Pain and Emotional Emotional

C biditi Comorbidities: When P i a nTreatment Treatment Alone isNOT En

Michael Michael E. Clark, Ph.D.

MHBS Pain Programs Programs Leader, Leader, Tampa VA

Co‐Chair, VA National National Pain Management Workg p rou

Member, Member, VA National National Pain Management Management Strategy Strategy Coordinating Coordinating Com

Com

Associate Associate Professor, Professor, Dept. of Psychology, Psychology, University University of South Florida Florida
Disclosures

Financial Disclosure

Michael E. Clark, Ph.D. has no financial dis

Grant Support

This presentation is supported in part by dobtained via a VA HSR&D‐funded research (SDR‐07‐047).Any opinions or conclusions presented are the author and do not necessarily reflect tthe Department of Veterans Aff i a rs.

Clark 2012 
Objectives

Briefly Briefly review the pain characteristics characteristics characteristics

associated associated with OEF/OIF/OND OEF/OIF/OND injuries

injuries

Describe Describe Describe Describe the constellation constellation constellation constellation of symptom

symptom

symptom

symptom

prevalence prevalence that characterize characterize Post‐dep

Multi‐symptom symptom symptom Disorder Disorder Disorder (PMD).Identify Identify alternative alternative integrated integrated care tre

tre

strategies strategies for PMD, and summarize summarize th

outcomes outcomes associated associated with this treatm

treatm

approach.

Clark 2012 
Primary Patient Patient Populations ulations

OEF/OIF/OND

Active duty or v

OEF/OIF/OND Less severe inju

general health Mild TBIs comm

OEF/OIF/OND

Polytrauma

Active duty or v

Polytrauma

Present with seinjuries, typicalrelatedModerate to secommon

Clark 2012 
Complexity Complexity of Polytrauma Polytrauma Pain

Polytrauma 

Hearing TBI

Loss & 

Tinnitus

Otalgia

S i

Pain

SCI

tus

Nerve 

Surgic

revisio

Orthopedic & 

Soft Tissue 

Trauma

SCI

Amputations

Injury

Neuropathic 

Pain

Trauma

Phantom

Pain Nociceptive Pain

Clark 2012 

Adapted with permission 
Polytrauma Pain Characteristics

Pain prevalence prevalence = 96%

Headaches and cervical pain from tra

brain injuries and blast injuries (65%)

Extremity pain from blast injuries (55Neuropathic pain from fasciotomies fasciotomies (Phantom limb pain from amputations Back pain (20%)Burn pain from blast injuries (10%)Diffuse pain from numerous soft tissu

shrapnel wounds (10%)

Clark, Bair, Buckenmaier III, Gironda

Clark, Scholten, Walker, & Gironda, 2

Clark, Walker, Gironda, & Scholten, 2

Clark 2012 
Polytrauma Pain Course

10

Mean Pain NRS Scores

4

6

8

0

2 3.0

7.0

6.2

4.8

5.0

Pre‐deployment Blast exposure 3 Months

6 Months

9 Months

Clark 2012 
Course of Pain: Predeployment Predeployment Predeployment Predeployment Bac

