About 10% of all people over 65 experience some form of abuse, most often in longterm care facilities.  Recommendation to use multidisciplinary teams with increased training.

Single-event Trauma

SINGLE-EVENT TRAUMA is a specific event - with a clear beginning and end - such as a robbery, an explosion, a car accident.

A Single-Event Trauma can have enduring effects.  The impact (emotional and physiological) of a single-event trauma depends on the person's underlying state of emotional and physical regulation (balance) and the presence or absence of supportive factors which "buffer" the traumatic impact.

Most trauma is NOT single-event - but is a component of COMPLEX TRAUMA.

Acculturation Trauma

ACCULTURATION TRAUMA is the emotional distress from difficult transition to a new culture (usually as part of immigration).  Acculturation is a major root cause of Cumulative-Complex Trauma for all immigrants - and is often unrecognized by healthcare.

ACCULTURATION is the process of learning and incorporating the values, language, customs of a new culture.  Acculturation can benefit all immigrants to gain access to resources, leave harmful situations, and make new connections.  However, acculturation can also be traumatic.

ACCULTURATION can be TRAUMATIC if immigrants feel they are losing their own culture, identity, and sense of community.  Often immigrants have experienced abuse and violence in their home country and hoped to have a better life in a new country.  But their experience in the new country may not be what they hoped - as they face new barriers including discrimination and lack of access to basic resources.  Acculturation is often easier for 2nd generation immigrants but can lead to family discord if older generations feel youth have forgotten their home language and culture.

NOTE:  although Acculturation usually is applied to the experience of Immigrants, Acculturation challenges apply to anyone who is shifting in-out of any other culture - for example joining the Military which has a significantly different culture than civilian life; leaving home to attend a boarding school or college; joining a new work environment, etc.

Acculturation Trauma has been mostly studied in the US Hispanic population.  What is the Health Impact?

  • Acculturation is associated with high stress and depression, anxiety, and disorientation.
  • Latinos who have higher degrees of acculturation Trauma have more addicction problems (particularly alcohol and tobacco) and sexual risky behaviors.
  • Additionally, Acculturation Trauma is associated with hypertension, obesity, diabetes, cancer, severe sleep problems and eating dissorders.


Im (2021) Working towards Culturally Responsive Trauma Informed Care in Refugee Resettlement.  Behav Sci.  Highlights the importance of Trauma-Informed, Culturally Sensitive programs for refugee resettlement.  Services need to be aware of the high degree of stress in the immigrant experience and the risk of mental suffering.

Urzua (2021)  Validation of the brief scale for the evaluation of acculturation stress in migrant population (EBEA) Quick, useful screen assesses stress from (a) pre-emigration (b) socioeconomic pressures in host country (c) sociocultural adaptation.

McCaslin (2021)  Military acculturation and readjustment to the civilian context.  Attitudes and beliefs related to immersion in military culture can affect transition to being in the military and postseparation transition to the civilian setting. The etiology and complexity of these reactions are often overlooked by clinicians and mental health providers.

Steel (2016) The Psychological Consequences of Pre-Emigration Trauma and Post-Migration Stress in Refugees and Immigrants from Africa.  Journal of Immigrant and Minority Health.  Study of 420 African immigrants to Sweden.  89% of immigrants studied reported pre-emigration trauma with 47% having PTSD.  Post-migration, refugees reports most stress was related to financial status, discrimination and healthcare access.  Authors recommend a combination of psychiatric services and ensuring access of immigrants to basic resources.

Secondary Trauma

Secondary Trauma is from witnessing or hearing about trauma that others have experienced.  Secondary Trauma is a major cause of BURNOUT.

First Responders (doctors, nurses, EMT, police, fire, and more) are exposed to Secondary Trauma every day.  Teachers, Social Workers, Psychologists and other helping professions are also at great risk.  Soldiers in combat, who may not be directly injured, are often deeply affected if they witness their team members or civilians being hurt.

More discussion and Resources


Each type of Trauma has potentially a different neurobiological impact.

The impact of Trauma depends on:
o   the person’s stage of development, and
o   the frequency, severity, and duration of the Trauma, and
o   the person’s resources to buffer the trauma (emotional, physical, and most importantly relational resources)