What is Trauma

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A widely used definition of Trauma (e.g., Menschner & Maul, 2016; NSW Agency for Clinical Innovation, 2019; Rajaraman et al., 2022; Ranjbar et al., 2020; Wall et al., 2016) is by Substance Abuse and Mental Health Services Administration (SAMHSA) (2014)

Individual trauma results from an event, series of events or set of circumstances that is experienced by an individual as physically or emotionally harmful or life threatening and that has lasting adverse effects on the individual’s functioning and mental, physical, social, emotional or spiritual wellbeing. (p. 7)

Trauma is the result of our ability to cope being overwhelmed by facing (or believing we face) an extreme threat or danger (Blue Knot Foundation, 2021). Events that can lead to trauma include (Blue Knot Foundation, n.d.; Menschner & Maul, 2016):

  • Physical, sexual, and emotional abuse
  • Childhood neglect
  • Violence
  • War
  • Natural disasters (e.g., floods, fires, storms)
  • Serious accidents
  • Being betrayed by a partner or close relative
  • Relationship breakdowns

Other definitions include

A stress response to an event … outside of the person’s normative life experience, and a sufficient condition that the response include a breakdown of self-regulatory functions. (Krupnik, 2019, p. 250)

An event that overwhelms the central nervous system, altering the way we process and recall memories. Trauma is not the story of something that happened back then, it’s the current imprint of that pain, horror, and fear living inside people. (Van der Kolk, 2015)

Trauma is an emotional response to a terrible event like an accident, rape, or natural disaster. Immediately after the event, shock and denial are typical. Longer term reactions include unpredictable emotions, flashbacks, strained relationships, and even physical symptoms like headaches or nausea. (American Psychological Association, n.d.)

Note that all three of these definitions talk about “an event” and, unlike SAMHSA (2014), do not specifically mention a series of events. In reality trauma can also be the results of a multiple events such as childhood abuse or domestic violence (Henderson & Everett, 2018; Herman, 1994; NSW Agency for Clinical Innovation, 2019; Thomas, 2019).

It is important to remember that trauma is not the event, but the experience of the event. As discussed below, different people can respond to the same event in different ways. Also, as Sellers (2022) suggests:

Trauma is not the event itself, but rather what happens in our bodies when we experience something overwhelming. Trauma is a response, not an event, nor is it simply an emotional response. Trauma is what happens in the body. (para. 9)

Characteristics and Types of Trauma

SAMHSA (2014) identifies “three ‘E’s’ of trauma: event(s), experience of event(s), and effect” (p. 8). Events can include the actual or extreme threat of physical or psychological harm. It can be a single event or repeated, ongoing events.

It is the individual’s experience of these events that decide whether an event is traumatic or not. Different people can experience the same event in different ways. One sibling may be deeply traumatised by childhood abuse, while another may not be. One person may find a divorce traumatic, but another may find it a relief. One person in a household may be very affected by a natural disaster, while another may not. It is the way in which an individual experiences, understands it and tries to make sense of it that lead to something being traumatic or not. It is very important to recognise that this does NOT mean we should blame the victim or tell people they should just get over it. An individual’s experience of an event can be shaped by cultural beliefs and practices (e.g., whether women are believed after domestic or sexual assault), the support they receive and how this support is delivered, their age and developmental stage, the options and choices available to them, and their previous experiences

The adverse effects of the event are a “critical component of trauma” SAMHSA (2014, p. 8). The effects can last only a short time or a lifetime. They can start immediately or be delayed. The connection between the effects and the event may be obvious or the connection between them may not be clear to the individual or those around them. (See a coming post for more discussion of potential impacts of trauma.)

Judith Herman (1994) identified two broad types of trauma: Type I Trauma, which is the result of a single incident, and Type II, which is the result of prolonged and repeated incidents (such as childhood abuse and domestic violence). Type I Trauma is sometimes called simple trauma, and Type II Trauma is sometimes called complex trauma (e.g., Fronco, 2021; McCormack & Thomson, 2017; Thomas, 2019). It should be emphasised that simple trauma is not “simple”:

It involves experiences of events that are life threatening and/or have the potential to cause serious injury. However, these incidents are not complicated by being found in relationships core to survival, by being likely to be associated with stigma, or being experienced repetitively over time. They are often single incidents. (Thomas, 2019. para. 12)

Survivors of complex trauma often feel shame and/or experience stigma even though they are not responsible for their trauma (Kezelman & Stavropoulos, 2012; McCormack & Thomson, 2017; Thomas, 2019).

Other people differentiate between Big T trauma and Little t trauma (e.g., Draper & Brown, 2022; Oglesby, 2005; Roddick).