9

10

Back Pain

5

6

7

8

9

0

1

2

3

4

3.0 5.0

4.0

4.0

0

Pre‐deploy Blast

3 Months

6 Months

9 Months

3.0 

Clark 2012 
Course of Pain: Soft Tissue In

Back Pain Shrapnel

9

10

ac a S ap e

5

6

7

8

9

9.0

0

1

2

3

4

0.0

6.0

4.0

2.0

0

Pre‐deploy Blast

3 Months

6 Months

9 Months

Clark 2012 
Course of Pain‐ Blast‐relatedHeada

Back Pain Shrapnel Headache

Course of Pain Blast relatedHeada

9

10

ac a S ap e eadac e

6

7

8

9

2

3

4

5

0.0

4.0

6.0 7.0 7.0 

0

1

2

Pre‐deploy Blast

3 Months

6 Months

9 Months

12 

Clark 2012 
Course of Pain‐ Burns

Back Pain Shrapnel Headache Burn P

9

10

5

6

7

8 10.0

6.0 7.0

2

3

4

5

0.0

5.0

0

1

Pre‐deploy Blast

3 M h ont s

6 Months

9 Months

12 M

Clark 2012 
Course of Pain‐ Surgical Revisions

Back Pain Shrapnel Headache Burn Pain 

9

10

6

7

8

9.0

8.0

3

4

5

0.0

0.0 2.0

0

1

2 

Pre‐deploy Blast

3 Months

6 Months

9 Months

12 Mon

Clark 2012 
Combined Course of Polytrauma P

Back Pain Shrapnel Headache Burn Pain 

Combined Combined Course of Polytrauma Polytrauma P

9

10

6

7

8

3

4

5

0

1

2

Pre‐deploy Blast

3 Months

6 Months

9 Months

12 Mont

Clark 2012 
Polytrauma Pain Course

POST-ACUTE PAIN

Surgical Revision & Breakthrough

ACUTE 

Transition to chronic pain via unremitting acute pain

g

Pain

g

Other Iatrogenic Pain

PAIN 

Transition to chronic pain via unremitting acute pain

Post-Traumatic Stress

Reaction & Other

Psychosocial Factors

Pain Associated with 

Prolonged Tissue Healing

Clark, Bair, Buckenmaier III, Gironda, & Walker, 2007

Clark 2012 
Emotional Emotional Injuries

Photo by Jim MacMillan, Associated Press, © 2

Clark 2012 
Foundations of PMD

2003‐2006

Provided Provided early data on the prevalence prevalence of pain amwith pol t y rauma (75‐88%) and OEF/OIF OEF/OIF OEF/OIF returnees 

Identified Identified frequent frequent overlap overlap of pain, mTBI, PTSD, a

emotional symptoms

2007

Initiated Initiated first VA funded study examining examining pain and 

comorbidities comorbidities among veterans veterans and service service memb

memb

2008

Developed Developed the “P3” description description (pain, PTSD, and p

concussive disorder)

2009‐2010

Developed and published the concept of PMD

2010

Implemented the VA’s first interdisciplinary integrp g ro ram to treat PMD

Clark 2012 
Sy p m tom Overlap ( ) P3

Lew, Otis, Tun, Kerns, Clark, &Cifu, 2009

Sample = 340 OEF/OIF outpatients at BostonVA

TBI/Pain

5.3% 10.

12.6%

Pain,TBI, & PTSD

5 3

Overall prevalence:

42.1%

6.8% 16.5%

Overall prevalence:Pain 81.5%

TBI 68.2%

PTSD 66.8% PTSD 2 9%.

Clark 2012 
PMD Definition

PMD refers to “...a constell i at on of

overlapp g in p yh sical and emotion

symptoms common among OEF/Oservice members members that negatively negatively 

Quality of Life, daily function, an

transition transition to life as a civilian civilian ”.

Walker, Clark, & Sanders, 2010

Clark 2012 
PMD Sy p m toms

Sleep Disturbance A thLow Frustration

Tolerance/Irritability

ApathyPersonality ChaSubstance Misu

/ y

Concentration/Attention/Memory Problems

Substance Misu

(including opioi

Activit Activity Avoidan

Avoidan

FatigueHeadaches

l kl l d

y

KinesiophobiaEmployment Employment or 

Musculoskeletal Disorders diffi lti

(i.e. chronic pain)

Affective Disturbance

difficultiesRelationship co

Affective Disturbance Hypervigilance Hypervigilance

Clark 2012 
Latest Data

Research Data

Longitudinal (12‐month) VA‐funded two‐si

353 participants participants recruited recruited either from loca

OEF/OIF/OND OEF/OIF/OND registries registries or the polytrauma polytrauma 

care

First study to use validated validated structured structured clini

clini

interview interview (M.I.N.I.) (M.I.N.I.) to establish establish DSM‐IV dia

along wi ht muli l t p e symptom symptom and f i unct on 

Clark 2012 
Demographics

Age (years) (years) 35.1 Education Education (years) (years) Sex Duty Status at Baseline Baseline

