An International Study of the Relation between Somatic Symptoms and Depression

Abstract

Patients with depression, particularly those seen by primary care physicians, may report somatic symptoms, such as headache, constipation, weakness, or back pain. Some previous studies have suggested that patients in non-Western countries are more likely to report somatic symptoms than are patients in Western countries. We used data from the World Health Organization's study of psychological problems in general health care to examine the relation between somatic symptoms and depression. The study, conducted in 1991 and 1992, screened 25,916 patients at 15 primary care centers in 14 countries on 5 continents. Of the patients in the original sample, 5447 underwent a structured assessment of depressive and somatoform disorders.
A total of 1146 patients (weighted prevalence, 10.1 percent) met the criteria for major depression. The range of patients with depression who reported only somatic symptoms was 45 to 95 percent (overall prevalence, 69 percent; P=0.002 for the comparison among centers). A somatic presentation was more common at centers where patients lacked an ongoing relationship with a primary care physician than at centers where most patients had a personal physician (odds ratio, 1.8; 95 percent confidence interval, 1.2 to 2.7). Half the depressed patients reported multiple unexplained somatic symptoms, and 11 percent denied psychological symptoms of depression on direct questioning. Neither of these proportions varied significantly among the centers. Although the overall prevalence of depressive symptoms varied markedly among the centers, the frequencies of psychological and physical symptoms were similar.
Somatic symptoms of depression are common in many countries, but their frequency varies depending on how somatization is defined. There is substantial variation in how frequently patients with depression present with strictly somatic symptoms. In part, this variation may reflect characteristics of physicians and health care systems, as well as cultural differences among patients.

Full text

Volume 341 Number 18
·
1329
The New England
Journal
of
Medicine
© Copyright, 1999, by the Massachusetts Medical Society
VOLUME 341
O
CTOBER
28, 1999
NUMBER 18
AN INTERNATIONAL STUDY OF THE RELATION BETWEEN SOMATIC SYMPTOMS
AND DEPRESSION
G
REGORY
E. S
IMON
, M.D., M.P.H., M
ICHAEL
V
ON
K
ORFF
, S
C
.D., M
ARCO
P
ICCINELLI
, P
H
.D., C
LAUDIO
F
ULLERTON
, M.D.,
AND
J
OHAN
O
RMEL
, P
H
.D.
A
BSTRACT
Background
Patients with depression, particular-
ly those seen by primary care physicians, may report
somatic symptoms, such as headache, constipation,
weakness, or back pain. Some previous studies have
suggested that patients in non-Western countries are
more likely to report somatic symptoms than are pa-
tients in Western countries.
Methods
We used data from the World Health Or-
ganization’s study of psychological problems in gener-
al health care to examine the relation between somat-
ic symptoms and depression. The study, conducted
in 1991 and 1992, screened 25,916 patients at 15 pri-
mary care centers in 14 countries on 5 continents. A
total of 5447 of the patients underwent a structured
assessment of depressive and somatoform disorders.
Results
A total of 1146 patients (weighted preva-
lence, 10.1 percent) met the criteria for major depres-
sion. The range of patients with depression who re-
ported only somatic symptoms was 45 to 95 percent
(overall prevalence, 69 percent; P=0.002 for the com-
parison among centers). A somatic presentation was
more common at centers where patients lacked an
ongoing relationship with a primary care physician
than at centers where most patients had a personal
physician (odds ratio, 1.8; 95 percent confidence in-
terval, 1.2 to 2.7). Half the depressed patients report-
ed multiple unexplained somatic symptoms, and 11
percent denied psychological symptoms of depres-
sion on direct questioning. Neither of these propor-
tions varied significantly among the centers. Although
the overall prevalence of depressive symptoms var-
ied markedly among the centers, the frequencies of
psychological and physical symptoms were similar.
Conclusions
Somatic symptoms of depression are
common in many countries, but their frequency var-
ies depending on how somatization is defined. There
is substantial variation in how frequently patients
with depression present with strictly somatic symp-
toms. In part, this variation may reflect characteris-
tics of physicians and health care systems, as well as
cultural differences among patients. (N Engl J Med
1999;341:1329-35.)
©1999, Massachusetts Medical Society.
