1. A Primer on Using the Clinician Administered PTSD Scale (CAPS)
Dudley Blake, Ph.D. & Pat VanWyk, Ph.D
Greetings! This presentation will introduce you to the Clinician Administered PTSD Scale, or CAPS, which is widely considered to be the “gold standard” for the accurate and reliable assessment of Post-Traumatic Stress disorder. The CAPS is a flexible clinical assessment instrument that can be administered as a diagnostic tool (one-month version) or an ongoing measure of treatment course (one-week version).

2. CAPS Features
Symptom-Based Interview for Assessing and Diagnosing PTSD
Standardized Administration
Week or Month Time Frame
Ratings made for Frequency/Duration and Intensity of Symptom and Disorder
Rating Continua with Anchor Descriptors
Well Validated
The CAPS has numerous features that set it apart as a valuable, reliable tool for assessing Post Traumatic Stress Disorder
The CAPS is a symptom-based Interview for assessing and diagnosing PTSD. It has components that allow for trauma assessment, for making global determinations (e.g., PTSD impact/severity and assessment integrity), and to assess common associated symptoms, but the strength of the instrument is in assessing the 17 core symptoms and deriving diagnostic information.
A clear strength of the CAPS is its reliance on standardized administration. Standard or required questions are used throughout the CAPS (with flexibility to us appropriate and suggested prompt questions), and symptom queries are tied strictly to a consistent time frame (one week or one month. This standardization means that a clinician administering the CAPS at one point in time is doing about the same thing as another CAPS interviewer at another point in time or place.
The CAPS is easily adjusted to asses PTSD symptoms during the past month (e.g., for diagnosis) or week (e.g., for monitoring symptoms status of time/treatment). The CAPS is flexible, can be used for repeated measurement (pre-post. over time) AND for establishing diagnostic status (current, lifetime).
Following tradition of E.L.Thorndike (1904), the father of American psychometry [e.g., his classic text, An Introduction to the Theory of Mental and Social Measurement (1904), breaking the units of measurement down into objective, verifiable units), the CAPS relies on ratings made for Frequency/Duration and Intensity of Symptom and Disorder. During Dr. Thorndike’s era, and for much of the time since, a global construct of “severity” was the unit, but severity is a “sloppy” notion, composed of at least frequency, intensity, and duration; in this regard, the CAPS advances our sophistication in assessment and ensures that PTSD data obtained provides a more exacting picture of the topography and impact of an individual’s PTSD symptoms.
CAPS five-point rating continua include anchor descriptors with behavioral referents. Many existing measures are comprised of dichotomous, “yes/no” items, which tend to lose a good deal in measurement and interpretation; CAPS rating continua with 5 options provide a much richer gradation for measurement and a more meaningful source of information, without the complexity and practical difficulty inherent in making evaluations with 7 or 9 rating options.
The CAPS is well validated. Seminal work by several investigators in the field, including Frank Weathers and Edward Blanchard, have established that the structure and content of the CAPS provide reliable and valid assessment of the construct, PTSD.

3. Advantages of CAPS Interview
Provides fine-grained, multi-dimensional data on PTSD symptom status
Serves as a clinical assessment tool
The CAPS provides a rich, reliable source of information about an individual’s PTSD status. Using the CAPS, information is obtained about the frequency of specific symptoms and symptom clusters, as well as the intensity of the symptoms experienced. This information is obtained in the context of interpersonal interaction, requiring professional skills and finesse, and lending itself to further clinical assessment and introducing another clinical context within the treatment endeavor.