Male 91.1% Active Duty 

Female 8 9%. Inactive Inactive Reserve Reserve 

Race Active Reserve 

Caucasian 77.4% TDRL Hispanic 10.0% Completed obligations 

1 Black 9.5% Service Service Branch1

Other 3.1% Army 

Marital Marital Navy 

Never Married 24.2% Air Force Married 52.4% Marines Divorced/Sep 16.4% National Guard 

Living with someone 6.7% Deployed Deployed from

Other 0 3% Active duty Other

0.3% Active duty 

Employment Status Inactive Status reserve 

Full‐time 54.3% Active reserve Part‐time 7.5% Deployed Deployed to

Unemployed/looking 11 1% OEF only Unemployed/looking 11.1% OEF only Unemployed/not looking 0.8% OIF only 

Disabled 5.8% Both OEF/OIF Student 15.9% Total deployment months 

Retired 1.7% Mean months since return 

Other 2.9%

Clark 2012 
Injuries and Pain

Injury Onset* Injury Type**

No Injuries Reported 13.9% Orthopedic 52

Pre‐service 1.4% Soft Tissue 4

Pre‐deployment 12.6% Closed Head Injury 33

Combat 37.3% Penetrating Wound 9Non‐combat 38 2%. Ear 6 Post‐deployment 3.6% Other 5Post‐service 0.6% Burns 3

Inj y ur Method** Method** Open Head Inj y ur 1

Blast 31.3% Amputation 1Fall 16.1% Eye 1Vehicular 14.0% Spinal Cord Injury 0Shrapnel 4.5% Years since injury 

GSW 1.0% # Blast Exposures Exposures 7

Other 46.8% Distance Distance from closest closest blast (feet) 3

Primary Pain Location***

Back 33.5% Lower extremities 18

extremities 18

Head/Neck Head/Neck 25.0% Torso 2

Upper extremities 15.8% Other 4

Clark 2012 
Mental Health Issues

Current Current or prior MH problem problem 66.9% Reported Reported impairments

Onset of MH problem* problem* Activity 

Pre‐service 5.9% Sleep 

Pre‐d l ep oyment 7 1%. R il ecreational Combat non‐blast related 2.9% Occupational 

Combat blast‐related 13.8% Emotional 

Non‐combat/during

deployment 13.8% Social 

Post‐deployment deployment 50.6% Familial Familial Post‐service 5.9% Sexual 

Resolution Resolution of MH problem problem

Before deployment 1.3% After deployment 

During deployment 2.1% Ongoing‐ not resolved 

Clark 2012 
DSM‐IVDiagnoses

Anxiety Anxiety SUDs

Panic disorder 18.1% ETOH dependence 

Agoraphobia 28 7%. ETOH Abuse Social Phobia 9.5% Opioid Dependence 

Obsessive‐compulsive disorder 12.5% Opioid Abuse 

Generalized Generalized Anxiety Anxiety Disorder Disorder 16.7% Other Substance Substance Dependence Dependence PTSD 26.5% Other Substance Abuse 

1 or more anxiety anxiety disorders disorders 49.9% Polysubstance Abuse 

Depression Depression 1 or more SUD 

Major Depression 29.5% Postconcussional Disorder Disorder Dysthymia 6.6% Mood Disorder with Psychotic Feat

Hypomania 23.1%

1 or more depressive depressive disorders disorders 45.4% At least 1 M.I.N.I. M.I.N.I. Axis I Diagnosis* Diagnosis* 

Pain

Any Pain Present Present 86.6%Significant Significant Pain Present Present Present 55 9%.

