J. psychiot. Res., Vol. 24, No. 4, pp. 323-334,

Printedin GreatBritain.

0022-395600 $3.00+ .Gll 0 1991Pergamon Pressplc

1990.

THE SOMATOSENSORY

AMPLIFICATION

RELATIONSHIP ARTHUR

J. BARSKY,

I GRACE

SCALE AND ITS

TO HYPOCHONDRIASIS WYSHAK~

and

GERALD

L.

KLERMAN~

‘Department of Psychiatry, Harvard Medical School; Psychiatry Service and Primary Care Program, Massachusetts General Hospital, A.C.C. 807, Fruit Street, Boston, MA 02114, U.S.A.; ‘Department of Medicine, Harvard Medical School; Department of Biostatistics, Harvard School of Public Health; Center for Population Studies, Harvard School of Public Health, Boston, MA, U.S.A.; and 3Department of Psychiatry, Cornell University Medical College, New York, NY, U.S.A. (Received 9 April 1990; revised 8 August 1990) Summary-Forty-one DSM-III-R hypochondriacs and seventy-five randomly chosen patients were obtained from a medical outpatient clinic, and completed a psychiatric diagnostic interview and a ten-item self-report questionnaire, the Somatosensory Amplification Scale (SSAS); The SSAS asks the respondent how much s/he is bothered by various uncomfortable visceral and somatic sensations, most of which are not the pathological symptoms of serious diseases. SSAS scores were normally distributed, and had acceptable test-retest reliability and internal consistency. They were not related to sociodemographic characteristics, or to aggregate medical morbidity. Amplification was significantly higher in the DSM-III-R hypochondriacs than in the comparison sample, and was significantly correlated with the degree of hypochondriacal symptomatology within each sample. In the comparisonsample, it was also significantly associated with depressive and anxiety disorders, but not with antisocial personality or substance abuse. The association between the amplification scale and DSM-III-R hypochondriasis remained highly significant after controlling for these concurrent psychiatric disorders.

Introduction symptoms can be thought of as the product of psychodynamic forces, interpersonal miscommunication, formative learning experiences, or an amplifying cognitive and perceptual style. In a previous paper, we reviewed the criteria for the clinical diagnosis of hypochondriasis and discussed these possible mechanisms of pathogenesis (Barsky & Klerman, 1983). In this paper, we explore the possible role of perceptual amplification. Somatosensory amplification refers to a tendency to experience somatic and visceral sensation as unusually intense, noxious, and disturbing. It involves bodily hypervigilance, the predisposition to focus on certain weak and infrequent bodily sensations, and a tendency to appraise them as pathological and symptomatic of disease, rather than normalizing them. The DSM-III-R description of hypochondriasis emphasizes the faulty “interpretation of physical signs and sensations as evidence of physical illness” (Diagnostic & Statistical Manual of Mental Disorders, 1987). But this bit of clinical description is not among the diagnostic criteria, and its actual presence in patients meeting those criteria has not been tested empirically. Thus the hypochondriac is thought to amplify normal physiological sensations, the somatic concomitants of intense affect, and the benign symptoms of trivial and self-limited infirmities (e.g., tinnitis, a twitching eyelid). Because his/her symptoms are so intense, the hypochondriac mistakenly concludes that they are abnormal and HYPOCHONDRIACAL

323

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et al.

