We present a selected review of recent research findings concerning psychosocial factors important in chronic pain (so-called "yellow flags" for risk of poor outcomes) and their measurement. We focus on pain associated with temporomandibular disorders, or TMD, because that is the most common chronic orofacial pain condition. However, these yellow flags also are applicable to patients with other orofacial pain conditions, such as trigeminal neuralgia (tic douloureux), postherpetic neuralgia, atypical facial pain, burning mouth syndrome and atypical odontalgia. We also discuss practical aspects of identifying these yellow flags in a clinical setting.

	METHODS

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To identify relevant articles, we conducted two MEDLINE searches for the period 1995 through 2002, and searched our personal files and books. The first MEDLINE search, with the terms "temporomandibular disorders," "assessment" and "psychological," yielded 31 articles, and the second search, with the terms "primary care," "screening" and "psychological disorders," yielded 225 articles. We then reviewed the abstracts of these articles and those of articles in our personal files and books to select those to read for this review. We chose 43 articles and chapters for inclusion—data-based whenever possible—based on their relevance to the topic, recency of publication, comprehensiveness (in the case of review articles) and quality of the journal.

	RESULTS

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Biopsychosocial model of chronic pain. Pain that persists for a long time (typically, longer than three to six months) is considered chronic; often, little or no underlying physical pathology can be found.³ The longer the pain persists, the more opportunity there is for psychosocial factors to be involved in pain and disability. When a thorough assessment fails to identify a specific cause of a patient’s pain and associated problems such as limitations in jaw functioning, dentists may wonder if the symptoms are of psychological origin. Such a dichotomization of pain into somatogenic and psychogenic types is incompatible with the current scientific understanding of pain, and also is clinically nonproductive.

The conditions of patients whose pain and disability are influenced significantly by psychosocial factors are unlikely to improve substantially with dental treatments alone.

More useful is a biopsychosocial perspective.^4–6 In contrast to the biomedical model, which explains pain purely in terms of pathophysiology, the biopsychosocial model views pain, suffering and disability as the result of dynamic interactions among biological, psychological, behavioral, social, cultural and environmental factors. A patient’s experience of pain and response to any treatment for pain are affected not only by biologically determined nociceptive (nervous system transmission) processes, but also by psychological factors such as mood (for example, depression, anxiety) and appraisals (thoughts and beliefs about the pain), as well as by psychosocial factors such as the responses of others (for example, family, friends, co-workers, dentists and other health care professionals). This model is accepted widely and is well-supported empirically for pain as well as for other health conditions.^4,7

The relevance for the dentist who assesses and treats patients with chronic orofacial pain is clear: the conditions of patients whose pain and disability are influenced significantly by psychosocial factors are unlikely to improve substantially with dental treatments in the absence of therapies that modify the psychosocial influences.^8,9

Research findings. Several lines of research have demonstrated the applicability of the biopsychosocial model to the assessment and treatment of patients with TMD. First, researchers^1,10,11 have shown that patients with TMD differ widely with regard to levels of pain, pain-related disability and distress, but physical findings do not appear to explain these differences.^1,2,12 Researchers also have demonstrated that major psychological disorders are common among patients with TMD.^13,14 Finally, psychosocial variables are associated with symptom severity, and indicators of psychosocial dysfunction are associated with worse treatment outcomes in this patient population.^{8,9,11,15–18} Taken together, these findings provide substantial empirical evidence that psychosocial factors play important roles in symptoms, symptom impact and treatment response of patients with TMD.

From a biopsychosocial perspective, it is important to identify both biological and psychosocial contributors to pain, suffering and disability, with improvement in these domains the primary goals of treatment. Dentists who treat patients with chronic orofacial pain should consider screening routinely for psychosocial yellow flags. Such screening may be useful in identifying modifiable factors (for example, depression, drug abuse) that may affect adherence to the treatment regimen and short- and long-term outcomes, as well as in planning the treatment most appropriate and likely to succeed for a given patient.

Yellow flags. The following yellow flags are indicators that psychosocial factors may be important in a pain problem:

– disability (in daily work, household maintenance, recreational and social activities) out of proportion to objective findings;

– symptoms of psychological disorders (most commonly, depression, anxiety, somatization);

– prolonged or excessive use of opiates, benzodiazepines, alcohol or other drugs.

How to screen for yellow flags. Dentists who treat patients with chronic orofacial pain may find that asking them to complete a questionnaire before the initial evaluation can facilitate a comprehensive assessment. This is an efficient way to gather information about important sociodemo-graphic factors (for example, age, education, marital status), symptoms (nature, location, intensity, duration, exacerbating and relieving factors), physical and mental health, stressors (for example, job or family stress) and alcohol and prescription and nonprescription substance use.