Clark 2012 
Prevalence of Diagnoses

60%50%

s

30%40%

nt of case

20%

Percen

0%

10%

No Dx Sig. Pain Mood Anxiety

(other

than

PTSD)

PTSD SUD PC

(mT

Clark 2012 
MultipleDiagnoses

60503040

of Cases

2030

Percent

10

0

No Dx 1 Dx 2 or more D

Clark 2012 
Frequency Frequency of Sleep Problems Problems by 

100

708090

ses

506070

of Diagnos

3040

Percento

0

1020

Clark 2012 
Most Frequent Frequent Comorbid Comorbid Diagn

Diagn

2520

es

15

nt of Case

5

10

Percen

0

Sig Pain, PTSD,

& Mood

Sig Pain, PTSD,

& Anxiety

Sig Pain, PTSD,

Mood, &

Anxiety

Sig Pain, SUD,

& Mood

S

Clark 2012 

Anxiety
Summary

Almost 2/3rds of participants participants met criteria criteria femotional disorderThe majority majority of participants participants had more than 

that met diagnostic diagnostic diagnostic diagnostic criteria criteria criteria criteria (i e . ., PMD).

Most common diagnoses diagnoses among OEF/OIF/O

OEF/OIF/O

personnel personnel personnel personnel receiving receiving receiving receiving or registered registered registered registered for VA car

two VA sites were pain, mood disorders, disorders, an

an

disorders disorders disorders disorders (other than PTSD), PTSD, Substan

Substan

SubstanSubstan

Disorders, Disorders, mTBI, and psychotic psychotic disorders disorders, in 

Sleep problems problems were associated associated associated with all dia

diadia

mTBI (1.9%) and PTSD (0.3%) almost never 

the absence absence absence absence of the other comorbidities comorbidities comorbidities comorbidities we 

Clark 2012 
PMD in Post Deployment Deployment Deployment Cli

Brief review of data p y reviously presented bfrom Tampa VAALL OEF/OIF/OND dep y lo ees reg g istering for Tampa VA are screened for PMDScreening includes an interview with a MH several screening instruments that are used 

potential problem areas

Those who verbally report MH or PMD pro

those who score above certain cutoff value

screening instruments are eval d uate more 

referred for indicated services

Clark 2012 
Results( ) n=356

Measure Measure Domain Range Threshold* Threshold* M (SD) 

GAD‐7 Anxiety Anxiety 0‐21 > 10 7.4 6.6 

PHQ‐9 Depression ression 0‐27 > 10 7.8 7.0 

PCL PTSD 17‐85 > 50 37.6 19.5 SPQ Sleep C lit omp aints 0‐20 > 12 9 8. 7 1. PHQ‐15 Health Complaints Complaints 0‐30 > 10 8.5 5.8 SA‐5 Alcohol Alcohol Subtest only # Drinks/week Male > 15 9.1 14.0 

(Composite score = days/wk days/wk

x drinks/sitting) Female> 8 4.6 6.6 x drinks/sitting)

NRS Pain Avg in past wk 0‐10 > 4 3.6 2.8 

*Cutoffs reflect MODERATE or higher scores Agliata, Takagishi, Clark, & 

Clark 2012 

*Cutoffs reflect MODERATE or higher scores g , g , , 
Number of Problem Problem Problem Areas

100.0%

80.0%

100.0% 74.8%

56.7%

40 0%60.0%

25 2%

43.2%

36.5%

28.2%

19

0 0%

20.0%40.0% 25.2%

18.1% 13.5%

6.7% 8.3% 9.2% 15.

0.0%

0123456

Exact % Cuumulative %

Clark 2012 
Implications

Deployment‐related related physical physical and emotion

emotion

problems problems overlap overlap and coexist. coexist. PTSD and m

almost never occur without without without without other comorbi

comorbi

comorbicomorbi

There is substantial substantial evidence evidence in the literatu

literatu

these comorbidities comorbidities comorbidities can interact interact interact (strongest (strongest (strongest 

mTBI, and PTSD).

The complexity complexity complexity complexity and challenges challenges challenges challenges represented represented represented represented 

may require require alternative alternative treatment treatment method

method

INTEGRATED CARE.