4. General CAPS Interview Conventions
Establish positive interview tone
Explain interview purpose (i.e., assess possible problems in past week/month)
Predict and normalize arousal or temporary symptom increase
Describe interview structure, e.g., will ask two sets of questions about 20 or so problems
Encourage interviewee to give specific (brief) answers to specific questions
In many respects, these CAPS interviewing conventions are probably just good interviewing skills.
The CAPS is best administered within the context of a positive interview tone. The interviewer can establish this tone by initiating the interview using a pleasant, casual conversation at the start. This initial “chit chat” will help the interviewee become comfortable with the interviewer and the interview format.
The CAPS interviewer should also explain why the interview is being used, e.g., to obtain information about possible problems the individual may have that stem from his or her trauma exposure, either in the past week or the past month.
The CAPS interviewer should also let the interviewee that some of the questions may lead to emotional or physiological arousal, assuring them that this arousal will be temporary or transient. The interviewee should understand that arousal or upset is understandable and predictable; uncomfortable reactions are “normal.” At the same time, it is also a good idea to let them know that usually that emotional arousal does not happen (to reduce the expectation or demand characteristic that they will get aroused).
It is very helpful for the interviewer to describe the overall structure of the CAPS interview. For example, The CAPS interviewer should inform the individual that he or she will be having them complete a brief rating scale about stressful events they may have encountered during their life, followed by some questions designed to determine the impact of any stressors identified (and which were the most upsetting ones). Next, the interviewer should inform the interviewee that he or she will be asking 20 or so questions about possible problems they may be experiences that are related to the identified stressor(s).
The CAPS interviewer should encourage the individual to listen carefully to each question asked, and try to respond specifically to each question, i.e., they do not need to give examples, justify their responses, or elaborate in any way---the interviewer should let the interviewee know that you the CAPS includes decision rules to follow and that, if further information is required, he or she will be asked about it. This emphasis on specificity and keeping answers short is important for ensuring that the interview does not become an informal discussion about their problems and become overly time-consuming.

5. Assessing Traumatic Stress Exposure
Orient the interviewee to trauma assessment
Administer the LEC
Ask trauma questions
» Objective features of the trauma
» Subjective response to trauma
Orienting the Interviewee. Let the interviewee know that the entire CAPS interview takes roughly an hour. It will start by establishing what the individual has experienced in the way of traumas, determining which traumas are currently causing the most distress, and then asking questions regarding the frequency and intensity of PTSD symptoms they are currently experiencing. CAPS includes an example of this script that you can use or tailor to your respondent.
In talking with the interviewee about the nature of the assessment, inform them that you will be asking them about some difficult or stressful things that sometimes happen to people. The Life Events Checklist (LEC) lists an array of potentially traumatizing events, including natural disasters, accidents, physical/sexual assaults, and military experiences, as well as a option to identify any other event the interviewee may have experienced. This trauma assessment in the LEC and CAPS also allows the respondent to categorize how they experienced the event (on a scale qualifying the event as “directly,” “indirectly,” or “not at all”) .
For each traumatic event listed, assess both objective and subjective information about the event. For example,
Objective: What happened, age, others involved, where, death/injury, etc.
Subjective: How they responded, such as the emotions they experienced (e.g., fear, helplessness, horror), beliefs during the event, bodily sensations experienced,
feelings, how did the interviewer felt after the event (e.g., after “adrenaline rush” was over)

6. DSM-IV PTSD Stressor Criterion (Criterion A)
To be considered a trauma, a stressor must involve…
Actual or threatened death or injury to oneself or to others, and
The person must have responded with intense fear, helplessness, or horror
Many respondents may have multiple traumas. Therefore, it is important to establish which of the trauma or traumas are currently causing the most distress and impairment before beginning to ask the structured CAPS questions. An initial task for the CAPS interviewer is to assess which were the “worst” (most upsetting or debilitating), up to 3 events.
Using the respondent’s information about the worst trauma(s), the CAPS interviewer assesses if the interviewee’ reported stressor(s) meet criteria per DSM-IV for being a traumatic event. Note: the event that may seem objectively to be the most stressful event may not currently be the most distressing, and vice versa.
Some examples of 1: The interviewee reporting that he or she directly experienced combat, a serious vehicle accident, torture, sexual/physical assault, natural/manmade disaster, robbery/mugging, diagnosis of life-threatening illness, witnessing the death/injury of other, unexpectedly seeing dead/dying body or body parts,
and learning a family member’s sudden unexpected death, or diagnosis of one’s child with life threatening illness
Some examples of 2 might include an intense fear of dying/being injured themselves, intense helplessness being unable to help or change the course of events, and intense horror at the sight of event.
For each event, the CAPS interviewer can stop assessing once there is enough information to assess if Criterion A is met

7. CAPS Life Events Checklist (LEC)
Procedure for Assessing Traumatic Events
The LEC is a brief paper and pencil measure that can help a respondent organize and roughly categorize different stressful experiences they may have had during their life.