Incorporation of standardized measures of pain intensity, disability and psychological symptom severity into the questionnaire enables the clinician to screen for high levels of these characteristics, a critical first step in making treatment decisions. A review of the patient’s responses to the questionnaire during the initial visit can serve as a springboard for discussion and clarification of psychosocial problems. The goal is not to make a psychiatric diagnosis, but rather to screen for indicators that point to a need for referral to a psychologist or psychiatrist.

Valid and reliable measures of yellow flags. We identified multiple valid and reliable self-report measures^19–33 that can be used by a dentist to screen for each of the psychosocial risk factors described above (Box). Published criteria exist for each of these measures that enable clinicians to categorize patients into groups based on levels of the characteristic (for example, moderate or severe disability or depressive symptoms).

Approximately 10 percent of adults receiving treatment in primary care settings have a depressive disorder.

Disability. To screen for high levels of disability, a dentist may wish to consider using one of two measures that have been studied with patients with TMD: the Graded Chronic Pain Scale, or GCPS,^19,20 and the Multidimensional Pain Inventory, or MPI.²² The shorter of these two measures, the GCPS, was developed to provide a brief and simple method of grading the severity of chronic or recurrent pain. It has good validity and reliability, as assessed in samples of patients with headache and with TMD pain.^19,20 Patients are asked to rate their average, worst and current pain intensity on 0 to 10 scales; the mean of these three ratings is the characteristic pain intensity score.^19,20,34

Patients also are asked to rate on 0 to 10 scales the degree to which the pain interferes with daily activities, work/housework activities and recreational/social activities. The mean of these three ratings is the pain-related disability score.²⁰ In addition, clinicians can use the GCPS to classify patients into one of five categories:

– 0 = no pain;

– I = low pain intensity and low pain–related disability;

– II = high pain intensity and low pain–related disability;

– III = moderate pain–related disability;

– IV = severe pain–related disability.

The MPI assesses pain impact (severity, interference), responses of others (for example, solicitous, punishing) and activities, and enables patients to be classified into dysfunctional, interpersonally distressed and adaptive-coper subgroups. Such categorization may be useful for treatment planning. In one study, dysfunctional patients’ conditions improved more when treatment for depression was added to standard appliance and biofeedback therapy.³⁵ Epker and Gatchel³⁶ reported that dysfunctional and distressed patients with acute TMD were more likely to develop chronic TMD, and Dahlstrom and colleagues³⁷ reported that the dysfunctional profile predicted treatment failure.

Psychological disorders and substance use. Depression, somatization and anxiety are prevalent among patients with chronic pain who are treated in specialty clinics. For several reasons, we recommend that dentists screen all patients with chronic pain—even in primary care settings—for depression. First, depression is a common mental health disorder. Approximately 10 percent of adults receiving treatment in primary care settings have a depressive disorder,³⁸ and the prevalence rises with the care-setting level (from primary to tertiary).³⁹ The risk of depression increases substantially for patients with chronic pain.³⁹

Second, depression is a highly disabling condition. Major depression was the fourth leading cause of disability worldwide in 1990, and soon will be second only to heart disease.⁴⁰

Finally, depression is highly treatable. Unfortunately, however, depression is frequently unrecognized by health care providers; Cassano and Fava³⁸ reported that the diagnosis was missed in about half of the depressed patients treated in primary care settings. Any one of several self-report measures can be used to screen for depression (Box). The self-report measures are similar in their ability to detect depression⁴¹; the choice of measure depends on the brevity needed and the purpose (for example, screening only versus outcome monitoring) in the specific setting.

Clinicians should be alert to indicators of suicidal ideation (a red flag, indicating the need for immediate assessment) in patients’ responses on the self-report measures or in oral statements, because suicidal ideation is not uncommon in populations with chronic pain, and chronic pain may be a risk factor for suicide.⁴² The surgeon general has recommended that all health care providers receive training in assessment and recognition of suicide risk.⁴³ By referring a depressed or suicidal patient for further assessment and treatment, dentists may be providing a life-saving intervention.

No evidence exists to suggest that asking about depression or suicidal thoughts precipitates depression or suicidal thinking or acts. One way to approach patients who report a high level of depressive symptoms or thoughts indicative of possible suicidality is to express concern and ask if they have been feeling that life is not worth living. If the patient acknowledges such thoughts, follow-up questions might be, "Have you had thoughts that you would be better off dead?" and "Have you had thoughts of harming yourself?"

Clinicians should be alert to indicators of suicidal ideation in patients’ responses on the self-report measures or in oral statements.

