The DSM-5 diagnoses PTSD using eight criteria, labeled A through H, that together establish whether a person’s symptoms meet the threshold for the disorder. A diagnosis requires exposure to a qualifying traumatic event, a minimum number of symptoms across four distinct clusters, symptoms lasting more than one month, meaningful impairment in daily life, and confirmation that the symptoms aren’t caused by substances or another medical condition.
Criterion A: The Traumatic Event
Not every distressing experience qualifies. The DSM-5 requires exposure to actual or threatened death, serious injury, or sexual violence. That exposure can happen in one of four ways: experiencing the event directly, witnessing it happen to someone else, learning that it happened to a close family member or friend, or being repeatedly exposed to disturbing details of traumatic events through your work (first responders reviewing evidence of child abuse, for example). That last route specifically excludes exposure through media, television, or images unless it’s work-related.
This criterion is the gateway to the entire diagnosis. If the event doesn’t involve death, serious injury, or sexual violence in one of those four forms, PTSD technically cannot be diagnosed under the DSM-5, even if the person is severely distressed.
Criterion B: Re-Experiencing Symptoms
At least one of the following five symptoms must be present. The traumatic event keeps intruding into your present life in ways you can’t control:
- Unwanted upsetting memories of the event that surface repeatedly without being invited
- Nightmares related to the trauma
- Flashbacks, where you feel or act as though the event is happening again
- Emotional distress when something reminds you of the trauma
- Physical reactivity to reminders, such as a racing heart, sweating, or nausea when you encounter something that triggers a memory
These symptoms are what most people associate with PTSD. The key feature is that the trauma doesn’t stay in the past. It replays in your mind, your emotions, or your body as though it’s still happening.
Criterion C: Avoidance
At least one of two avoidance behaviors must be present. You actively try to steer clear of either internal reminders (thoughts, feelings, or memories connected to the trauma) or external reminders (people, places, conversations, activities, objects, or situations that bring the event back). In the DSM-IV, avoidance was grouped with emotional numbing into a single cluster. The DSM-5 separated them, making avoidance its own standalone requirement. This means a person cannot be diagnosed with PTSD without demonstrating some form of deliberate avoidance.
Criterion D: Negative Changes in Thoughts and Mood
At least two of seven symptoms must be present. This cluster captures the way trauma can reshape how you think about yourself, other people, and the world. The seven possible symptoms are:
- Memory gaps about important parts of the traumatic event (not caused by head injury or substances)
- Persistent negative beliefs about yourself, others, or the world (“I am broken,” “No one can be trusted,” “The world is completely dangerous”)
- Distorted blame, where you persistently blame yourself or others for causing the trauma or its consequences in ways that don’t match reality
- Ongoing negative emotions such as fear, horror, anger, guilt, or shame
- Markedly reduced interest in activities that used to matter to you
- Feeling detached or estranged from other people
- Persistent inability to feel positive emotions like happiness, satisfaction, or love
This cluster is one of the bigger changes the DSM-5 introduced. Previously, these symptoms were bundled with avoidance. Splitting them out reflects the understanding that emotional numbing, distorted thinking, and avoidance are distinct processes that don’t always travel together.
Criterion E: Changes in Arousal and Reactivity
At least two of six symptoms must be present. These reflect a nervous system stuck on high alert:
- Irritability or aggressive behavior, including angry outbursts with little or no provocation
- Reckless or self-destructive behavior
- Hypervigilance, constantly scanning your environment for threats
- Exaggerated startle response, jumping at sudden noises or movements more than you normally would
- Difficulty concentrating
- Sleep problems, trouble falling or staying asleep
Reckless or self-destructive behavior was new in the DSM-5. It was added to capture patterns like dangerous driving, substance misuse, or other high-risk actions that often follow trauma but weren’t explicitly listed before.
Criteria F, G, and H: Duration, Impact, and Exclusion
The final three criteria act as diagnostic guardrails. Criterion F requires that symptoms from clusters B through E have lasted more than one month. If someone shows all the right symptoms but has had them for less than 30 days, the diagnosis is acute stress disorder, not PTSD.
Criterion G requires that the symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning. Symptoms that exist on paper but don’t actually interfere with your relationships, work, or daily life don’t meet the threshold.
Criterion H requires that the disturbance is not attributable to the effects of a substance (medication, alcohol, drugs) or another medical condition. A clinician needs to rule out the possibility that what looks like PTSD is actually being caused by something else entirely.
The Dissociative Subtype
The DSM-5 added a dissociative subtype for the first time. A person meets all the standard PTSD criteria but also experiences persistent or recurrent episodes of either depersonalization (feeling detached from your own mind or body, as though you’re watching yourself from outside) or derealization (the world around you feels unreal, dreamlike, or distorted). This subtype recognizes that some people respond to trauma not by becoming hyperaroused but by mentally disconnecting. It’s estimated to apply to roughly 15 to 30 percent of people with PTSD.
Delayed Expression
The DSM-5 also includes a “with delayed expression” specifier. This applies when the full diagnostic criteria aren’t met until at least six months after the traumatic event. Some individual symptoms may appear earlier, but the complete clinical picture doesn’t come together for months or sometimes years. This is not uncommon, and it doesn’t make the diagnosis less valid.
How the Criteria Differ for Young Children
Children aged six and younger have a separate set of adapted criteria. The core structure is the same, but the thresholds and descriptions are adjusted to match what’s developmentally realistic for small children.
The most significant change is that avoidance symptoms and negative changes in thoughts and mood are combined back into a single cluster, and only one symptom from either category is required (instead of the separate minimums adults must meet). This lower threshold reflects the reality that young children often can’t articulate avoidance or internal emotional states the way older people can.
Several specific symptoms were removed or reworded. The “sense of a foreshortened future” was dropped because preschool-age children don’t typically think about their futures in that way. The inability to recall important parts of the event was also removed, since young children’s memory capabilities make this nearly impossible to assess. Diminished interest in activities may show up as constricted play rather than the verbal disengagement an adult might describe. Social withdrawal stands in for “feelings of detachment.” Irritability and anger outbursts were expanded to include extreme temper tantrums. And the old requirement that a child show extreme distress at the time of the event was eliminated, because research showed that many traumatized preschoolers don’t visibly react with distress even when they’re deeply affected.
The requirement that intrusive memories be “distressing” was also loosened. Studies found that young children can have recurrent, unwanted thoughts about a trauma without showing obvious outward distress, which doesn’t mean the memories aren’t affecting them.