8. Life Events Checklist
Sixteen event categories and one “other” category
Three Types of Exposure:
Happened to me
Witnessed it
Learned about it
LEC events include experiences that occurred within the lifetime of the individual, both as a child and adult
Interviewee/respondents can check more than one box (e.g., a person could have been injured in a vehicle accident and witnessed a loved one die in that same accident)

9. General CAPS interview Item Conventions
Always ask standard prompt question (or, in some cases, an equivalent)
Rephrase or elaborate on prompt questions, as needed
Offer two (2) rating options, if needed
Frequently repeat ratings back to interviewee
The CAPS interview standard prompt questions are those in bold, the follow-up questions are italicized in parentheses, These questions MUST be asked for standardization of the CAP assessment.
It is acceptable to rephrase or elaborate once you have asked the initial prompt question, to assist your rating of their response. This practice may include using different terms or language that the interviewee is more likely to understand. It can be helpful to take detailed notes in the description/example section of each question to help clarify/justify the rating
If the CAPS interviewer can narrow the ratings down to two options, he or she can offer the interviewee a choice between two ratings, e.g., if the interviewer responds “once in a while” when asked about the frequency of unwanted memories of the event, the interviewer can ask if they have had memories once or twice in the last month, or once or twice a week in the last month.
Remember that the CAPS interviewer, not the interviewee, makes the final judgment about the appropriate rating based upon all the information you have about the respondent, including but not limited to their response to the question, e.g., extra-test behavior such as body language, unlikely or improbable responses to questions, interviewee history known independent of the CAPS interview context.
Check in with the rating the respondent gave, often in the form of a question to confirm it accurately reflects the status of that symptom, for example, “Okay, so you feel you’ve had this problem once or twice in the last month?”

10. CAPS Rating Conventions for Frequency/Duration:
Has interviewee ever had the problem? If yes, has interviewee had the problem in the past month (or past week)? How often or how much of the time in the past month has the interviewee had the problem?
The CAPS method for assessing Frequency of a given symptoms does not assume that the interviewee has or should have a particular symptom
The method involves first establishing whether the interviewee has or has ever experienced the symptom, then establishing whether the symptoms occurred within the standard time frame (past month or past week), and ending with a questions to quantify how often the symptoms occurred within the time frame (how often in past month/week)
Frequency ratings are made on a five point Likert scale from 0 to 4, from least frequent to most frequent. The anchor descriptions or behavioral referents are keys to make valid, reliable rating.

11. Frequency rating prompts for distressing dreams (B-2)
Have you ever had unpleasant dreams about (EVENT)?
Describe a typical dream. (What happens in them?)
How often have you had these dreams in the past month?
As an example, the CAPS frequency item, “Have you ever had unpleasant dreams about (EVENT)?” attempts to establish the presence of a symptom, followed by the question, “Describe a typical dream” (What happens in them? This question aims to assess the distressing nature of the dream as per Criteria B-2: recurrent distressing dreams of the event.) so that the clinician-interviewer can best determine whether these night-time phenomena are in fact related to the trauma (content or theme). If the interview determines that the dreams or nightmares are trauma-related, he or she goes on to assess the frequency of the dream activity in the past month (or week).
The third question assesses the frequency of the dreams in the specified time frame of the CAPS (most typically one month, but can also be one week or lifetime, depending on purpose of the assessment). The next slide shows the frequency rating options for distressing dreams.