From the Center for Health Studies, Group Health Cooperative, Seattle
(G.E.S., M.V.); Azienda Ospedaliera Ospedale de Circolo e Fondazione
Macchi, Varese, and Dipartimento di Medicina e Sanita Pubblica, Servizio
di Psicologia Medica, Istituto di Psichiatria, Universita de Verona, Verona
— both in Italy (M.P.); Departamento de Psiquiatria y Salud Mental, Uni-
versidad de Chile, Santiago, Chile (C.F.); the Departments of Psychiatry
and Health Sciences, University of Groningen, Groningen, the Netherlands
(J.O.); and the Institute of Psychiatry, King’s College, London (J.O.). Ad-
dress reprint requests to Dr. Simon at the Center for Health Studies, Group
Health Cooperative, 1730 Minor Ave., Suite 1600, Seattle, WA 98101-
1448, or at simon.g@ghc.org.
The investigators who participated in the study are listed in the Appendix.
OMATIZATION is a frequently cited feature
of depression in patients seen by primary care
physicians.
1-3
Some studies suggest that pa-
tients in non-Western cultures or developing
countries report somatic symptoms and deny psy-
chological symptoms more frequently than patients
in Western or developed countries.
4-7
One conclu-
sion drawn from these data is that patients from non-
Western cultures and those of lower socioeconomic
status are less willing or less able to express emotion-
al distress.
8-11
Epidemiologic data, however, have not
shown cross-national differences in the somatization
of depression. Community surveys with the use of
standardized interviews have shown a similar balance
between psychological and somatic symptoms in non-
Western and Western countries.
12
According to data
from clinical studies in which structured interviews
were used, the reporting of somatic symptoms by de-
pressed patients is widespread.
7,13,14
As Kirmayer and Robbins
15,16
and Kellner
17
have
noted, the term “somatization” refers to a variety of
phenomena. We identified three different definitions
of somatization used in earlier investigations. The
first emphasizes presentation with somatic symptoms.
Goldberg and Bridges
18,19
point out that many pa-
tients with psychiatric disorders seek care for somat-
ic symptoms. According to this definition, patients
with somatization are those who have psychiatric dis-
orders but who present with somatic symptoms. The
S
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1330
·
October 28, 1999
The New England Journal of Medicine
second definition emphasizes the association between
depression and medically unexplained somatic symp-
toms.
20-23
Barsky
24
describes the influence of psycho-
logical distress on the perception or reporting of so-
matic symptoms as “somatosensory amplification.”
According to this view, patients with somatization
are those who have psychological disorders but who
report multiple unexplained somatic symptoms. The
third definition emphasizes the denial of psycholog-
ical distress and the substitution of somatic symptoms.
From this perspective, somatization is a psychologi-
cal defense against the awareness or expression of psy-
chological distress. Nemiah
25
and Lesser
26
view so-
matization as related to alexithymia (the inability to
express feelings). Kleinman
27,28
has described somat-
ic symptoms as an alternative “idiom of distress” that
is prevalent in cultures where psychiatric disorders
carry great stigma.
We used data from the World Health Organization
(WHO) collaborative study of psychological problems
in general health care to examine the somatization
of depression in primary care settings in countries rep-
resenting a range of cultures, levels of economic de-
velopment, and types of health care delivery. We used
standardized measures in 14 countries on 5 conti-
nents. This allowed an assessment of cross-national
differences that was more comprehensive than previ-
ous assessments.
METHODS
Study Design
The WHO collaborative study examined the epidemiology of
common psychological disorders among patients visiting primary
care clinics in Ankara, Turkey; Athens, Greece; Bangalore, India;
Berlin, Germany; Groningen, the Netherlands; Ibadan, Nigeria;
Mainz, Germany; Manchester, United Kingdom; Nagasaki, Japan;
Paris, France; Rio de Janeiro, Brazil; Santiago, Chile; Seattle; Shang-
hai, China; and Verona, Italy. Centers were recruited on the basis
of geographic diversity, previous success in collaborative research,
and access to primary care facilities considered to be representa-
tive of local facilities. The study protocol was approved by local
ethics or institutional review boards at all centers. Written informed
consent was obtained from all patients. The study methods are
described in detail elsewhere
29,30
and are summarized here.