pathological, rather than normalizing them by attributing them to a more benign cause such as overwork, insufficient rest, inadequate exercise, or dietary indiscretion. A headache, for example, is attributed to a brain tumor rather than to “eyestrain”. Believing now that he is sick, the hypochondriac scrutinizes his body further for additional symptoms. He filters his somatic perceptions, selectively attending to those that confirm his hypothesis, while ignoring sensory input that does not confirm it (Pennbaker, 1982; Leventhal, Meyer, & Nerenz, 1980). As a result he now becomes aware of new (benign) symptoms, and these are incorrectly ascribed to the presumed disease. In addition, mounting anxiety itself generates autonomic symptoms, and these new symptoms are further cause for alarm. Empiric investigation of visceral and somatic amplification is relatively sparse (Raine, Mitchell & Venables, 1981). Work has been done using kinesthetic, visual, auditory, pain, and somatosensory stimuli (Petrie, 1978; Buchsbaum, 1976; Buchsbaum & Silverman, 1978; Gordon, Kraiuhin, Meares, & Howson, 1986; Hanback & Revelle, 1978). Tasks of size and weight estimation have been administered to assess kinesthetic amplification (Petrie, 1978), and dual flicker fusion of light used to measure visual sensitivity (Hanback & Revelle, 1978). Cortical potentials evoked by experimental pain have been studied, and there has been extensive work on pain tolerance and thresholds (Buchsbaum, 1975, 1978). There has also been an interest in self-report measures of visceral sensitivity and reactivity. Questionnaires such as the Autonomic Perception Questionnaire (Mandler, Mandler, & Uviller, 1958), the Modified Somatic Perception Questionnaire (Main, 1983), and the Perceived Somatic Response Inventory (Meadow, Kochevar, Tellegen, & Roberts, 1978) have been developed. In the aggregate, this work suggests that amplification is associated with the reporting of more bodily symptoms (Pennebaker, 1982; Meadow et al., 1978; Mechanic, 1980), heightened sensitivity to pain (Petrie, 1978; Buchsbaum, 1978; Main, 1983), and with introspectiveness and increased self-awareness (Pennebaker, 1982; Mechanic, 1983; Miller, Murphy, & Buss, 1981; Fenigstein, Scheier, & Buss, 1975). Direct measures of perceptual reactivity are cumbersome, elaborate and time-consuming to administer, and adequate reliability is difficult to achieve and requires many trials. They are therefore not feasible for use in clinical settings. Self-report questionnaires, on the other hand, raise serious questions of validity and have not found broad acceptance or utility. Such self-report instruments have focused on the somatic symptoms of autonomic nervous arousal and on bodily sensations that are obviously pathological (e.g., pain). Because we hypothesized that hypochondriacs are unduly disturbed by normal bodily sensations, a self-report questionnaire would necessarily have to assess the respondent’s sensitivity to mild bodily experiences which are uncomfortable and unpleasant but which are not typical symptoms of disease. We began by generating a large-item pool of uncomfortable but benign sensations volunteered by somatizing medical outpatients who were asked what sorts of bodily discomforts they noticed. We then eliminated items which were ambiguous, redundant, or unreliable. A five-item scale, the Somatosensory Amplification Scale (SSAS) was derived and then employed in two studies (Barsky, Goodson, Lane, & Cleary, 1988; Barsky & Wyshak, 1990). It was found to have a testretest reliability of 0.85 (coefficient of reproducibility) and an internal consistency of 0.70 (Cronbach’s alpha). The SSAS was significantly correlated with a self-report measure