12. Frequency rating continua for distressing dreams (B-2)
Never
Once or twice
Once or twice a week
Several times a week
Daily or almost every day
Frequency ratings are made on 5-point continuum from lowest to highest frequency. They are expressed in occurrences during the time frame, as they are in the case of distressing dreams, but, but some items, they are made on percentages of time or opportunity, depending upon the nature of the question, e.g., sense of foreshortened future, loss of interest in previously-enjoyed activities).

13. Frequency/duration rating prompts for feelings of detachment or estrangement from others (C-5)
Have you felt distant or cut off from other people?
What was that like?
How much of the time in the past month have you felt that way?
Again, the first question for “Have you felt distant or cut off from other people?” attempts to establish the presence of that PTSD symptom. If the interviewee’s answer is “yes,” the CAPS interviewer should continue with the next question in the prompts, if “no,” the frequency and intensity rating are recorded as “0 - never/none.”
The frequency/duration second question aims to assess the nature and extent of social detachment as per Criteria C-5: feeling of detachment or estrangement from others.
The third question assesses the frequency of the symptom in the specified time frame of the CAPS (most typically one month, but can also be one week or lifetime, depending on purpose of the assessment)

14. Frequency rating continua for feelings of detachment (C-5)
None of the time
Very little of the time (less than 10%)
Some of the time (approx 20-30%)
Much of the time (approx 50-60%)
Most or all of the time (more than 80%)
Frequency ratings for feelings of detachment are rated on a 5-point continuum, from lowest to highest frequency. They are expressed as percentages of time (unlike distressing dreams, where frequency is rated according to number of events), due to the fact that they are feelings rather than incidents.

15. CAPS Rating Conventions Intensity:
Questions assessing degree of impact that the symptom has had on the interviewee’s life
Behavioral referents of impact that are unique to the symptom (in both prompt questions and rating anchors)
The intensity questions are the questions that assess the presence of “distress and impairment” discussed in the DSM-III-R as necessary components for all diagnosable mental disorders.
Intensity ratings are made on a five point Likert scale from 0 to 4, from least intense to most intense.

16. Intensity rating prompts for feelings of detachment or estrangement (C-5)
How strong were your feelings of being distant or cut off from others?
(Who do you feel closest to? How many people do you feel comfortable talking with about personal things?)
Intensity ratings are based on how strongly the interviewee perceives that he or she feels being distant or estranged from other people.

17. Intensity rating continua for estrangement or detachment (B-2)
No feelings of detachment or estrangement
Mild, may feel “out of synch” with others
Moderate, feelings of detachment clearly present, but still feels some interpersonal connection
Severe, marked feelings of detachment or estrangement from most people, may feel close to only one or two people
Extreme, feels completely detached or estranged from others, not close with anyone
Besides relying on the behavioral anchors found in the intensity ratings, these ratings may be aided by clinical observations, such as,
how much of an impact it has on the interviewee’s life (e.g., estranged spouses or children, lost employment, degree of isolation), whether the symptom interfered with what the interviewee was doing at the time that it occurred, and how long until they resumed that activity, and whether the symptom interfered during the interview or other interactions observed.

