There is no laboratory test for PTSD. The diagnosis is based on the clinical history of the patient and the occurrence of a traumatic event. A diagnosis of PTSD cannot be made without a clear history of a traumatic event. According to the U.S. Department of Veterans Affairs, the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) is the gold standard in PTSD assessment.

The American Psychiatric Association (APA) specifies the symptoms and criteria for PSTD in its Diagnostic and Statistic Manual of Mental Disorders. The DSM-5 introduced a subtype of PTSD for children under the age of 7. The following criteria apply to adults, adolescents, and children 6 years of age and older.

Diagnostic Criteria for Posttraumatic Stress Disorder

Criterion: Stressor
The person has been exposed to a traumatic event in which he/she was exposed to death, threatened death, actual or threatened serious injury, or actual or threatened sexual violence in which (one required):

  1. Direct exposure
  2. Witnessing, in person
  3. Indirectly, by learning of a close relative's or friend's exposure to trauma—actual or threatened death of a personal friend or family member must have been violent or accidental
  4. Repeated or extreme indirect exposure to details of such an event (e.g. first responder), not including exposure through electronic media, television, etc.

Criterion: Intrusion Symptoms
The traumatic event is persistently re-experienced in the following ways (one required):

  1. Recurrent, involuntary, intrusive memories (children may express in repetitive play)
  2. Traumatic nightmares (children may have frightening dreams unrelated to the event)
  3. Dissociative reactions (e.g., flashbacks)—brief episodes to loss of consciousness (children may reenact the event in play)
  4. Intense or prolonged distress following reminders of the event(s)
  5. Marked physiologic reactions following exposure to event-related stimuli

Criterion: Avoidance
The person exhibits persistent effort to avoid distressing event-related stimuli (one required)

  1. Event-related thoughts/feelings
  2. Event-related reminders (e.g., people, places, etc.)
  3. Marked loss of interest in activities significant prior to the event
  4. Detachment or estrangement from others
  5. Persistent inability to experience positive emotions

Criterion: Alterations in Arousal and Reactivity
Event-related alterations (two required)

  1. Irritable or aggressive behavior
  2. Self-destructive or reckless behavior
  3. Hypervigilance
  4. Exaggerated startle response
  5. Difficulty concentrating
  6. Sleep disturbances

Criterion: Duration
Symptoms persist longer than one month

Criterion: Functional Significance
Significant symptom-related distress or impairment

Criterion: Exclusion
Disturbance does not have another cause (e.g., medication, substance abuse, other condition)

Diagnostic and Statistical Manual of Mental Disorders, 5th ed. 2013. Washington, DC: American Psychiatric Association (APA).

Another tool used to evaluate symptoms of PTSD is the Clinician-Administered PTSD Scale (CAPS), a self-reporting questionnaire that assesses the nature of trauma, the patient's current condition, and the prognosis. The CAPS also helps identify associated conditions or complications, such as guilt and an impaired sense of surroundings.

PTSD Differential Diagnosis

Other conditions cause many of the symptoms experienced in PTSD and these conditions must be ruled out. Additionally, conditions such as substance abuse and depression develop as complications of PTSD. Ultimately, the distinguishing factor is the fact that the patient has experienced a severe trauma.

Some of the conditions that must be ruled out include the following:

  • Adjustment disorder
  • Depression
  • Panic disorder
  • Substance abuse or dependence disorder

Furthermore, malingerers—that is, people who falsely claim to be traumatized—sometimes feign PTSD symptoms in order to win money in a court case as compensation for "emotional suffering."

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 31 Jan 2001

Last Modified: 01 Oct 2015