SOMATOSENSORY AMPLIFICATION SCALE

325

of hypochondriacal symptoms in a random sample of primary care patients (Barsky & Wyshak, 1990), and was also correlated with discomfort and the intensity of local symptoms experienced by patients with upper respiratory tract infections (Barsky et al., 1988). In this paper we present the psychometric characteristics of an expanded, ten-item version of the SSAS. We also examine the possible role of amplification, as measured by this scale, in DSM-III-R hypochondriasis. Methods Setting and Subjects The study was conducted in the general medicine clinic of the Massachusetts General Hospital. The clinic serves 29,000 patients, who make over 50,000 visits annually. It is staffed by 36 attending physicians. Patients were eligible if they had been followed at the hospital for at least 24 months and had had at least one prior visit to the same primary physician. The exclusion criteria were inability to speak English and major sensory or communication deficits. Design and Procedure Consecutive clinic attenders on randomly chosen days were given a screening questionnaire for hypochondriasis. The screening questionnaire consisted of the Whiteley Index and the Somatic Symptom Inventory (discussed in the following section). Those scoring above a predetermined cut-off, and a random sample of those scoring below, returned to undergo the research battery. This consisted of self-report questionnaires (including the SSAS), and structured and semi-structured interviews. Also included was a structured diagnostic interview for hypochondriasis, which served as the criterion standard for diagnosing DSMIII-R hypochondriasis. The battery was administered by a research assistant who did not know the patient’s screening score. The patients’ medical records were audited and their clinic physicians completed a questionnaire about them. The subjects then completed the amplification questionnaire again by mail l-6 weeks later. Informed consent was obtained after explaining the study. Subjects received $40 for their participation. Variables and Their h4easurement The Somatosensory Amplification Scale (SSAS) asks the respondent the degree to which 10 statements are “characteristic of you in general”, on an ordinal scale from 1 to 5. The items cover a range of uncomfortable bodily sensations, most of which generally do not connote serious disease. Two of the items (“hunger contractions” and “various things happening in my body”) are similar to items in Miller’s Body Consciousness Questionnaire (Miller, Murphy, & Buss, 1981). The clinical diagnosis of hypochrondriasis was made with a structured diagnostic interview based on DSM-III-R criteria. This interview has acceptable inter-rater reliability and convergent and predictive validity (the subject of a separate report; data available on request). Hypochondriacal symptoms were assessed with the Whiteley Index and the Somatic Symptom Inventory (SSI). The Whiteley Index consists of 14 items which compose three

326

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J. BARSKY

et al.

subscales: disease fear, disease conviction, and bodily preoccupation. Its test-retest reliability, internal consistency, and discriminant and convergent validity have been established (Pilowsky, 1967, 1978). One Whiteley Index item which is similar to an SSI item (bodily awareness) was eliminated, in order to obviate the possibility of covariance. In this study the intra-scale consistency of the thirteen-item Whiteley Index was 0.85 (Cronbach’s alpha) and its test-retest reliability was 0.84 (Pearson product moment correlation). Hypochondrical somatic symptoms were assessed with the SSI, a twenty-sixitem questionnaire drawn from the MMPI hypochondriasis subscale and the Hopkins Symptom Check List-90 somatization subscale (Derogatis et al., 1981; Lipman, Covi, & Shapiro, 1977). In this study, its test-retest reliability was 0.86 and its intra-scale consistency was 0.95 (Cronbach’s alpha). In previous work, the Whiteley Index and SSI were highly inter-correlated and together identified medical outpatients with a syndrome consistent with DSM-III hypochondriasis (Barsky, Wyshak, & Klerman, 1986). Psychiatric morbidity was assessed with the Diagnostic Interview Schedule (DIS), version III-A. This highly structured diagnostic interview has been widely employed in recent research to generate criterion standard psychiatric diagnoses in conformity with DMS-III nosology (Robins, Helzer, Croughan, & Ratcliff, 1981). It generates most of the major Axis I disorders, both current and lifetime. Somatization Disorder is the only somatoform disorder included in the DIS. For all analyses, psychosexual dysfunction, post-traumatic stress disorder, and tobacco dependence were omitted. Personality disorder was assessed with the five-item impairment/distress subscale of the Personality Diagnostic Questionnaire (Hyler, Rieder, Spitzer, & Williams, 1987): Hyler et al., 1990). This subscale correlates 0.75 with the total score on the complete PDQ, and has been used to predict personality disorder “caseness”. Disability was assessed with the Functional Status Questionnaire (FSQ), a valid and reliable self-report instrument developed for use in ambulatory medical populations (Jette et al., 1986). We employed the 31 items which compose 4 out of its 6 subscales: basic activities of daily living, intermediate activities, social activities, and work performance. The FSQ is scored by computer, which provides numerical ratings from 1 to 100 (maximal function). Medical morbidity was assessed in two ways (r = 0.66; p = .OOOl). Firstly, the patient’s medical record was audited and the degree of seriousness of every medical diagnosis was rated according to explicit predetermined criteria. This method was demonstrated to have adequate inter-rater reliability. Secondly, the patient’s physician rated current aggregate morbidity and future prognosis on a five-point ordinal scale. Statistical Methods Statistical analyses include t-tests and analysis of variance and covariance for continuous and ordinal data; chi square for categorical data. Zero-order Pearson correlations were computed for determining the association between two variables; multiple regression was used to determine the association between an outcome variable and two or more predictor variables. Stepwise regression with a 0.15 level for inclusion, and covariance analyses using the General Linear Model procedure were used to account for potential confounding and explanatory factors. Analyses were done using SAS for PCs. Significance values are p 5 .05 (two-tailed).