Refer patients to a mental health professional. Clinicians should refer patients who answer "yes" to a mental health professional or psychiatric emergency facility for assessment; patients at imminent risk (for example, patients who have a plan for harming themselves or who will not say that they would not harm themselves) should be evaluated emergently. Risk factors for suicide include depression and other mental disorders, medical illness, hopelessness, substance abuse and previous suicide attempts.⁴³

Dentists may screen for alcohol abuse or dependence using the three-item Alcohol Use Disorders Identification Test, which has been shown to have good sensitivity and specificity.³⁰ A brief screen for both alcohol and drug abuse, with good sensitivity and specificity is the two-item conjoint screening test.^31,32 In addition, dentists may screen for alcohol problems, common mental disorders and psychosocial stress using a brief, self-administered questionnaire, the Primary Care Evaluation of Mental Disorders Patient Health Questionnaire, or PRIME-MD PHQ.³³

Screen for eight mental disorders. In less than three minutes, a clinician can scan the completed questionnaire and apply diagnostic algorithms to screen for eight mental disorders (Box). Good agreement has been shown between PHQ diagnoses and those of mental health professionals.³³ The clinician can use a three-page diagnostic portion of the PHQ to screen for all eight disorders; a four-page instrument that also includes questions about menstruation, pregnancy and childbirth, as well as recent psychosocial stressors; a two-page version (Brief PHQ) that covers mood, panic and somatoform disorders; or the first page only, which screens for mood and panic disorders.

Dentists who desire a single instrument that includes validated measures of pain and pain-related disability (the GCPS, described above and in the box) as well as measures of depression and somatization (see the box for symptom checklist scales) might consider the Research Diagnostic Criteria/ Temporomandibular Disorders, or RDC/TMD, Axis II.²¹ Several studies have demonstrated the clinical utility of the RDC/TMD Axis II. The depression scale of this instrument has been shown to be useful as a screen for depression among patients with TMD.²⁴ Furthermore, higher pain intensity, disability, depression and somatization scores at the initial assessment of patients with acute TMD predicted chronicity six months later.⁴⁴

Finally, because patients with TMD who have higher somatization scores have been found to have more muscle sites painful to palpation during the clinical examination,²⁴ knowledge of the patient’s somatization score may aid in interpreting the clinical examination findings. The RDC/TMD Axis II findings may be useful in tailoring treatments, regardless of the physical TMD diagnosis.^8,45 Patients who are classified as having moderate or severe disability probably will need multidisciplinary treatment aimed at reducing psychological and role dysfunction. The RDC/TMD does not include measures of alcohol or substance abuse, or of psychological disorders other than depression and somatization.

Obstacles to screening for yellow flags. Obstacles to screening for psychosocial risk factors in dental practices include lack of time, fear of opening a can of worms, discomfort in asking about sensitive issues and no one to whom patients can be referred for further assessment and therapy. Use of a questionnaire can be an efficient means of screening patients, and clinicians should keep in mind that screening can and often does take place over multiple visits.

Often, patients are much more willing to discuss personal issues with dentists after a relationship has been established; similarly, dentists may feel more comfortable delaying their inquiries until the second or third appointment, by which time the dentist-patient relationship typically is more open and trusting. Dentist discomfort in asking about personal and sensitive issues may be reduced further with education (knowing what to ask and how to ask, knowing how to respond and set limits) and experience. Finally, it is important for dentists to identify local resources (psychologists and psychiatrists who specialize in the assessment and treatment of patients with chronic pain) and to develop relationships with these professionals.

Referring patients to a psychologist or psychiatrist. When one or more yellow flags (and/or a red flag) is present and discussion with the patient confirms a likely psychosocial contributor to symptoms and dysfunction, the dentist should refer the patient to a psychologist or psychiatrist experienced in working with such patients. Patients often are concerned that such a referral implies that the dentist believes that their pain is not real or that they have a mental disorder. In addition, patients may not see the relevance of the referral to their pain problem, which they view as having a biological basis.

To reduce possible patient defensiveness and enhance receptiveness, dentists should carefully explain the reasons for the referral. The dentist should state explicitly that the referral is recommended not because he or she thinks the pain is caused by psychological factors, but because it may be helpful in reversing the negative impact of pain on the patient’s quality of life and ability to participate in customary activities. This can be illustrated by referring to symptoms the patient has reported (for example, depression, decreased activities) and stating that such problems frequently are associated with chronic pain, and can worsen the pain and suffering, thus creating a vicious cycle. In addition, it may be helpful to emphasize that treatments are available to improve these symptoms.

	CONCLUSIONS

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Substantial evidence exists that psychosocial dysfunction is prevalent among patients with chronic orofacial pain, most commonly TMD. Psychosocial yellow flags indicate an increased risk of failure of standard treatments, and matching patients to treatments based on these risk factors may optimize treatment outcomes. Yellow flags can be identified via reliable and valid screening instruments. Dentists may improve the quality of care provided to patients with oro-facial pain through the routine use of such measures, and by referring patients with psychosocial risk factors to a psychologist or psychiatrist with expertise in assessing and treating patients who have chronic pain.