During the period from May 1991 to April 1992, each center
screened a consecutive or random sample of patients between the
ages of 18 and 64 years who were seeking care at primary care
facilities. Before the visit, patients were asked to complete the 12-
item General Health Questionnaire,
31
a self-reported measure of
general psychological distress. A total of 25,916 patients complet-
ed the questionnaire. The overall response rate was 96 percent
(range, 91 to 100). Patients were selected for the second-stage
diagnostic assessment on the basis of score thresholds that var-
ied according to the center (100 percent of patients with scores
on the General Health Questionnaire that exceeded the 80th
percentile for the particular center were selected, as well as 35
percent of patients scoring between the 60th and 80th percen-
tiles and 10 percent of patients scoring below the 60th percen-
tile).
32
Among the 8785 patients who met the criteria to be
selected for the second-stage interview, the response rate was 62
percent (range, 43 to 99). Respondents and nonrespondents did
not differ significantly with respect to age, sex, or score on the
General Health Questionnaire.
In the second-stage evaluation (involving 5447 patients), we
used a primary care version of the Composite International Di-
agnostic Interview,
33
a fully structured diagnostic interview devel-
oped by WHO for use in cross-national psychiatric studies. De-
pression was assessed according to the nine criteria listed in the
Diagnostic and Statistical Manual of Mental Disorders,
fourth edi-
tion (DSM-IV),
1
for the diagnosis of a major depressive episode:
depressed mood, loss of interest in activities, change in weight or
appetite, insomnia or hypersomnia, psychomotor agitation or re-
tardation, fatigue, feelings of worthlessness or inappropriate guilt,
impaired concentration or memory, and suicidal ideation. Soma-
tization was assessed according to the symptoms listed in DSM-IV
1
or the
International Classification of Diseases, 10th Revision
(ICD-
10),
2
as diagnostic criteria for somatoform disorders. The inter-
viewer first determined whether each symptom had ever occurred
(e.g., “Have you ever had a lot of trouble with back pain?”). For
each positive response, the interviewer asked a structured sequence
of questions to determine whether the symptom was clinically im-
portant and to obtain specific information about its cause (e.g.,
questions about whether diagnostic testing had been done and
whether a diagnosis had been made). A physician reviewer at each
center classified each symptom as medically explained or unex-
plained. Standard diagnostic-interview questions about lifetime
history were supplemented with questions about current symp-
toms. Additional questions concerned presenting symptoms or rea-
sons for seeking care (up to three were recorded).
The severity of medical illness was assessed with the use of
both a checklist of 20 chronic medical conditions, which the pa-
*Type A centers were characterized by ongoing patient–physician rela-
tionships, scheduled appointments, detailed medical records, and an em-
phasis on the privacy of the visit. Type B centers were characterized by un-
scheduled appointments and patient–physician relationships that were not
ongoing. The level of economic development was based on the United
Nations Human Development Index for 1992.
35
†One of two clinics in Athens was classified as type A, and the other as
type B.
T
ABLE
1.
C
LASSIFICATIONS
OF
THE
S
TUDY
C
ENTERS
.*
Type A center Type B center
Athens, Greece†
Berlin, Germany
Groningen, the Netherlands
Mainz, Germany
Manchester, United Kingdom
Paris, France
Santiago, Chile
Seattle
Verona, Italy
Ankara, Turkey
Athens, Greece†
Bangalore, India
Ibadan, Nigeria
Nagasaki, Japan
Rio de Janeiro, Brazil
Shanghai, China
Higher level of development Lower level of development
Berlin, Germany
Groningen, the Netherlands
Mainz, Germany
Manchester, United Kingdom
Nagasaki, Japan
Paris, France
Seattle
Verona, Italy
Ankara, Turkey
Athens, Greece
Bangalore, India
Ibadan, Nigeria
Rio de Janeiro, Brazil
Santiago, Chile
Shanghai, China
Western Europe and
North America
Africa, Asia,
and South America
Athens, Greece
Berlin, Germany
Groningen, the Netherlands
Mainz, Germany
Manchester, United Kingdom
Paris, France
Seattle
Verona, Italy
Ankara, Turkey
Bangalore, India
Ibadan, Nigeria
Nagasaki, Japan
Rio de Janeiro, Brazil
Santiago, Chile
Shanghai, China
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AN INTERNATIONAL STUDY OF THE RELATION BETWEEN SOMATIC SYMPTOMS AND DEPRESSION
Volume 341 Number 18
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tient completed, and a rating of severity on a five-point scale by
the treating physician. Each participating center completed trans-
lation and back-translation of the diagnostic interview, followed
by extensive field testing and reliability testing.