Big “T” trauma is distinguished as an extraordinary and significant event that leaves the individual feeling powerless and possessing little control in their environment. … Little “t” traumas are events that exceed our capacity to cope and cause a disruption in emotional functioning. Often not seen as traumatic and tend to be overlooked by the individual who has experienced the difficulty. (Draper & Brown, 2022, slide 9)

Examples of Little t trauma can include interpersonal conflict, infidelity or divorce, bullying and the death of a pet (Draper & Brown, 2022; Roddick)

Other types or classifications of trauma include:

  • Intergenerational trauma which is trauma experienced by one generation is passed down to future generations (Fronco, 2021). Examples of international trauma include the trauma experienced by children of Holocaust survivors (Dashorst et al., 2019) and children of the Stolen Generation in Aboriginal and Torres Strait Islander communities (Healing Foundation, 2021, pp. 55ff).
  • Developmental trauma where the development of children (including their brain development, other physical development and/or emotional development) is adversely affect by trauma, especially Type II or complete trauma (Kraybill, 2018; Lyons et al., 2020; Thomas, 2019). See these three short videos (under 2 minutes each) about the impact of trauma on brain development.        
  • Acute, chronic and complex trauma (Allarakha, n.d.; HealthMatch, 2022). Acute trauma “mainly results from a single distressing event, such as an accident, rape, assault, or natural disaster. The event is extreme enough to threaten the person’s emotional or physical security” (Allarakha, n.d., para. 4). Chronic trauma “happens when a person is exposed to multiple, long-term, and/or prolonged distressing, traumatic events over an extended period” (para. 6). Complex trauma “is a result of exposure to varied and multiple traumatic events or experiences. The events are generally within the context of an interpersonal (between people) relationship” (para. 7).
  • Secondary trauma (also known as, or close related to, secondary traumatic stress, vicarious stress and compassion fatigue) is indirect trauma that is a result of being exposed to traumatic events indirectly (e.g., seeing it, hearing about it, or working with people who are experiencing trauma) (Watts & Robertson, 2015; White, 2022). In simple terms, secondary trauma occurs “when someone is significantly impacted by someone else’s trauma” (White, 2022, para. 5).

Posttraumatic Stress Disorder (PTSD)

The definition of Posttraumatic Stress Disorder (PTSD) in the DSM 5 (Diagnostic and Statistical Manual of Mental Disorders) is one, fairly limited (Bryant et al., 2011; Patel & Hall, 2021), approach to diagnosing trauma. While it can be a useful tool, there are other types of trauma (and even some cases of PTSD) that do not meet its specific criteria, which include:

A. Exposure to actual or threatened death, serious injury, or sexual violence in one (or more) of the following ways:

  1. Directly experiencing the traumatic event(s).
  2. Witnessing, in person, the event(s) as it occurred to others.
  3. Learning that the traumatic event(s) occurred to a close family member or close friend. In cases of actual or threatened death of a family member or friend, the event(s) must have been violent or accidental.
  4. Experiencing repeated or extreme exposure to aversive details of the traumatic event(s) (e.g., first responders collecting human remains; police officers repeatedly exposed to details of child abuse). Note: Criterion A4 does not apply to exposure through electronic media, television, movies, or pictures, unless this exposure is work related.

B. Presence of one (or more) of the following intrusion symptoms associated with the traumatic event(s), beginning after the traumatic event(s) occurred:

  1. Recurrent, involuntary, and intrusive distressing memories of the traumatic event(s). …
  2. Recurrent distressing dreams in which the content and/or affect of the dream are related to the traumatic event(s). …
  3. Dissociative reactions (e.g., flashbacks) in which the individual feels or acts as if the traumatic event(s) were recurring. …
  4. Intense or prolonged psychological distress at exposure to internal or external cues that symbolize or resemble an aspect of the traumatic event(s).
  5. Marked physiological reactions to internal or external cues that symbolize or resemble an aspect of the traumatic event(s).

C. Persistent avoidance of stimuli associated with the traumatic event(s), beginning after the traumatic event(s) occurred, as evidenced by one or both of the following. …

D. Negative alterations in cognitions and mood associated with the traumatic event(s), beginning or worsening after the traumatic event(s) occurred, as evidenced by two (or more) of the following:

  1. Inability to remember an important aspect of the traumatic event(s) (typically due to dissociative amnesia, and not to other factors such as head injury, alcohol, or drugs).
  2. Persistent and exaggerated negative beliefs or expectations about oneself, others, or the world (e.g., “I am bad,” “No one can be trusted,” “The world is completely dangerous,” “My whole nervous system is permanently ruined”).
  3. Persistent, distorted cognitions about the cause or consequences of the traumatic event(s) that lead the individual to blame himself/herself or others.
  4. Persistent negative emotional state (e.g., fear, horror, anger, guilt, or shame).
  5. Markedly diminished interest or participation in significant activities.
  6. Feelings of detachment or estrangement from others.
  7. Persistent inability to experience positive emotions (e.g., inability to experience happiness, satisfaction, or loving feelings).