Clark 2012 
Traditional Traditional VA Sp y ecialty Care

OEF/OIF/OND Patients

Meet criteria Do not meet crite

PTSD Tx

Program

TBI Tx

Program

Pain Tx

Program Program Program

Primary Care Tx

Clark 2012 
Alternative Alternative Model of Sp y ecialty C

OEF/OIF/OND Patients

M lti l Multiple S t ymp oms Di t scre e Di d sor er

I d OEF/OIF/OND C Specialty Integrated OEF/OIF/OND Care

for PMD

p y

Programs

(PTSD;

mTBI; Pain)

Primary Care Tx

Clark 2012 
Advanta Advantages of Integrated Care

Provides comprehensive, multi‐symptom casingle program program at a single location location by a gro

providers providers who share a common philosophy philosophy 

treatment.Integrated Integrated evaluations evaluations may provide provide a more picture picture of an individual’s individual’s individual’s individual’s functioning functioning functioning functioning than s

s

ss

focused evaluations.

Facilitates Facilitates a continuum continuum of care rather than 

care.

Addresses Addresses Addresses Addresses the specific specific specific specific problem problem problem problem symptoms symptoms symptoms symptoms a

their interactions.

Clark 2012
Centerfor Post‐deployment H

and Education Education (CPHE) Treatm

Treatm

Interdisciplinary including individual and gr

therapy, physical therapy, and medication

managementWeekly group and individual sessionsTwo tracks: Core ( ) mandatory) and modular

(content specific)

Treatment duration averages between 3 ( 

C

(Focused) months, range between 8 weeks 

monthsOutcome measures administered at admissprior to discharge

Clark 2012 
PMD Integrated Care at Tampa 

Post Deployment Clinics Polytrauma Teams MH, PC, W

W

g p

l / l Polytraum

TBI Tx

Evaluation/Tx Planning

Required Required Core Treatment: Treatment:

Core Group (PMD intro; Sleep

Polytraum

Pain Tx

Core Group (PMD intro; Sleep

Hygiene, Relaxation Skills; SUD );

Individual; Individual; Med management; management; PT

HE

Optional Focus Treatments Treatments:

Anger Management

Fear/Avoidance

PTSD T

Substan

CP

Cognitive Adaptation

Headache Management

Pain Rehabilitation

R l ti hi Eh t

Abuse 

Voc Reh

Relationship Enhancemen ancement

Clark 2012 
CPHE Measures

NRS: Numeric Numeric pain rating scale(0‐10)

M2CQ: Military Military to 

( ) transition transition adjustm

ustm

SA5: NIDA alcohol alcohol use measure measurePOQ‐VA: Pain Outcomes Outcomes

j 

CES‐D: Center for

Epidemiologic Stu

Questionnaire, a multi d i l ‐domain

measure of pain‐relatedimpairment airment or disabilit disability

depression scaleNSI: Neurobehavi

p y Symptom Invento

Invento

ADLs\

MobilityVit lit POQ

y p 

(Postconcussive SySTAI‐T: Trait anxie

anxie

Vitality POQNegative AffectFear

SWL: Satisfaction Satisfaction 

scale

PCL‐C: PTSD symp

SIS (symptom (symptom implausibility) implausibility)

SPQ: Sleep problems problems

PCL‐C: PTSD sympTSS‐P: Treatment Treatment 

Scale

Clark 2012 
Descriptives(n=31graduates) graduates)

Mean age 36.58 yrsMean education education 13.74 yrsMean deployment deployment 14 78 . monthsMale 86.7%Married Married 57.8%Blast exposure exposure 53.3%Blast injury 35.6%Loss of consciousness consciousness 28 9%.Headaches 64.4%

Clark 2012 
Outcome Measure Measure Pre Tx Post Tx 

NRS 6 16 . 5 06 . SA5 3.69 2.62 

POQ‐ Mobility 19.45 16.42 

POQ‐ ADLs 11.10 8.23 

POQ‐ Vitality 17.73 16.03 

POQ‐ Negative Affect 30.27 24.03 

POQ‐ Fear 11.77 11.52 

POQ‐ SIS 38.33 30.93 

M2CQ 2.73 1.98 

CES‐D 30 10 . 23 90 . NSI 42.77 34.32 STAI‐T 53.90 47.65 SWL 14.13 17.19 PCL‐C 57.35 50.55 SPQ 15.33 12.53 Clark 2012 
Outcomes 1