18. Challenges in PTSD Assessment
Co-Morbid Disorders
Symptom Overlap
Multiple Traumas
Culture and Language (Ethnic, Gender)
Symptom Over-reporting
Often times PTSD is accompanied by other disorders, commonly referred to as co-morbid or concurrent diagnoses. PTSD’s primary co-morbid disorder are Depression and Substance Abuse. Other possible co-morbid disorder include Dysthymia, Agoraphobia, Obsessive-Compulsive Disorder, Generalized Anxiety Disorder, Panic Disorder, Somatization Disorder, Antisocial Personality Disorder, and Borderline Personality Disorder. Separating out these disorders may have important treatment implications. These disorders should be teased out as much as possible, identifying which symptom most appropriately fits with which disorder. The CAPS interviewer can do this by paying particular attention to the interviewee’s responses, and trying to determine the timing onset of each symptom as well as the “themes” that are attached to each symptom, e.g., sleep disorder might include middle night awakening with startle, hypervigilance, and physiological arousal.
The symptoms of PTSD can be seen in other disorders. Dr. Miles McFall CAPS Training CD-ROM includes a comprehensive, scholarly description of how PTSD symptoms overlap with those of various other mental disorders: Depression (9), GAD (5), OCD (5), Substance Abuse (7), Simple and Social Phobia (4), and Antisocial Personality Disorder (2).
Distinguishing among PTSD problems that are related to specific traumas is another challenge in PTSD, and CAPS, assessment. Here, the notion of “complex PTSD,” in which the trauma survivor’s clinical presentation is complicated and compounded by numerous, often-time different, trauma exposures. In conducting a CAPS interview, the interviewer should have a firm idea about whether he or she is looking to identify PTSD symptoms related to a particular trauma, or is looking to determine the extent of PTSD symptomatology resulting from an amalgam of traumas experienced.
Symptom over-reporting is perhaps the bane of PTSD and CAPS assessment. Individuals with PTSD commonly provide extreme reports of psychological and medical conditions. Some clinical researchers attribute this characteristic to the physiological hyperarousal of individuals with PTSD---these individuals are though to be hypersensitive to their own internal state and hence provide higher reporting about their symptoms than non-trauma-exposed individuals. Others feel that “secondary gain” may be the most important factor; individuals may receive monetary compensation or benefits by reporting symptoms, others may escape responsibility for crimes or other behavior that is deemed unacceptable by others. LaCoursiere (1993) proposed four potential reasons for symptom over-reporting. These include: (1) psychotic disorders/delusions (e.g., non-combat vets listening to combat vets – Ken/partition story), (2) Concealment of other behavior (Walt Y execution story), (3) to gain special attention and status (e.g., as a Vietnam vet with PTSD), and (4) Explaining and covering up a dysfunctional life, with multiple marriages and divorces, poor job history, geographic moves, and substance abuse. These are factor of which to be mindful while conducting the CAPS interview.

19. CAPS Interview Prerequisites
Exposure to PTSD population(s)
Working knowledge of DSM-IV criteria for PTSD
Careful reading of CAPS Administration Manual
Practice, Practice, Practice (first with non-patients, then with patients)
The two populations most heavily studied in regards to PTSD are female survivors of sexual assault and war-zone or combat veterans. This range of trauma populations is by no means exhaustive, and there are likely just as many differences within a population as there are between populations. That being said, it can be helpful to have a solid, working knowledge about a specific population in order to lessen potential stereotypes and unhelpful conclusions.
While the CAPS is an instrument that is tied specifically to DSM-III-R criteria, it is essential that interviewers are familiar with the PTSD symptoms in order to discriminate symptoms that are due to trauma exposure from ones that are unrelated or due to other factors. CAPS interviewers should make note of idiosyncratic manifestations and example of each symptoms as well as common expressions.
The CAPS administration manual is a helpful and relatively brief resource that can answer many questions that come up as you begin to practice the administration. At the end of the manual is a list of CAPS “do’s and don’ts” that is also very helpful.
Practice can occur with many different people: Colleagues, friends, partners are all potential confederates for you initial CAPS experience. It is less important that they portray a specific trauma or population accurately and more important that you get a chance to wrestle with making an accurate rating given their responses. An inter-rater set-up can be helpful, if it is possible, where two people (perhaps one that is a supervisor or more experienced in CAPS administration) rate one respondent simultaneously and then discuss the ratings after the interview has concluded

20. CAPS Training Resources
National Center for PTSD’s website that includes:
CAPS and CAPS-C training manuals
CAPS training DVD ordering information
Information about obtaining CAPS training in the VA
Several very helpful CAPS resources have been produced the National Center for PTSD. Instructional manuals are available for both the CAPS and the CAPS-C (child version); interested clinicians can order a comprehensive DVD with CAPS practice interviews, and professionals can pursue CAPS training available through the Department of Veterans Affairs. These resources are free and helpful, so use them.