SOMATOSENSORYAMPLIFICATION SCALE

321

Results One thousand, nine hundred and thirty-eight patients were approached to participate in the study. One thousand and thirty-six (53.5 % of them) consented, met inclusion criteria, and completed the screening questionnaires. Ninety-two of these (8.9%) exceeded a predetermined cut-off score on the hypochondriasis screening questionnaire; sixty-three of these (68.5 Vo)could be contacted and consented to undergo the research battery. Fortyone (69.1 C7o)were diagnosed as having DSM-III-R hypochondriasis with the diagnostic interview. They constitute the hypochondriacal sample. One hundred and forty-six patients were selected at random from among those below the cut-off on the screen, and seventyfive of them (53.6%) could be contacted and were willing to complete the battery. None was diagnosed as hypochondriacal using the diagnostic interview. They constitute the comparison sample. The mean age of the hypochondriacal sample was 57.1 (SD f 15.6), and 76% were female. Seventeen per cent were in social classes 1 (highest) and 2, 32 % in class 3, and 5 1% in classes 4 and 5 (lowest), using the Hollingshead and Redlich Index of Social Position (Hollingshead & Redlich, 1958). Fifty-one per cent were married. The comparison sample did not differ significantly on any of these parameters, except that fewer (5.3 vs. 17.1 Vo) were Black (OR = 3.65; 95 Vo CI = 1.06-12.58; p = .04). This difference remained significant after controlling for socioeconomic status and medical morbidity. The Somatosensory Amplification Scale was normally distributed in both samples, and was not significantly correlated with any sociodemographic characteristic. Test-retest reliability over a median interval of 74 days was 0.79 (p = .OOOl), and the internal consistency was 0.82 (Cronbach’s alpha). The item-to-scale and item-to-item correlations and test-retest data are presented in Tables 1 and 2: item-to-item correlations varied from 0.66 to 0.31, and all were highly significant; item-to-item correlations varied from 0.60 to nonsignificant, but most were in the range of 0.35 and were highly significant. Table

1

Psychometric Characteristics of Somatosensory Amplification

Mean

Standard deviation

r

P

,

too

1.16

0.47

0.37

,001

0.30

.080

in the air

2.44

1.29

0.55

.OOOl

0.79

.OOOl

2.07

1.12

0.50

.OOOl

0.50

.0026

2.11

1.27

0.62

.OOOl

0.72

.OOOl

1.33

0.79

0.31

,007

0.65

.OOOl

2.23

1.32

0.64

.OOOl

0.68

.OOOl

1.73

0.98

0.56

.OOOl

0.43

.OlO

2.91

1.24

0.66

.OOOl

0.39

.022

2.30

1.08

0.39

.0005

0.65

.OOOl

1.57

1.00

0.57

.OOOl

0.59

.0002

Item

1. When someone 2. I can’t

stand

else coughs, smoke,

3. I am often aware my body 4. When 5. Sudden

I bruise

smog,

of various

myself,

it makes things

happening

it stays noticeable

loud noises really bother

6. I can sometimes in my ear

me cough

or pollutants

for a long time

me

hear my pulse or my heartbeat

I am quick to sense the hunger contractions

9. Even something minor, really bothers me 10. I have a low tolerance

Item-to-scale correlation

Test-retest reliability

P

within

throbbing

7. I hate to be too hot or too cold 8.

Scale Comparison Sample (n = 75j

in my stomach

like an insect bite or a splinter, for pain

Table 2

aPearson

Correlation

Coefficients

.03 NS

.21 ,037

9. Even something minor, like an insect bite or a splinter, really bothers me for pain

.lO NS

8. 1 am quick to sense the hunger contractions in my stomach

I have a low tolerance

.12 NS

7. I hate to be too hot or too cold

10.