29
Analysis of the Data
Primary analyses, which were limited to patients with a current
diagnosis of depressive disorder, examined variations in the prob-
ability of somatized depression (according to each of the three
definitions described above) among the centers. All comparisons
were adjusted for age, sex, educational level, and coexisting med-
ical illness (according to both the physician’s rating of the severity
of medical illness and the presence or absence of at least one
chronic medical condition checked off by the patient).
Secondary analyses examined specific classifications of the
study centers. The first (described by Üstün and VonKorff
34
) in-
volved the type of primary care facility. In this classification, type
A centers were characterized by an ongoing relationship between
each patient and a personal physician, scheduled appointments,
detailed medical records, and careful attention to the privacy of
the medical encounter. Type B centers were characterized by a
walk-in style of care, without scheduled appointments or ongo-
ing patient–physician relationships. Consultations between patient
and physician were typically less private at type B centers than at
type A centers. Additional classifications grouped centers accord-
ing to geographic region (Western Europe and North America vs.
Africa, Asia, and South America) and level of economic develop-
ment (with the use of the United Nations Human Development
Index for 1992
35
). Table 1 shows the three classifications. Addi-
tional analyses examined patterns of reported symptoms among
the patients who were interviewed (those with and those without
a current diagnosis of depressive disorder).
Statistical Analysis
All analyses are based on symptoms and diagnoses in the
month preceding the interview. Although we report the actual
(unweighted) sample size for all analyses, all results incorporate
weights to correct for the undersampling of patients with lower
scores on the General Health Questionnaire and for nonrespond-
ents at the second-stage assessment.
32
All analyses (linear regres-
sion for comparisons of continuous measures and logistic regres-
sion for comparisons of categorical measures) were conducted
with the use of SPSS for Windows and WesVar Complex Sam-
ples software (both from SPSS, Chicago). Because standard sta-
tistical software may underestimate variance (and overestimate
statistical significance) in studies of stratified samples, the Wes-
Var program was used to calculate variances by means of the
jackknife method.
36,37
RESULTS
A total of 1146 patients met the DSM-IV criteria
for major depression (weighted prevalence, 10.1 per-
cent) (Table 2). As reported previously,
29
the preva-
lence of depression varied widely among the centers.
First Definition of Somatization
We examined the first definition of somatization
(somatic presentation) by comparing the proportion
of patients at each center who met the criteria for a
depressive disorder and who reported only somatic
symptoms as the reason for visiting the physician. As
shown in Table 2, this proportion ranged from 45
percent in Paris to 95 percent in Ankara, Turkey (over-
all prevalence, 69 percent). In a logistic-regression
model adjusted for age, sex, educational level, and
coexisting medical conditions, the probability of a
somatic presentation varied significantly among the
centers (P=0.002). According to this definition, the
*The definitions of somatization are explained in the Methods section.
T
ABLE
2.
P
REVALENCE
OF
S
OMATIZATION
, A
CCORDING
TO
V
ARIOUS
D
EFINITIONS
,
AMONG
P
ATIENTS
WITH
M
AJOR
D
EPRESSION
.
L
OCATION
OF
C
ENTER
M
AJOR
D
EPRESSION
D
EFINITION
OF
S
OMATIZATION
*
WEIGHTED
PREVALENCE
UNWEIGHTED
NO
.
OF
CASES
SOMATIC
PRESENTATION
UNEXPLAINED
SOMATIC
SYMPTOMS
DENIAL
OF
PSYCHOLOGICAL
SYMPTOMS ANY ALL
% % of patients with depression
Ankara, Turkey 10.8 94 95 51 5 94 2
Athens, Greece 7.1 38 91 36 26 88 10
Bangalore, India 8.5 70 87 62 4 94 1
Berlin, Germany 5.3 54 74 40 26 88 11
Groningen, the Netherlands 14.4 108 67 61 14 86 6
Ibadan, Nigeria 4.1 25 88 42 17 90 4
Mainz, Germany 10.0 55 85 30 15 93 4
Manchester, United Kingdom 17.1 159 60 40 14 73 2
Nagasaki, Japan 1.5 16 77 50 20 77 13
Paris, France 13.6 128 45 47 12 77 2
Rio de Janeiro, Brazil 18.3 151 69 60 2 89 0
Santiago, Chile 27.3 117 68 59 5 88 3
Seattle 6.4 60 75 42 8 87 3
Shanghai, China 2.4 39 87 33 16 88 2
Verona, Italy 4.6 32 53 36 16 78 0
Total 10.1 1146 69 50 11 85 4
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1332
·
October 28, 1999
The New England Journal of Medicine
centers with the highest rates of somatized depression
were Ankara, Turkey; Athens, Greece; Ibadan, Nigeria;
Bangalore, India; and Shanghai, China. Secondary
analyses examined the probability of somatic presen-
tation according to the three classifications of study
centers. A somatic presentation was more common in
type B centers than in type A centers (odds ratio,
1.8; 95 percent confidence interval, 1.2 to 2.7). This
form of somatization did not vary significantly ac-
cording to the geographic or economic classification
of the centers.
