Fibromyalgia and Psychologic Status
PSYCHOLOGIC STATUS
Emotional distress is one of the core components of FMS. The search for a defined psychiatric disorder as a cause or trigger for FMS has been disappointing. Nevertheless, depression may follow chronic pain as a secondary phenomenon. Instruments designed to identify this treatable condition are important to the overall assessment of the FMS patient. On the other hand, there have been numerous abnormalities in a variety of other psychologic instruments that examine a wide range of patient characteristics. Although no one instrument seems useful in its own right, those that measure patients' beliefs, attitudes, and stress reactivity appear important in assembling information that might contribute to a management program or study of the pathogenesis of the disorder. Currently, no one single instrument appears to capture a global psychologic summary of FMS patients (Table 3).
General Psychopathology
A number of instruments may detect general psychologic distress in
FMS patients. The Minnesota Multiphasic Personality Inventory (MMPI) .50.
has been commonly used for assessing personality characteristics of
chronic pain patients, including those with FMS. This is a 566-item true
false questionnaire that describes the patient on their validity and 10
clinical scales. The MMPI was validated in medically healthy
populations in persons over the age of 16 who could read English and
were of at least low-average intelligence. It suffers from cultural
biases for those not raised in the United States and does not
differentiate organic from nonorganic pain-related symptoms.
Interpretation of this instrument is based on scale elevations and
profile patterns. Scale values are based on standardized T-scores
derived from normative samples. In general, a standardized T-score over
70 is considered to be "elevated." T-scores are standardized to a mean
of 50. It has been noted that this measure is time-consuming, tedious,
and very psychologically orientated, but does have the advantage of
providing an extensive database regarding personality characteristics.100.
Chronic pain patients, including those with FMS, are
characterized by elevations of the hypochondriasis, depression, and
hysteria scales,80,91,106. which suggests somatic
preoccupation and concern, unhappiness, lack of psychologic insight, and
tendency to develop somatic symptoms in response to stress and internal
conflict. Further analysis of MMPI scores in FMS patients by
multivariate analysis indicates that one third of subjects are
psychologically disturbed; the others are normal or have typical chronic
pain profiles.106 Smythe.93. pointed out that
questions concerned with pain and somatic symptoms are positive in any
person with a chronic pain condition. He felt that there was a 40% bias
towards elevated scores on hypochondriasis, hysteria, and depression
scales, based solely on the presence of chronic pain in FMS patients.
Other studies.60. suggest a complex psychologic disturbance
in FMS, as physical illness alone appears unlikely to drive MMPl
profiles into the abnormal range.37 There have been few
studies correlating MMPI results with other characteristics of FMS
patients. Although the MMPl may be regarded as a "standard" measure of
psychologic aspects of chronic pain, its routine use in the assessment
of FMS patients, for the reasons just discussed, has not yet been
established. Some would indicate that a skilled interpreter can
eliminate the biases of the inventory in patients with FMS.37,100
.
Table 3. PSYCHOLOGICAL ASSESSMENT IN FIBROMYALGIA SYNDROME
Characteristic Instrument (examples)
General psychopathology Minnesota Multiphasic Personality Inventory (MMPI)
Symptom Check List-90 (SCL-90)
Brief Symptom Inventory (BSI)
Basic Personality Inventory
Diagnostic Interview Schedule (DIS)
Depression DIS
SCL-90 (BSI)
Profile of Mood States (POMS)
Visual Analog Scale (VAS)
Beck Depression Index
Zung Self-Rating Depression Scale
Hamilton Rating Scale
Centre for Epidemiology Studies Depression Scale
Face Scale
Arthritis Impact Measurement Scales (AIMS)
Anxiety POMS
SCL-90 (BSI)
Beck Anxiety Inventory
VAS
DIS
Speilberger State-Trait Anxiety Inventory
AIMS
Stress Family Inventory of Life-Events
Holmes-Rahe Life Events Inventory
Daily Hassles Scale
Beliefs, Attitudes Multidimensional Health Locus of Control
Perceived Threat
Learned Helplessness
Fibromyalgia Attitudes Index
Pain Beliefs and Perceptions Inventory
Survey of Pain Attitudes
Social Skills,
Motivation Bakker Assertiveness Aggressive Scale
Self-Motivation Scale
Coping Strategies Questionnaire
In contrast to the MMPI, an empirically derived scale, the SCL-90 is a subjective face-validity constructed personality scale.33 This 90-item self-report symptom inventory is designed to measure psychologic symptom patterns of both psychiatric and medical patients. Each item is rated on a five-point scale of severity and nine symptom dimensions (including depression, anxiety, and hostility, for example), and three global indices of distress are scored. Scale scores are compared with normative samples and values expressed as T-scores and are graphed to yield a profile of symptom patterns. This questionnaire is considerably shorter than the MMPI and yields a numerical index of the degree of physiologic distress. Clark.29. found no significant difference between FMS patients and healthy controls using this methodology, although selection biases may have led to this result. The Brief Symptom Inventory (BSI) is a 53-item self-report screening instrument developed as a shortened version of the SCL-90." It also provides an index of psychologic distress in addition to multi-dimensional symptom measurement. Normative data using community nonpatient normal samples is available.
The Basic Personality ]Inventory (BPI) has shown FMS patients to have significantly higher scores in four of the scales (hypochondriasis, depression, anxiety, and social introversion). A high degree of classification accuracy is achieved with these scores compared to rheumatoid arthritis and normal controls.91.
It has been suggested that structured psychiatric interviews, such as the Diagnostic structured Interview (DIS)," are more likely to provide a valid psychiatric diagnosis according to standardized diagnostic criteria. These include the Diagnostic and Statistical Manual of Mental Disorders (DSM-Ill-R) .7.and the 10th Revision of the International Classification of Diseases (ICD-lO).9. The DSM-111-R criteria provide for definitions of a wide range of psychiatric disorders, including major affective disorders, anxiety disorders, substance abuse disorders, psychotic disorders, somatization disorders, and antisocial personality disorders. Using this technique, increased past and current diagnosis of major depression, anxiety, or somatization disorder, for instance, may be studied in patients with FMS. 5,42,52.
