Am

J Psychiatry

expressed viewpoints

135:8,

in this of the

August

1978

paper do sponsoring

MICHAEL

not necessarily represent the agencies or of other investiga-

tons of the IPSS.

The

authors

The

wish

to

acknowledge

Prevalence

Diagnostic

the

cooperation

of

ofSchizophrenia:

ALAN

TAYLOR,

M.D.,

AND

RICHARD

ABRAMS,

KRAEPELIN’S

DISEASE

broadened

ABRAMS

Using

Modern

CONCEPT

but essentially

to produce psychiatric applied these criteria

We were

(3). of 247

1976.

diagnoses given

Address

reprint

requests

Criteriafor

to

Dr. Taylor.

0002-953X/78/0008-0945$0.45

©

considering

that

patient

was

interviewed

by one

of us and

a

to insure all

the

accuracy

data

and completeness

collection

were

made

chief

complaint,

by

was one

completed, of

history

us

(R.A.),

of present

of data. research who

was

illness,

and mental status portions of the research records and was blind to all identifying information and all demographic, family history, and treatment response data. Research diagnoses were made according to the following criteria.

Dr. Taylor is Professor and Chairman, and Dr. Abrams is Professor and Vice-Chairman, Department of Psychiatry and Behavioral Sciences, University of Health Sciences/The Chicago Medical School, 60064.

Each

reviewed

secutive admissions to an acute treatment psychiatric unit of an inner-city municipal general hospital and identified only 1 1 patients (4.5%) who could be called schizophrenic (4). We also applied (5) the St. Louis research criteria (6) to all patients (N= 121) in the

Ill.

low yield,

psychiatric resident who was specifically trained in phenomenology and data collection and who followed a semi-structured outline for collecting the necessary clinical and demographic data. At the time of discharge, a summary was prepared for each patient, which included all information and was meticulously After

Chicago,

by this

This study was done on an acute treatment university psychiatric inpatient unit serving a suburban-rural population in New York State. We included all consecutive admissions for the 22 months ending May

con-

North

puzzled

as and and for

METHOD

(I) of dementia pnaeunchanged by Bleuler,

symptoms to a sample

M.D.

the usual national range of admission prevalence of schizophrenia is 24%-40% (7), and when the oppontunity arose again, this time in a different population, we decided to repeat the study using slightly broadened criteria and a more rigorous methodology.

has dominated psychiatric nosology since 1893. In a series of clinical investigations of manic-depressive illness and schizophrenia, we attempted to establish diagnostic validity for Knaepelin’s disease concept by applying Sydenham’s general principles for defining a disease entity according to the research method outlined by Robins and Guze (2). Our diagnostic criteria for schizophrenia included formal thought disorder, emotional blunting, hallucinations or delusions, and the absence of diagnosable affective disorder, coarse brain disease, or history of any medical condition

50,

RICHARD

sample who were diagnosed on clinical grounds schizophrenic or manic by an admitting physician identified only 11 patients (12% of the subgroup 4.5% of the entire sample) who met the criteria schizophrenia.

,

Building

AND

Southeast Community Hospital, Washington, D.C., Georges General Hospital, Cheverly, Md. , and Grove Hospital Center, Catonsville, Md. Ms. Sherry assisted in interviewing and data analysis.

A Reassessment

Using strict research diagnosis criteria, the authors f ound a hospital admission prevalence of schizophrenia of about 6%. Other recent studies yielded similar fi gures with correspondingly low figures for the morbid risk ofschizophrenia in the general population and in the relatives ofschizophrenic probands. In view of the data supporting the validity of this “narrow” concept ofschizophrenia, the authors suggest that the true prevalence ofschizophrenia is much lower than generally accepted.

known We

TAYLOR

Criteria

BY MICHAEL

cox,

Greater Prince Spring Henig

ALAN

1978

The through American

Research

criteria 4: Psychiatric

for

Diagnoses

schizophrenia

Association

included

all

of

I

945

-

THE

PREVALENCE

OF

Am

SCHIZOPHRENIA

I At least one of a through c: a) formal thought disorder (driveling, tangentiality, neologisms, panaphasias, non sequituns, private words, stock words), b) first rank symptoms (at least one), and c) emotional blunting (a constricted, inappropriate, unrelated affect of decreased intensity with indifference/unconcern for loved ones, lack of emotional nesponsivity, and a loss of social graces). .