.29 .0042

6. I can sometimes hear my pulse or my heartbeat throbbing in my ear

me .I8 NS

loud noises really bother

5. Sudden

.30 .0023

.29 .0043

1.0 ,000

.14 NS

things

or

it makes

1

4. When I bruise myself, it stays noticeable for a long time

3. I am often aware of various happening within my body

smog,

else coughs,

2. I can’t stand smoke, pollutants in the air

1. When someone me cough too

Intercorrelations Among SSAS Items”

.07 NS

.32 .0013

.29 .0042

.34 .0006

.32 .OOll

.39 .OOOl

.32 .0014

.30 .0026

1.0 ,000

2

3

.26 .0102

.36 .0003

.37 .0002

.27 .0074

.33 .0009

.I4 NS

.32 .0015

.41 .OOOl

.24 .0169

.38 .OOOl

.26 .0085

.26 .0094

1 .o ,000

4

N = 116

.36 .0003

1.0 .OO

All Subjects,

.48 .OOOl

.51 .OOOl

.25 .0118

.43 .OOOl

.19 NS

1.0 .OOO

5

.12 NS

.33 .0009

.38 .OOOl

.38 .OOOl

1.0 ,000

6

.32 .0013

.51 .OOOl

.45 .OOOl

1.0 ,000

7

.25 .0125

.34 .0006

1.o ,000

8

.60 .OOOl

1.0 ,000

9

1.0 .OOO

10

329

SOMATOSENSORY AMPLIFICATION SCALE

The mean SSAS score was higher in DSM-III-R hypochondriacs than in the comparison patients: 2.78 (SD = 0.67) vs. 1.98 (SD = 0.58); p < .OOl. The relationship between amplification and hypochondriacal symptoms is explored in Table 3. In the random sample, i.e., among patients who are not clinically hypochondriacal, amplification is highly correlated with hypochondriacal symptoms, particularly bodily preoccupation. Within the sample of DSM-III-R hypochondriacs, the correlations are somewhat weaker, and fail to reach significance for disease conviction and somatic complaints. Among the somatic complaints, fatigue (r = 0.53; p = .OOOl)and weakness (r = 0.47; p = .OOOl)are most closely correlated with amplification. Chest pain and headaches were the weakest correlates. Table 3

Correlations of Somatosensory Amplification

Scale and Hypochondriacal Symptoms

Comparison sample n = 15

Amplification and hypochondria& (Whiteley Index) Amplification and disease conviction Amplification and disease fear Amplification and bodily preoccupation Amplification and somatization (Somatic Symptom Inventory)

Hypochondriacal n =41

sample

r

P

r

0.60

.OOOl

0.43

,005

0.43

.OOOl

0.15

NS

0.51

.OOOl

0.35

.023

0.54

.OOOl

0.58

.OOOl

0.44

.OOOl

0.20

NS

P

Table 4

Multiple Stepwise Regression, Correlates of Hypochondriacal Symptoms Step

Partial

Variable

Comparison

sample

Amplification (SSAS) Physician-rated hypochondriasis Disability Patient-rated global health status (inverse) Race Physician-rated effectiveness of care (inverse) Total psychopathological symptoms (DIS) F 7,6, = 15.02; p = .OOOl sample

.318 ,142 .072 .030 .039 .019 .013

.318 .459 .532 .561 .600 .620 .633

.I85 ,102 .076 .060 .091

.185 .288 .364 ,423 ,515

(n = 41)

1. 2. 3. 4. 5.

Amplification (SSAS) Age Patient-rated global health status Physician-rated hypochondriasis Sex F 5,35= 8.48; p = .OOOl

Note. Dependent

Model R2

(n = 75)

1. 2. 3. 4. 5. 6. 7.

Hypochondriacal

R2

variable:

Whiteley

(inverse)

Index Score.

A. J.

330

BARSKY

et al.