Second Definition of Somatization
We next examined differences among centers ac-
cording to the second definition of somatization,
the reporting of medically unexplained somatic symp-
toms. The somatization section of the diagnostic
interview included 41 such symptoms. To examine
the prevalence of somatized depression according to
this definition, we computed the proportion of pa-
tients with depressive disorder who met the criteria of
Kroenke et al.
38
for “multisomatoform disorder” (i.e.,
at least three unexplained somatic symptoms). This
proportion was 50 percent for all the centers com-
bined and exceeded 40 percent at 9 of the 15 centers
(Table 2). After adjustment for age, sex, educational
level, and coexisting medical conditions, the proba-
bility of unexplained somatic symptoms did not vary
significantly among the centers (P=0.09).
According to the second definition, the centers
where depression was most often somatized were
Bangalore, India; Groningen, the Netherlands; Rio
de Janeiro, Brazil; and Santiago, Chile — the cen-
ters with the highest overall rates of reported so-
matic symptoms. This finding suggests that varia-
tion in unexplained somatic symptoms may simply
reflect overall differences in symptom reporting (rath-
er than differences in the strength of the relation
between depression and unexplained somatic symp-
toms). To address this issue, we compared the num-
ber of unexplained somatic symptoms in patients
who had a major depressive disorder with the num-
ber in those who did not. The mean (±SD) number
of unexplained somatic symptoms reported was 4.4±
4.2 among the patients with major depression, as
compared with 1.2±1.9 among those without ma-
jor depression. In a logistic-regression model adjust-
ed for age, sex, and educational level, patients with
depression were significantly more likely to report
unexplained somatic symptoms than those without
depression (odds ratio, 3.5; 95 percent confidence in-
terval, 3.3 to 3.8). The strong relation between de-
pression and unexplained somatic symptoms was a
consistent finding among the centers, with center-spe-
cific odds ratios ranging from 2.4 to 4.8 (P<0.001
at all centers). This association did not vary signifi-
cantly with any of the three classifications of study
centers.
Third Definition of Somatization
We then examined variation in somatization ac-
cording to the third definition: denial of psycholog-
ical symptoms of depression on direct questioning.
The diagnostic interview included direct questions
about each symptom included in nine DSM-IV cri-
teria for the diagnosis of depression. For each center,
we calculated the proportion of patients with major
depression who denied the two most overtly psycho-
logical symptoms (depressed mood and feelings of
guilt or worthlessness) during the diagnostic inter-
view. As shown in Table 2, the overall prevalence was
11 percent, and it did not exceed 26 percent at any
center. After adjustment for age, sex, educational lev-
el, and coexisting medical conditions, the probability
of somatized depression according to the third def-
inition did not vary significantly among the centers
(P=0.07). The centers where depression was most
often somatized were Athens, Greece; Berlin, Ger-
many; Nagasaki, Japan; and Ibadan, Nigeria.
Secondary analyses examined the tendency to deny
psychological symptoms among all patients inter-
viewed. Because the prevalence of depressive symp-
toms varied widely among the centers, we examined
the tendency to deny psychological symptoms of de-
pression in relation to the reporting of somatic de-
pressive symptoms (i.e., the relative balance of psy-
chological and somatic symptoms of depression). For
these analyses, the nine DSM-IV diagnostic criteria
for depression were classified as psychological (de-
pressed mood, loss of interest in activities, impaired
concentration, feelings of worthlessness or guilt, and
suicidal ideation) or physical (insomnia or hypersom-
nia, change in weight or appetite, fatigue, and psy-
chomotor agitation or retardation). Figure 1 shows
the mean number of psychological symptoms of de-
pression as compared with the mean number of
physical symptoms for each center. Although the over-
all prevalence of depressive symptoms varied greatly
among the centers, the balance of psychological and
physical symptoms was similar. The tendency to ad-
mit or deny psychological symptoms of depression
did not vary significantly according to any of the three
classifications of study centers.