6.2

5.1

5.06.0

3.7 4.0

2.7 2.73

1

2 03.01.02.00.0

Pain NRS* SUD severity (NIDA) M2CQ*

PreTx Post Tx *differences 

Clark 2012 
PainOutcomesQuestionnaire‐V

40.00

30.27 

30.0035.00

19 45

25.00 24.03

19.45

17.73

11 77

16.42 16.03

15.0020.00

11.10 11.77

8.23

11.52

10.00

0.005.00

MOBILITY* ADLs* VITALITY NEG *differences significant AFFECT* FEAR 

PreTx Post Tx

g

Clark 2012 
Symptom Measures

53.90

60.00

42.77

47.65

50.00

30.10

34.32

30 0040.00

23.90

20.00

30.0010.00

0.00

CES‐D* NSI* STAI‐T* 

PreTx Post Tx *diff

Clark 2012
Sleep and Satisfaction Satisfaction With L

15 33

17

16 00 15.33

14.13

12.53

14.00

16.0010.0012.00

6.008.002.004.000.00

SPQ * SWL*

PreTx Post Tx *diffPreTx Post Tx

Clark 2012 
Satisfaction Data

10.00

8.009.006.007.004.005.002.003.00

.00

1.00

Satisfaction with Tx Staff warmth & respect Staff skills Availability of Tx R

Clark 2012 
Case Example

24‐year‐old, married, unemployed male, 3 military military service, service, Iraq for 1 yr (2008‐2009), dCombat and trauma exposure, multiple blafrom lifting lifting injury while on active dutyNo prior medical medical problems problemsNo prior mental health history history history history or treatmen

treatmen

treatmentreatmen

Presenting complaints (onset 2009):

LBP secondary secondary to HNP, depression depression, anxiety anxiety, irrit

irrit

sleep, marital problems, physical aggression tow

hypervigilance, feeling overwhelmed, intrusive 

flashbacks), cognitive difficulties (sluggishness; somatic symptoms (racing heart, SOB, night swappetite appetite, difficulty difficulty adjusting adjusting to civilian civilian life, rece

“spice”

Clark 2012 
CPHE Treatment

Weekly CPHE core groups (Introductio

(Introductio

PMD; Sleep Hygiene; Hygiene; Hygiene; Relaxation Relaxation Relaxation Skills

SkillsSkills

Substance Abuse)

Physical Physical Therapy Therapy for LBP 1‐2 sessions sessions 

with home exercises

Individual Individual therapy therapy focusing focusing on fear re

re

relaxation relaxation relaxation training, training, training, activation, activation, activation, relatio

relatio

issues, issues, and substance substance use

Meds: D/C muscle relaxant; relaxant; relaxant; relaxant; NSAIDs an

Tramadol Tramadol for pain (via Primary Primary Care)

Tt t rea ment d ti ura on approxi tl ma e y 6 m

Clark 2012 
Outcomes

Measure Pre‐Tx Post‐

POQ‐Pain Score 10 5

POQ‐Mobility Interference 35 28POQ‐ADL Interference 28 0POQ‐ Vitality Vitality (strength (strength & endurance) endurance) 26 32POQ‐Negative Affect (depression & anxiety) 46 41M2CQ (military to civilian transitionproblems) 3 3CES‐D (depression) 41 30NSI (TBI/behavioral symptoms) 43 33NSI 

(TBI/behavioral symptoms) 43 33

STAI‐T (Trait Anxiety) 65 57SWL (Satisfaction with Life) 5 8*PCL‐C (PTSD checklist‐ civilian version) 68 54