E. Marked alterations in arousal and reactivity associated with the traumatic event(s), beginning or worsening after the traumatic event(s) occurred, as evidenced by two (or more) of the following:

  1. Irritable behavior and angry outbursts (with little or no provocation), typically expressed as verbal or physical aggression toward people or objects.
  2. Reckless or self-destructive behavior.
  3. Hypervigilance.
  4. Exaggerated startle response.
  5. Problems with concentration.
  6. Sleep disturbance (e.g., difficulty falling or staying asleep or restless sleep). (American Psychiatric Association, 2013, pp. 271-272)

If you liked this post please follow my blog, and you might like to look at:

  1. What are some of the impacts of trauma (coming soon)
  2. What is trauma-informed practice (coming soon)
  3. More posts in the “What is/are…?” series (Key concepts related to working with families and communities)
  4. Postcards from Practice: Initial Learnings from the Name.Narrate.Navigate Program
  5. 4 types of power: What are power over; power with; power to and power within?
  6. The Alternatives to Violence Project: Reflections on a strengths-based approach to nonviolent relationships and conflict resolution

If you find any problems with the blog, (e.g., broken links or typos) I’d love to hear about them. You can either add a comment below or contact me via the Contact page.


Allarakha, S. (n.d.). What are the 3 types of trauma? MedicineNet. Retrieved 19 February 2023, from https://www.medicinenet.com/what_are_the_3_types_of_trauma/article.htm

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders : DSM-5 (Fifth edition. ed.). American Psychiatric Association.

American Psychological Association. (n.d.) Trauma. Retrieved 19 February 2023, from https://www.apa.org/topics/trauma

Blue Knot Foundation. (2021). Having conversations about trauma – services fact sheet. https://professionals.blueknot.org.au/wp-content/uploads/2021/09/14_BK_FS_PRF_TalkingAboutTrauma_Services_JUL21.pdf

Blue Knot Foundation. (n.d.). Understanding trauma and abuse. Retrieved 8 February 2023 from https://blueknot.org.au/resources/understanding-trauma-and-abuse/

Bryant, T., Raphael, D., Schrecker, T., & Labonte, R. (2011, 6//). Canada: A land of missed opportunity for addressing the social determinants of health. Health Policy, 101(1), 44-58. https://doi.org/http://dx.doi.org/10.1016/j.healthpol.2010.08.022

Dashorst, P., Mooren, T. M., Kleber, R. J., de Jong, P. J., & Huntjens, R. J. (2019). Intergenerational consequences of the Holocaust on offspring mental health: a systematic review of associated factors and mechanisms. European journal of psychotraumatology, 10(1), 1654065. https://doi.org/10.1080/20008198.2019.1654065

Draper, C., & Brown, I. (2022). Effective treatment for trauma–skills for EA professionals [PowerPoint]. University of Maryland. http://hdl.handle.net/10713/18574

Fronco, F. (2021). Understanding intergenerational trauma. GoodTherapy. https://www.goodtherapy.org/blog/Understanding_Intergenerational_Trauma

Healing Foundation. (2021). Make healing happen: It’s time to act. Healing Foundation. https://healingfoundation.org.au/make-healing-happen/

HealthMatch. (2022, 2 September). A guide to the different types of trauma. https://healthmatch.io/ptsd/different-types-of-trauma

Henderson, C., & Everett, M. I. S. (2018). Trauma-Informed Care and Practice Organisational Toolkit (TICPOT): An organisational change process resource, Stage 2 – supporting organisational change and Stage 3 – implementation. Mental Health Coordinating Council. https://mhcc.org.au/resource/ticpot-stage-1-2-3/

Herman, J. L. (1994). Trauma and recovery. Pandora.