,

2. 3.

Clean consciousness. No diagnosable

affective

4. No diagnosable lucinogenic

on

disorder.

coarse

brain

psychostimulant

disease, drug

medical condition known to symptoms. A diagnosis of mania required

no past abuse,

cause

hal-

and

no

schizophrenic

1. Hyperactivity. 2. Rapid/pressured speech. 3. Euphonic/expansive/irritable

cal

illness

The

known

criteria

3 of the

mood,

coarse in the

to cause

with

brain disease, no psychopast month, and no medimanic

for endogenous

dysphonic,

symptoms.

depression

included

all

on anxious

mood.

2. Three of a thnough f: a) early morning waking, diurnal mood swing (worse in a.m.), c) weight loss

b) of

more

on

than

agitation,

five pounds

in three

e) suicidal

weeks,

d) retardation

thoughts/behavior,

and

f) feelings

of guilt/hopelessness/worthlessness. 3. No diagnosable steroids on nesenpine

illness known Additional tenia

previously

coarse in past

to cause diagnoses reported

This study is consistent yield of patients satisfying

phnenia. 712

Ifthe

brain disease, month, and

no no

depressive symptoms. were made according

use of medical

to cni-

(3).

LTS

There were 620 consecutive admissions during the study period, representing 465 individual patients. Of these patients, 31 (6.7%) received a research diagnosis ofschizophnenia, and 160 (34.4%) a research diagnosis of affective disorder (25.8% were manic, 8.6% depressed). Of the remaining 274 patients, 211 (45.4%) were diagnosed as having coarse brain disease, alcoholism, stress termed

drug abuse, reaction, on undiagnosed.

personality no illness, We further

disorder, neurosis, and 63 (13.6%) were examined the undiag-

nosed group to see whether it contained any patients who might have approximated our criteria for schizophnenia. We reviewed the hospital discharge diagnoses for this purpose and found 2 patients diagnosed as schizophrenic. One of them failed to satisfy any of our criteria,

and

1 satisfied

phnenia. If the latter sample, the percentage crease to 6.9%. 946

some

1978

with our rigorous

from

yield

the two

only

43

prior one in its low criteria for schizo-

studies

are combined,

schizophnenics,

on 6.0%

of the entire sample. This figure is unexpectedly low, and for comparison we reviewed some of the more necent literature on the diagnosis of schizophrenia. Inpatient

and

Outpatient

Studies

In a random selection Hospital in St. Louis, the St. Louis criteria they

found

of new admissions to Renard Helzen and associates (8) used (6) to diagnose schizophrenia,

in only

5%

of the

202

patients

they

of our

criteria

individual were of schizophnenics

for

added

schizo-

to would

our in-

Hospital

in the

l930s

and

1940s

and

identified

only 200 patients (5.3%) who satisfied the research cniteria for schizophrenia. Woodruff and associates (10) studied 500 outpatients randomly selected for participation in a clinical, family, and follow-up study; using the St. Louis criteria they identified only 22 patients (4.4%) with a diagnosis of schizophrenia. Nielsen and Nielsen (11) analyzed the psychiatric diagnoses for 976 patients referred to a Danish community psychiatric clinic during 1957-1974. Diagnoses were made according to WHO criteria but with the characteristically nan-

now Danish concept of manic-depressive ceived a diagnosis Strauss and Gift (12) for schizophrenia to pitalized for functional St. Louis criteria, (3.3%) agnostic

RESU

data

individuals

pathic

a broad

following:

1. Sad,

August

interviewed. In their Iowa 500 study, Tsuang and Winokun (9) applied the St. Louis criteria to a sample of 3,800 charts of patients admitted to Iowa Psycho-

criteria:

affect. 4. No diagnosable stimulant drug abuse

135:8,

DISCUSSION

which

all 4 of the following

J Psychiatry

of schizophrenia and a illness. Only 6 patients of schizophrenia. Most applied various diagnostic a sample of 272 patients psychiatric disorder. they diagnosed only

as schizophrenic; Cnitenia (13),

broad one (0.6%) nerecently, criteria first

hos-

Using the 9 patients

according to the Research only 4 (1.5%) were so

Didiag-

nosed. Weissman and associates (14) found only 2 of 511 patients (0.4%) who satisfied the Research Diagnostic Criteria for schizophrenia. It is clean from the above data that the application of rigorous diagnostic criteria for schizophrenia to a wide variety mission

of patient prevalence

in all the figures).

samples figures,

studies

Population

yields consistently ranging from 0.6%

quoted

(mean=3.5%

for

low adto 6.7%

9 different

Studies

Recent estimates of the morbidity risk for phrenia in the general population have been erably lower than the 1.0% classically described Nielsen

and

Nielsen

(16)

reported

census

data

schizoconsid(15). on 80%

of the population the diagnostic

of the Danish criteria described

island of Samso, above. Of the

individuals

the

1 1 were

in

schizophrenic, risk of0.4%. ‘Tsuang

population,

yielding In the Iowa

M, Winokur

G, personal

diagnosed

an age-corrected 500 study’ a control communication.

using 4,941 as

morbidity group

of

Am

J Psychiatry

135:8,

August

MICHAEL

1978

414 first-degree relatives ofsurgical and tients was evaluated using a structured modified St. Louis research criteria for only 2 individuals received a diagnosis nia, yielding an age-corrected morbidity Family

orthopedic painterview and schizophrenia; of schizophnerisk of 0.6%.

Studies

The morbidity risk for schizophrenia gnee family members of schizophrenic

among first-deprobands re-

recent diagnostic trends. Older studies reported morbidity risks of9%-15% in the first-degree relatives of schizophrenic probands (14); more recent studies demonstrate much lower rates. Kety and associates (17) studied first-degree biological relatives of adopted schizophrenic probands using modified DSM-II cnitenia but requiring a consensus among 3 examiners and found a morbidity risk for schizophrenia ofonly 2.6%. Winokun and associates (18) conducted a blind family history assessment of first-degree relatives of 177 hebephrenic or paranoid schizophrenic probands and found a morbidity risk for schizophrenia of 2.75%. (Among the first-degree relatives of paranoid probands flects

the morbidity ducted amined phnenic

risk

was only

0.83%.)

Karlsson

(19) con-

a family study of schizophrenia in which he exthe hospital records of relatives of schizoprobands in Iceland and selected only those

with a definite, on schizophrenia.

specific diagnosis In that portion

of dementia of his study

pnaecox where he

provided data for all first-degree relatives (parents, sibs, and children), 33 of 1,135 relatives had schizophrenia, on 2.9%, compared with a 0.64% hospital admission rate for the general population born during the same period. The above figures for the hospital admission prevalence, population prevalence, and morbidity risk for first-degree relatives for schizophrenia are strikingly consistent in showing a five-fold reduction in

the diagnosis search used.

criteria

of schizophrenia on

‘

when

‘narrow”

either

European

specific criteria

neare

TAYLOR

AND

these

validated

criteria

tients labeled had diagnosable

low

yield

of patients

schizophrenia fying research search criteria

ported

we also

schizophrenic affective

showed

by disorder.

these

low figures

are a function

of rigorous

cni-

teria on methodology and not of any change in the prevalence of schizophrenia is shown in Strauss and Gifts’ study (12), where applying broaden criteria led to a hospital admission prevalence for schizophrenia of 20%-25%, rather than the l.5%-3.3% found using research criteria. Data from other studies (20-22) demonstrate that failure to use rigorous criteria allows cultunal sensitivity, theoretical bias, and availability of

new treatments to unduly influence the frequency the diagnosis of schizophrenia. Although we might consider recent prevalence ures

for

schizophrenia

remarkably

come

as no surprise

nosis mitted

of dementia praecox to his Munich clinic

tion

further

supports

low,

to Kraepelin,

who

in only in 1893

the notion

that

they

made

fig-

research

of

pa-

criteria of the

criteria

for

a comparably

low

proportion

of schizophrenia

‘

The

diagnosis

of schizophrenia

ten of style or ceive a diagnosis

have another be subjected

phnenia

may

lithium

ion,

condition erroneously

(e.g., and

of illness.