Multiple stepwise regressions were performed (Table 4) using the Whiteley Index score as the dependent variable, and as independent variables the SSAS score, sociodemographic descriptors, medical morbidity, aggregate psychopathology, personality disorder caseness, functional status, patient-rated global health status, and ratings of the effectiveness of care by patient and doctor. In the comparison (nonhypochondriacal) sample, amplification enters the equation first (RI = 0.318). A seven step regression, including physician ratings of hypochondriasis, disability, and perceived global health status, attains a total R’ of 0.633. In the hypochondrical sample, the SSAS score again enters the equation first, accounting for 18.5% of the variance. A five step equation, including age, sex (females being more hypochondriacal), patient-rated health status, and physician-rated hypochondriasis, explains 5 1.5% of the variance. Table 5 Correlates

of Somatosensory

Amplification

Scale’ Comparison sample n = 75 P

Total number of psychopathological symptoms (DIS Number of psychiatric diagnoses (DE) Personality disorder caseness (PDQ) Depressive disorders (major depression, dysthymia, and bereavement) Anxiety disorders (generalized anxiety disorder, panic disorder, and phobia) Alcohol and substance abuse and dependence Antisocial personality Somatization disorder symptoms (DIS) Medical morbidity aPearson

Correlation

Hypochondriacal n = 41 r

sample

P

0.42

.OOOl

0.32

.04

0.35 0.34 0.38

,002 ,002 .0007

0.27 0.28 0.16

NS NS

0.46

.OOOl

0.22

NS

0.20

NS

0.10

NS

0.13 0.33 0. I8

NS ,004 NS

0.16 0.29 -0.1 I

NS NS NS

NS

Coefficients.

Table 5 presents the relationships between amplification and several measures of psychiatric disorder. In the comparison group, amplification is significantly correlated with aggregate psychiatric morbidity, and with depressive, anxiety, and somatization disorder. It is not associated with antisocial personality or substance abuse. Among DSM-III-R hypochondriacs, none of these relationships is significant, with the exception of a modest correlation between amplification and the total number of psychopathological symptoms (DIS interview). Since amplification was found to be associated with anxiety and depressive disorders as well as hypochondriasis, this could confound the univariate association between hypochondriasis and amplification. An analysis of covariance was therefore performed, controlling for psychiatric co-morbidity. The relationship between amplification and DSMIII-R hypochondriasis remained highly significant. The SSAS mean, adjusted for the total number of DIS diagnoses, is 2.67 in the hypochondriacal sample and 2.04 in the comparison

SOMATOSENSORY AMPLIFICATION SCALE

331

sample @ = .008). When adjusted for the presence of anxiety and depressive disorders, the SSAS mean is 2.54 in the hypochondriacal sample and 1.98 in the comparison group @ = .OOl). Medical morbidity is also a possible confounder of the relationship between amplification and hypochondriasis, since medical illness might sensitize one to somatic sensation and foster bodily scrutiny. The SSAS, however, was unrelated to aggregate medical morbidity, whether measured with physician ratings or with a medical record audit. Discussion The SSAS asks the respondent about his/her perceived sensitivity to several unpleasant bodily sensations, most of which to not connote disease. It has adequate internal consistency and test-retest reliability, suggesting that amplification may be a unitary construct with at least some degree of stability over time. The amplification scores of DSM-III-R hypochondriacs are significantly higher (2.78 vs. 1.98; p < .OOl) than those of the nonhypochondriacal patients in the same ambulatory medical setting. In both univariate and multivariate analyses, amplification is significantly associated with three different measures of hypochondriasis-a self-report symptom inventory, the DSM-III-R diagnosis, and primary physician ratings of hypochondriasis. Among the hypochondriacal symptoms, bodily preoccupation is most closely associated with amplification. The SSAS is associated with anxiety and depressive disorders, but not with antisocial personality or alcohol or substance abuse, in the comparison sample. Although the same trend appears in the sample of hypochondriacs, it does not reach statistical significance. This suggests some degree of discriminant validity, since it is the psychiatric disorders not typically characterized by somatic symptoms which are not associated with higher SSAS scores. The association of the SSAS with hypochondriasis appears to be more specific and more powerful than with other psychiatric disorders, since it persists after controlling statistically for other concurrent psychiatric morbidity. Our findings are therefore consistent with the hypothesis that hypochondriasis involves a heightened sensitivity to benign bodily dysfunction and normal physiology. Although the SSAS and Whiteley Index appear to be closely related in this population, and to measure overlapping characteristics, they are not intended to tap the same theoretical construct. The Whiteley Index inquires into attitudes, concerns, beliefs, and fears about health and disease while the SSAS asks about bodily distress-the discomfort associated with bodily sensations. A similar hypothesis has recently been advanced for the pathogenesis of panic disorder, in which it has been suggested that the panic attack results from the misinterpretation of sympathetic autonomic arousal as evidence of an impending medical catastrophe (Ottaviani & Beck, 1987; Clark, 1986). While we found an association between SSAS and anxiety disorders in general, there were too few cases of panic disorder to test for this specific association. The somatization disorder findings are interesting, since one might suspect amplification to be as salient in this disorder as in hypochondriasis. The correlation between amplification and the somatization disorder symptom count was less robust than that between amplification and hypochondriacal symptoms (r = 0.33 vs. r = 0.60). Amplification may thus be more closely related to hypochondriasis than to somatization disorder. This is

