How is PTSD Measured?

To develop PTSD, a person must have gone through a trauma. Almost all people who go through trauma have some symptoms as a result. Yet most people do not get PTSD. A certain pattern of symptoms is involved in PTSD. There are four major types of symptoms: re-experiencing, avoidance, numbing, and arousal. To learn more about these symptoms, see What is PTSD? (en Español).

Deciding if someone has PTSD can involve several steps. The diagnosis of PTSD is most often made by a mental health provider. Please see Types of Therapists for more about the types of mental health providers who diagnose and treat PTSD.

What is a PTSD screen?

A person who went through trauma might be given a screen to see if he or she could have PTSD. A screen is a very short list of questions just to see if a person needs to be assessed further. A positive screen does not mean a person has PTSD. A positive screen means that this person should be assessed further. Fill out a PTSD self-screen on "What Can I Do if I Think I Have PTSD?" (en Español).

What can I expect from an assessment for PTSD?

Assessments for PTSD can vary widely depending on their purpose as well as the training of the evaluator. The evaluator needs to assess the effect a trauma has had on your life. He or she can then judge whether treatment for PTSD is needed. While an interview may take as little as 15 minutes, the most common evaluation takes about one hour. Some PTSD assessments can take eight or more 1-hour sessions. This is more likely when the information is needed for legal reasons or disability claims.

You can expect to be asked questions about events that may have been traumatic for you. You will be asked about symptoms you may have as a result of these events. Assessments that are more complete are likely to involve structured sets of questions. You may be given psychological tests on which you record your thoughts and feelings. Your spouse or partner may be asked to provide extra information. You may also be asked to go through a test that looks at how your body reacts to mild reminders of your trauma.

No matter what your case involves, you should always be able to ask questions in advance. The evaluator should be able to tell you what the assessment will include. You can also ask what information the professional expects to get from the assessment.

What are some of the common measures used?

There are two main types of measures used in PTSD evaluations.

Structured Interviews

A structured interview is a standard set of questions that an interviewer asks. Some examples of structured interviews are:

• Clinician Administered PTSD Scale (CAPS). Created by the National Center for PTSD staff, the CAPS is one of the most widely used PTSD interviews. The questions ask how often you have PTSD symptoms and how intense they are. The CAPS also asks about other symptoms that commonly occur with PTSD.
• Structured Clinical Interview for DSM (SCID). The SCID is another widely used interview. The SCID can be used to assess a range of mental health disorders including PTSD.

Other interviews include:

• Anxiety Disorders Interview Schedule-Revised (ADIS)
• PTSD-Interview
• Structured Interview for PTSD (SI-PTSD)
• PTSD Symptom Scale Interview (PSS-I)

Each has special features that might make it a good choice for a particular evaluation.

Self-report Questionnaires

A self-report questionnaire is a set of questions, usually printed out, that you are given to answer. This kind of measure often takes less time and may be less costly than an interview. These measures provide a single score to measure the amount of distress a person has.

An example of a self-report measure is:

• PTSD Checklist (PCL). The PCL is another widely used measure developed by National Center for PTSD staff. This measure comes in several versions including one for civilians and another designed for military personnel and Veterans.

Other self-report measures are:

• Impact of Events Scale-Revised (IES-R)
• Keane PTSD Scale of the MMPI-2
• Mississippi Scale for Combat Related PTSD and the Mississippi Scale for Civilians
• Posttraumatic Diagnostic Scale (PDS)
• Penn Inventory for Posttraumatic Stress
• Los Angeles Symptom Checklist (LASC)

For more information about PTSD assessment, please see FAQs about PTSD Assessment.