How Can You Tell The Difference Between Normal Trauma Response And Post-Traumatic Stress Disorder?

Trauma is, the American Psychological Association explains, an "emotional response to a terrible event like an accident, rape or natural disaster". Though not everyone will consider the same events traumatic, you'd pretty much have to be an inanimate object to not be psychologically affected by adverse experiences that put your life in danger, during which people were killed, in which you or others were injured, or in which there was sexual violence — like war, a house fire, domestic violence, or even serious medical emergencies. 

How can you tell the difference between a normative trauma response (sometimes called simply "post-traumatic stress", without the "disorder" part) and full-blown PTSD?

What might a normative response to a trauma look like?

Research shows that three quarters of people who experience a trauma have PTSD-like symptoms in the immediate aftermath, but almost everyone will experience some kind of stress reaction — often after initially feeling relieved at just being alive. 

The emotional and mental experiences common after living through a trauma include being in shock and not quite believing the event actually happened, feeling detached, and being scared, feeling hopeless, and feeling angry or irritated. You may avoid the world around you, especially things that remind you of the trauma, and feel unable to concentrate or function normally. It's also pretty normal to be quick to startle, to think about the traumatic event a lot, and to find it hard to shake the feeling that more bad things are about to happen. 

The physical reactions people often have after a trauma include trouble sleeping, heart palpitations, excessive sweating, and headaches. You may also neglect self-care — not eating well or exercising, and engaging in unhealthy behaviors like smoking and drinking. 

What makes PTSD different from normative trauma responses (or post-traumatic stress)

All of these normative trauma responses are also seen in people who are diagnosed with post-traumatic stress disorder. So, what is the difference? Around 75 percent of people who initially experience psychological and physical resposes after trauma recover on their own, processing what happened and finding a way to carry on with life or build a new life. 

The diagnostic and statistical manual of mental disorders (DSM-5), used to diagnose PTSD in the US, has the following other diagnostic criteria: 

• At least one intrusion symptom. You may suffer from involuntary and intrusive memories of the trauma, be plagued by the event in your nightmares, or experience flashbacks when triggered by a reminder, such as a smell, person, place, or feeling.
• At least one avoidance symptom. Avoiding reminders of the trauma comes in two possible forms. You may fight reminders that emerge from your own mind — thoughts, feelings, or memories — as well as external reminders like people, places, or events connected to the trauma. 
• At least two negative changes in your mood and thought patterns. These changes can come in numerous forms — maybe you can't remember important parts of the trauma, have unrealistically negative thoughts about yourself, others, or the world at large (can't trust anyone or think you're a bad person), or are chronically plagued by self-blame or blaming others. Perhaos your dominant emotions are difficult ones like fear, horror, anger, or shame, you've lost interest in previously important activities, feel detached or alienated from others, or can't seem to feel positive emotions anymore.
• At least two hyperarousal symptoms. These would include always being on guard, an oversensitive startle response, trouble concentrating, dysfunctional sleep, irritable and angry outbursts, and also reckless of self-destructive behavior. 

Why do some people develop PTSD after a trauma, while others don't?

Developing PTSD doesn't mean you're in any way "defective". Rather, research has found, people who don't develop PTSD tend to not have experienced trauma before and are likely to have higher levels of social support. People who do end up with post-traumatic stress disorder will often already have experienced a cascade of traumatic, adverse, or victimizing events earlier in life. As one builds on the other, the natural ability to "fight it off" wanes, and PTSD often results. Social isolation is an important predictor of PTSD, too, as is the severity of the trauma.