Agreement among Definitions
Finally, we examined the extent of agreement
among the three definitions of somatized depression
(depression with a strictly somatic presentation, de-
pression accompanied by at least three unexplained
somatic symptoms, and depression with the denial
of psychological symptoms). As shown in Table 2,
85 percent of patients with major depression met at
least one of the definitions, but only 4 percent met
all three. In none of the three possible comparisons
was the agreement between a pair of definitions (as
measured by the kappa statistic) greater than that
which would be expected by chance. The proportion
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AN INTERNATIONAL STUDY OF THE RELATION BETWEEN SOMATIC SYMPTOMS AND DEPRESSION
Volume 341 Number 18
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1333
of patients with major depression who presented with
somatic symptoms but acknowledged psychological
symptoms when asked about them (i.e., patients who
satisfied the first definition of somatized depression
but not the third definition) was 60 percent overall
and exceeded 40 percent at every center.
DISCUSSION
The sample of patients at each center was not rep-
resentative of the regional or national population.
Each center attempted to select representative pri-
mary care facilities, and the patients enrolled in the
study were representative of those seeking care at
the facilities. All facilities, however, were located in
urban areas, and all patients were seeking care from
physicians trained in Western medicine.
Although each definition of somatization that we
studied accounted for somatized depression in a sub-
stantial number of patients, the agreement among
definitions was no greater than one would expect by
chance. A similar finding was reported by Kirmayer
and Robbins.
16
Given the strong association between
psychological distress and somatic symptoms in our
study
39
and in other epidemiologic studies,
22,23
poor
agreement between the second definition (the re-
porting of medically unexplained somatic symptoms)
and the third (the denial of psychological symp-
toms) might have been expected. A low level of
agreement between different definitions of somatiza-
tion may explain why previous studies (using various
definitions and various methods) have reached in-
consistent conclusions about cross-national or cross-
cultural differences in somatization.
According to our third definition (the denial of
psychological symptoms), somatized depression was
relatively uncommon at all centers. The data in Fig-
ure 1 suggest that patients at different primary care
centers differed markedly with respect to the overall
likelihood of reporting symptoms of depression but
differed little with respect to the reporting of phys-
ical symptoms exclusively. The variation among the
centers in the proportion of patients with depression
who denied psychological symptoms was no greater
than the variation that would be expected by chance.
According to our second definition (multiple un-
explained somatic symptoms), the somatization of de-
pression was common; the overall prevalence among
patients with major depression was 50 percent. The
probability of somatized depression according to this
definition was similar among the centers. Further-
more, variation among the centers seemed to reflect
differences in general rates of symptom reporting
rather than any variation in the association between
depression and unexplained somatic symptoms. Broad-
er analyses of symptom patterns among all patients
interviewed showed strong (and generally similar) as-
sociations between depression and unexplained so-
matic symptoms at every center.
Although somatization as defined on the basis of
presenting symptoms had the highest overall preva-
lence (69 percent), it was the only definition of so-
matization for which there were significant variations
among the centers. The probability of a somatic pres-
entation was significantly greater in the walk-in cen-
ters than in those where patients had personal phy-
sicians. We cannot, of course, determine whether this
observation reflects characteristics of the patients (e.g.,
“psychological mindedness” or expectations about the
scope of primary care), characteristics of the physi-
cians (e.g., training and views about psychological
disorders), or the nature of the health care delivery
(e.g., the duration of the visit, degree of privacy, and
extent of the physician’s familiarity with the patient’s
medical history and life situation).
We should note that the concept of somatization
itself rests on the culturally determined assumption
that psychological symptoms of depression are more
central or primary than somatic symptoms. Our find-
ings suggest that somatic symptoms are a core com-
ponent of the depressive syndrome. Instead of exam-
ining the phenomenon of somatization, we could have
studied “psychologization” among depressed patients
presenting with primarily psychological symptoms.
We should emphasize the discrepancy between our
first and third definitions of somatization: 60 percent
of patients with major depression presented with
somatic symptoms but acknowledged psychological
Figure 1.
Mean Numbers of Psychological and Physical Symp-
toms of Depression at the 15 Study Centers.