merely

a mat-

Patients who newhen in fact they

affective disorder) may unnecessarily to chronic

neunoleptic drugs, with their high neurologic damage in the form of Patients with bipolar affective disan incorrect diagnosis of schizo-

be deprived the

is not

personal preference. of schizophrenia

administration of risk of permanent tardive dyskinesia. order who receive

ofappropniate

only

available

The

correct

treatment

preventive

diagnosis

agent

with for

this

of schizophrenia nature of the condi-

critical for research on the tion. It is generally acknowledged that many years of schizophrenia research have yielded virtually no hand data on the etiology of this condition. We believe this

ovendiagnosis

of schizo-

phnenia in the hospitals and clinics where was conducted. Reevaluating past data research criteria might clarify conflicting

due

the research using recent on ambiguous

is

data

in part

and open

to a five-fold

new

avenues

for future

research

efforts.

REFERENCES 1. Kraepelin

the diag-

the prevalence

many

and a high one of affective disorders, validating their criteria through a series of long-term follow-up and family studies (26-29). Employing similarly rigorous criteria, Winokun and coworkers (9, 18, 30) likewise demonstrated different symptom patterns, family illness patterns, and outcomes for schizophnenics compared with patients with affective disorders. Thus, the validity of the ‘narrow” diagnosis of schizophrenia has received confirmation through a variety of studies at different centers, suggesting that the low figures necently reported are an accurate reflection of the true prevalence of the condition.

2.

5% of patients ad(23). This observa-

that

nonneseanch A corollary

satisfying

of

would

ABRAMS

is an increased yield of patients satiscriteria for affective disorder. Using resimilar to ours, the St. Louis group re-

is also

That

RICHARD

schizophrenia has remained constant oven the years, with only diagnostic habits showing change. High diagnostic reliability among research groups using similar criteria is a prerequisite for studies on the validity of the diagnosis of schizophrenia. We have validated our research criteria for schizophrenia by demonstrating homogeneity of our patient samples for demographic, family history, neunopsychological, and treatment-response variables compared with samples of patients with affective disorder (3, 4, 24, 25). Using

form

CONCLUSIONS

ALAN

3.

E: Psychiatric.

Leipzig,

Meiner,

1893

Robins E, Guze SB: Establishment ofdiagnostic validity in psychiatric illness: its application to schizophrenia. Am J Psychiatry 126:983-987, 1970 Taylor MA, Gaztanaga P. Abrams R: Manic-depressive illness

and acute schizophrenia: a clinical, ment-response study. Am J Psychiatry

family history 131:678-682,

and treat1974

947

THE

PREVALENCE

OF

Am

SCHIZOPHRENIA

4. Taylor MA, Abrams R, Gaztanaga P: Manic-depressive and schizophrenia: a partial validation of research criteria utilizing neuropsychological testing. Compr 5.

illness diagnostic Psychiatry

US Department stitute of Mental

R: A critique

ofthe

St.

Louis

research

cri-

of Health, Health:

Education Mental

and Health

Welfare, Statistical

National Note

In138.

Washington, DC, US Government Printing Office, 1977 8. HelzerJE, Clayton Pi, Pambakian R, et al: Reliability of psychiatric diagnosis: II. The test-retest reliability ofdiagnostic classification. Arch Gen Psychiatry 34:136-141, 1977 9. Morrison i, Clancy J, Crowe R, et al: The Iowa 500: 1. Diagnostic validity in mania, depression, and schizophrenia. Arch Gen Psychiatry

27:457-461,

10. Woodruff

diagnosis.

II.