Kezelman, C., & Stavropoulos, P. (2012). ‘The last frontier’ –.practice guidelines for treatment of complex trauma and trauma informed care and service delivery. Adults Surviving Child Abuse. https://apo.org.au/sites/default/files/resource-files/2012-09/apo-nid31272.pdf

Kraybill, O. G. (2018). What Is Developmental Trauma? A framework for building secure attunement. Psychology Today. https://www.psychologytoday.com/au/blog/expressive-trauma-integration/201808/what-is-developmental-trauma

Krupnik, V. (2019). Trauma or Adversity? Traumatology, 25(4), 256-261. https://doi.org/10.1037/trm0000169

Lyons, S., Whyte, K., Stephens, R., & Townsend, H. (2020). Developmental trauma: Close up. Beacon House. https://beaconhouse.org.uk/wp-content/uploads/2020/02/Developmental-Trauma-Close-Up-Revised-Jan-2020.pdf

McCormack, L., & Thomson, S. (2017). Complex trauma in childhood, a psychiatric diagnosis in adulthood: Making meaning of a double-edged phenomenon. Psychological trauma: theory, research, practice, and policy, 9(2), 156.

Menschner, C., & Maul, A. (2016). Key ingredients for successful trauma-informed care implementation. Center for Health Care Strategies, Incorporated Trenton. http://www.chcs.org/media/Brief-Key-Ingredients-for-TIC-Implementation-1.pdf

NSW Agency for Clinical Innovation. (2019). Trauma-informed care and mental health in NSW. https://aci.health.nsw.gov.au/__data/assets/pdf_file/0008/561977/ACI-Trauma-informed-care-and-mental-health-in-NSW-evidence-series.pdf

Oglesby, C. A. (2005). Coping with trauma: Staying the course. In P. Markula (Ed.), Feminist sport studies: Sharing experiences ef joy and pain (pp. 101-109). State University of New York Press.

Patel, A. R., & Hall, B. J. (2021). Beyond the DSM-5 Diagnoses: A Cross-Cultural Approach to Assessing Trauma Reactions. Focus, 19(2), 197-203. https://doi.org/10.1176/appi.focus.20200049

Rajaraman, A., Austin, J. L., Gover, H. C., Cammilleri, A. P., Donnelly, D. R., & Hanley, G. P. (2022). Toward trauma‐informed applications of behavior analysis. Journal of Applied Behavior Analysis, 55(1), 40-61. https://doi.org/10.1002/jaba.881

Ranjbar, N., Erb, M., Mohammad, O., & Moreno, F. A. (2020). Trauma-informed care and cultural humility in the mental health care of people from minoritized communities. Focus, 18(1), 8-15. https://focus.psychiatryonline.org/doi/full/10.1176/appi.focus.20190027

Roddick, M. L. Big T and Little t trauma and how your body reacts to It. Good Therapy. https://www.goodtherapy.org/blog/big-t-and-little-t-trauma-and-how-your-body-reacts-to-it-1019154

Sellers, R. (2022, 11 July). Redefining Trauma. Rachel Sellers Blog. https://www.rachelesellers.com/blog/redefining-trauma

Substance Abuse and Mental Health Services Administration. (2014). SAMHSA’s concept of trauma and guidance for a traumainformed approach. https://store.samhsa.gov/product/SAMHSA-s-Concept-of-Trauma-and-Guidance-for-a-Trauma-Informed-Approach/SMA14-4884

Thomas, L. (2019, March 5). What is Trauma. Australian Childhood Foundation. https://professionals.childhood.org.au/prosody/2019/03/what-is-trauma/

Van der Kolk, B. A. (2015). The body keeps the score : brain, mind, and body in the healing of trauma. Penguin Books.

Wall, L., Higgins, D., & Hunter, C. (2016). Trauma-informed care in child/family welfare services (CFCA Paper No. 37). Australian Institute of Family Studies. https://aifs.gov.au/resources/policy-and-practice-papers/trauma-informed-care-childfamily-welfare-services

Watts, J., & Robertson, N. (2015). Selecting a measure for assessing secondary trauma in nurses. Nurse Researcher), 23(2), 30-35. https://doi.org/10.7748/nr.23.2.30.s7

White, T. (2022). What Is Secondary Trauma? PsychCentral. https://psychcentral.com/health/secondary-trauma

About Graeme Stuart

Lecturer (Family Action Centre, Newcastle Uni), blogger (Sustaining Community), Alternatives to Violence Project facilitator, environmentalist, father. Passionate about families, community development, peace, sustainability.
This entry was posted in Families & parenting and tagged , , , . Bookmark the permalink.

2 Responses to What is Trauma

  1. Anaru August says:

    Hi there, have you done many articles on trauma-informed approaches to practice?
    I’m interested in trauma-informed organizations and the impact on practitioners and people they work with i.e. patients or participants if an organization has a systemic culture that is trauma-inducing.


    • Hi Anaru, No I haven’t done many specifically about trauma, but I’m about to do a couple more over the coming weeks. I started out planning a post about what is trauma informed practice, but decided to do some background first.


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