SPQ (sleep problems questionnaire) 19 14

Al h l co o use score (NIDA) 1 3

Clark 2012 
Qualitative QualitativeOutcomes Outcomes and Dispo

Dispo

Tramadol Tramadol and NSAIDs reduced reduced 50%Began college‐ “A” student

Discontinued Discontinued use of “spice” (note slig

increase increase in ETOH however) however)Filed for divorceRe‐established social contacts

Continues Continues home exercise exercise program program

MH follow up arranged PRN with our deployment deployment clinic PMD staff, but to dadeclined further contact contact

Clark 2012 
Selected References

Clark, M.E., Scholten, J.D., Walker, R.L., & Gironda, R.J. (2009). Assessment and treatment of pain associated with com

Pain Medicine, 10(3), 456‐469.

Clark, M.E., Walker, R.L., Gironda, R.J., & Scholten, J.D. (2009). Comparison of Pain and Emotional Symptoms in Soldie

Aspects Aspects of Blast Exposure Exposure. Pain Medicine Medicine, 10(3), 447‐455.

Clark, M.E., Bair, M.J, Buckenmaier III, C.C., Gironda, R.J., and Walker, R.L. (2007). Pain and OIF/OEF combat injuries: 

and practice. Journal of Rehabilitation Research & Development, 44, 179‐194.

Dobscha, SK, Clark, M.E., Morasco, B.J., Freeman, M., Campbell, R., & Helfand, M. (2009). A Systematic Review of the 

Patients with Polytrauma. Pain Medicine, 10(7), 1200‐17.

Gironda Gironda, R J. ., Clark, M E. ., Ruff, R., Chait, S., Craine, M., Walker, R L. ., & Scholten Scholten, J. (2009). Traumatic Traumatic Brain Injury, Pol

Challenges and Treatment Strategies for Polytrauma Rehabilitation. Rehabilitation Psychology, 54, 247‐258.

Gironda, R.J., Clark, M.E., Massengale, J.P., & Walker, R.L. (2006). Pain among veterans of Operations Enduring Freed

Medicine, 7, 339‐343.

Hoge, C.W., McGurk, D., Thomas, J.L., Cox, A.L., Engel, C.C., & Castro, C.A. (2008). Mild traumatic brain injury in U.S. S

New England Journal of Medicine, 358( ), 5 453‐63.

Lew, H.L., Otis, J.D., Tun, C., Kerns, R.D., Clark, M.E., & Cifu, D.X. (2009). Prevalence of Chronic Pain, Posttraumatic Str

concussive Symptoms in OEF/OIF Veterans: The Polytrauma Clinical Triad. Journal of Rehabilitation Research & 

Kalra, R., Clark, M.E., Scholten, J.D., Murphy, J.L., & Clements, K.L. (2008). Managing pain among returning service me

25, 36‐45.

Ruff, R. L., Ruff, S. S., & Wang, X. F. ( ) 2008 . Headaches among Operation Iraqi Freedom/ pO eration Enduring Freedom 

traumatic brain injury associated with exposures to explosions. Journal of Rehabilitation Research and Develop

Sayer, N. A., Chiros, C. E., Sigford, B., Scott, S., Clothier, B., Pickett, T. et al. (2008). Characteristics and rehabilitation o

with blast and other injuries sustained during the Global War on Terror. Archives of Physical Medicine and Reh

Shipherd, J.C., Keyes, M., Jovanovic, T., Ready, D.J., Baltzell, D., Worley, V., Gordon‐Brown, V., Hayslett, C., & Duncan, 

treatment for posttraumatic stress disorder: What about comorbid chronic pain? Journal of Rehabilitation Res

153‐166.

Walker, R.L, Clark, M.E. & Sanders, S.H. (in press). The “Post‐Deployment Multi‐Symptom Disorder”: An emerging syn

treatment paradigm. Psychological Services.

Walker, R.L., Clark, M.E., Nampiaparampil, D.E., Mcllvried, L., Gold, M.S., Okonkwo, R., & Kerns, R.D. (2010). The haza

headache. The Journal of Pain, 11, pp. 297‐302.

Clark 2012