Nielsen service 12. Strauss ophrenia. 13. Spitzer nc

diagnosis

a

Dis

PS,

Guze

Nerv

Syst

SB:

Suicide

attempts

33:617-621,

U.S.

and

MM, urban

and

DSM-III.

Myers

JK,

community:

Am

J Psychiatry

Harding

PA:

1975-1976.

20.

Psychiatric Am

Kendell

763, 22.

23. 24.

25.

RE,

August

1978

J, Clancy J, et al: Iowa 500: the clinical of hebephrenic and paranoid schizophre-

Dis

159:12-19,

An Icelandic

1974

family

123:549-554,

1973

CooperiE,

Gourlay

study AJ,

of schizophrenia.

et al:

Br J

Diagnostic

criteria

of

1970

Kuriansky

26.

JB,

Gurland

Bi,

Spitzer

RL,

et al:

Trends

in the

quency of schizophrenia by different diagnostic criteria: Psychiatry 134:631-636, 1977 Meyer A: The approach to the investigation of dementia cox. Chicago Medical Record 39:441-445, 1917 Abrams R, Taylor MA, and paranoid schizophrenia: and treatment-response 642, 1974 Abrams

Arch Murphy

order.

R, Taylor

Gen

MA:

Psychiatry GE,

Arch

Woodruff

Gen

RA,

a prospective 1976

Herjanic

Psychiatry

M:

31:181-184,

Primary

J

prae-

Gaztanaga P: Manic-depressive a phenomenologic, family study. Arch Gen Psychiatry

Catatonia: 33:579-581,

fre-

Am

illness history

31:640-

clinical

study.

affective

dis-

1974

27.

Murphy GE, Woodruff RA, Herjanic M, et al: Validity of the diagnosis of primary affective disorder. A prospective study with a five-year follow-up. Arch Gen Psychiatry 30:751-756,

28.

Murphy clinical

disorders J

Ment

JL:

135:8,

American and British psychiatrists. Arch Gen Psychiatry 25:123-130, 1971 2 1 . Baldessarini R: Frequency of diagnosis of schizophrenia versus affective disorders from 1944 to 1968. Am I Psychiatry 127:759-

132:1187-1192,

Psychiatry

135:459-462, 1978 15. Slater E, Cowie V: The Genetics of Mental Disorders. London, Oxford University Press, 1971, p 13 16. Nielsen J, Nielsen IA: A census study of mental illness in Samso. Psychol Med 7:491-503, 1977 17. Kety 55, Rosenthal D, Wender PH, et al: The types and prevalence of mental illness in the biological and adoptive families of adopted schizophrenics, in The Transmission of Schizophrenia. Edited by Rosenthal D, Kety SS. Oxford, Pergamon Press, 1968, pp 345-362

948

J Nerv

Psychiatry

1972

J, Nielsen iA: Eighteen years ofcommunity psychiatric in the island ofSamso. BrJ Psychiatry 131:41-48, 1977 iS, Gift TE: Choosing an approach for diagnosing schizArch Gen Psychiatry 34:1248-1253, 1977 RL, Endicott J, Robins E: Clinical criteria for psychiat-

1975 14. Weissman in

1972

RA in, Clayton

psychiatric

nia.

19. Karlsson

16:91-96, 1975 Taylor MA, Abrams

teria for schizophrenia. Am J Psychiatry 132: 1276-1280, 1975 6. Feighner JP, Robins E, Guze SB, et al: Diagnostic criteria for use in psychiatric research. Arch Gen Psychiatry 26:57-63, 1972 7.

18. Winokur G, Morrison and genetic distinction

J Psychiatry

1974 GE, course

WoodruffRA, of primary

Herjanic affective

M, et al: Variability disorder. Arch Gen

of the Psychia-

try 30:757-761, 1974 29.

30.

Winokur Louis,

G. CV

Clayton Mosby

P1, Co.

Reich 1969

T:

Manic-depressive

Illness.

St

Winokur G: Relationship of genetic factors to course and drug response in schizophrenia, mania and depression, in Modern Problems of Pharmacopsychiatry, vol 10. Edited by Mendlewicz J. Basel, Karger, 1975, pp 1-11