A.

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et

al

consistent with the recent finding that somatization disorder patients did not have higher auditory cortical evoked potentials than normals (Gordon et al., 1986). Amplification was unrelated to sociodemographic characteristics. Nor were SSAS scores related to aggregate medical morbidity. While we might expect that being sick heightens somatic vigilance and provides ominous explanations for normal bodily sensations, this does not appear to be the case; patients with more extensive medical histories did not have higher amplification scores. This study has several limitations. Firstly, we have not demonstrated the concurrent validity of the SSAS against a direct measure (rather than a self-report) of visceral or somatic sensitivity. This could be done with neurophysiological measures of the response to a visceral or somatic stimulus, or with measures of threshold and tolerance to an experimental stimulus. In this study however, we are dealing only with what people say they perceive and not with an objective, independent measure of what they perceive. Secondly, the crosssectional nature of this study does not permit any conclusions about the direction of causality between psychiatric disorder and somatosensory amplification; it is as likely that these disorders cause amplification as it is that preexisting amplification causes patients to notice their somatic symptoms more. Finally, the statistical associations found within the hypochondriacal sample are generally weaker than those with the comparison sample. This may be because the former group has such extremely high levels of hypochondriacal symptomatology that there is little inter-individual variability. Continuous associations with other variables are therefore difficult to demonstrate. In addition, the sample size is relatively small. The general association between disturbing physical symptoms (measured with the SSAS) and disturbing psychiatric symptoms (measured with the DIS) is not surprising in light The tendency to experience and report of the extensive literature on “negative affectivity”. a wide range of negative emotions has been termed negative affectivity or neuroticism, and has been shown to be an internally reliable, valid, and stable psychometric construct (Watson & Clark, 1984; Watson & Tellegen, 1985; Diener & Emmons, 1985). Individuals who score high on self-report questionnaires of negative affectivity in turn report high levels of many somatic symptoms as well (Diener & Emmons, 1985; Costa & McCrae, 1980, 1985). The current study, however, attempts to go beyond this general association between physical discomfort and psychological discomfort to explore a more specific relationship between nonpathological bodily sensation and hypochondriasis. It is therefore possible that the distress and discomfort that the hypochondriac feels with benign bodily sensation is only one facet of a more general propensity toward dissatisfaction with a wide range of life experiences. Hypochondriacs might be more querulous, fretful and fault-finding with regard to their finances, their marriages, and their jobs, for example. Future research should begin to examine the possibility of such trait-like characteristics in hypochondriasis. The SSAS is a potential tool for further investigation in this area. Its validity as a measure of sensitivity to nonpathological bodily sensation must now be established by comparing it with direct, objective measures of somatic and visceral perception. .4cknow/erlgemen/-This of Mental Health.

investigation

was supported

by research

grant

MH 40487 from the National

institute

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