Each point represents the mean number of physical symptoms
and the mean number of psychological symptoms for primary
care patients at a single center. The total sample consisted of
5447 patients. Psychological symptoms were defined as de-
pressed mood, loss of interest in activities, impaired concentra-
tion, feelings of worthlessness or guilt, and suicidal ideation.
Physical symptoms were defined as insomnia or hypersomnia,
change in weight or appetite, fatigue, and psychomotor agita-
tion or retardation.
0.0
2.0
0.0 1.5
0.5
1.0
1.5
0.5 1.0
No. of Physical Symptoms
Nagasaki
Shanghai
Bangalore
Santiago
Rio de Janeiro
Manchester
Mainz
Berlin
Ankara
Groningen
Paris
Seattle
Ibadan
Verona
Athens
No. of Psychological Symptoms
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1334
·
October 28, 1999
The New England Journal of Medicine
symptoms (such as depressed mood or guilt) when
specifically asked about them. A similar pattern has
been observed in other studies of depression in pri-
mary care practice.
18,19,40
The reporting of somatic
symptoms may not reflect an unwillingness or inabil-
ity to acknowledge psychological distress. Instead, pa-
tients may believe that the reporting of somatic symp-
toms is a more appropriate route for seeking help from
a primary care physician. Goldberg and Bridges
18,19
have called this process “facultative somatization” and
have characterized the initial reporting of somatic
symptoms as a “ticket of admission” to the primary
care clinic. Thus, without specific questioning, depres-
sion and other psychological disorders may not be
recognized.
In this report, we have not considered cross-nation-
al or cross-cultural differences in the specific somatic
symptoms associated with psychological disorders.
41,42
As we reported elsewhere, however, we found no re-
lation between economic development and the types
of somatic symptoms associated with psychological
distress.
39
We also could not examine differences
among centers in the meaning patients attached to
symptoms of depression.
Our data provide mixed support for claims about
cross-national or cross-cultural differences in soma-
tization. When somatization was defined in terms of
patients’ reports about symptoms (either denial of
psychological symptoms or reporting of medically
unexplained somatic symptoms), we found no sig-
nificant variation in somatization among the study
centers — and no evidence of greater somatization
in the non-Western or less developed countries. These
findings are in agreement with earlier reports that
the symptomatic manifestations of depression are sim-
ilar throughout the world.
13,14,43
When somatization
was defined according to presenting symptoms, we
found greater variation among the centers, with a
greater tendency toward somatic presentations at cen-
ters offering walk-in care than at those offering a more
personal form of primary care. In other words, the
symptomatic experience of depression seems to vary
little from one country to another, whereas the in-
teractions between doctors and depressed patients
may vary considerably. The somatic presentation of
depression or other psychological illness should there-
fore not be attributed solely to somatization by pa-
tients. The definition of legitimate reasons for seek-
ing care reflects the interaction between patients and
physicians as well as the structure of the primary care
system.
Supported by grants from the World Health Organization, the National
Institute of Mental Health (MH47765), Delagrange Laboratories, and
Synthelabo Pharmacie.
APPENDIX
In addition to the authors, investigators participating in the study of psy-
chological problems in general health care included O. Ozturk and M. Re-
zaki, Ankara, Turkey; C. Stefanis and V. Mavreas, Athens, Greece; S.M.
Channabasavanna and T.G. Sriram, Bangalore, India; H. Helmchen and M.
Linden, Berlin, Germany; W. van den Brink and B. Tiemens, Groningen,
the Netherlands; M. Olawatura and O. Gureje, Ibadan, Nigeria; O. Benkert
and W. Maier, Mainz, Germany; R. Gater and S. Kisely, Manchester, Unit-
ed Kingdom; Y. Nakane and S. Michitsuji, Nagasaki, Japan; Y. Lecrubier
and P. Boyer, Paris; J.-A. Costa e Silva and L. Villano, Rio de Janeiro, Bra-
zil; R. Florenzano and J. Acuna, Santiago, Chile; H.-Q. Yan and S.F. Xaio,
Shanghai, China; and M. Tansella and C. Bellantuono, Verona, Italy. The
members of the study advisory group were J.-A. Costa e Silva, D.P. Gold-
berg, Y. Lecrubier, and H.-U. Wittchen. Members of the coordinating staff
at WHO headquarters included N. Sartorius and T.B. Üstün.
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