Social Phobia Comorbidity and Morbidity in an Epidemiologic Sample Franklin R. Schneier, MD; Jim Johnson, PhDt; Christopher D. Michael R. Liebowitz, MD; Myrna M. Weissman, PhD \s=b\ Selected
sociodemographic and clinical features of social phobia were assessed in four US communities among more than 13 000 adults from the Epidemiologic Catchment Area study. Rates of social phobia were highest among women and persons who
were younger (age, 18 to 29 years), less educated, single, and of lower socioeconomic class. Mean
age at onset was 15.5 years, and first onsets after the age of 25 years were uncommon. Lifetime major comorbid disorders were present in 69% of subjects with social phobia and usually had onset after social phobia. When compared with persons with no psychiatric disorder, uncomplicated social phobia was associated with increased rates of suicidal ideation, financial dependency, and having sought medical treatment, but was not associated with higher rates of having made a suicide attempt or having sought treatment from a mental health professional. An increase in suicide attempts was found among subjects with social phobia overall, but this increase was mainly attributable to comorbid cases. Social phobia, in the absence of comorbidity, was associated with distress and impairment, yet was rarely treated by mental health professionals. The findings are compared and contrasted with prior reports from clinical samples.
(Arch Gen Psychiatry. 1992;49:282-288)
studies social in around the Prior Catchment Area of data found 6-month prevalences of DSM-III social phobia at two US sites of 0.9% to 1.7% for men and 1.5% to 2.6% for women,9 with overall 1-month, 6-month, and lifetime prevalences across four sites of 1.3%, 1.5%, and 2.8%, re¬
have examined the prevalence of world.1"8 Several phobia populations (ECA) study reports Epidemiologie 1
spectively.10 Social phobia in the US population has been further characterized by another ECA report11 that examined gender differences in the phobias. No significant gender differences in lifetime prevalence of social phobia or in age Accepted
publication June 12, 1991. From the Departments of Therapeutics (Drs Schneier and Liebowitz) and Clinical and Genetic Epidemiology (Drs Johnson and Weissman and Mr Hornig), New York State Psychiatric Institute, New York; and the Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY (Drs Schneier, Johnson, Liebowitz, and Weissman and Mr Hornig). tDr Johnson died January 10, 1992. Reprint requests to Anxiety Disorders Clinic, New York State Psychiatric Institute, 722 W 168th St, New York, NY 10032 (Dr Schneier).
for
Hornig;
found. The disorder was significantly less subjects over 65 years old than in subjects 18 to 24 years old. Among males it was less common in black men and in married men. Among females social phobia was significantly more common in divorced or separated at onset were common
women
in
and in
women
of low socioeconomic status.
Beyond these reports of prevalence and demographics, little has been reported about other characteristics of so¬ cial phobia in the general population. It is unclear to what extent these epidemiologically identified cases resemble the more extensively described social-phobic patients at¬ tending anxiety disorder clinics. Reported characteristics of the disorder based only on subjects with social phobia seeking treatment could represent selection for certain types of social phobia (eg, generalized type), greater im¬ pairment, higher or lower comorbidity, or greater access to mental health care. Few epidemiologie reports have examined impairment (social morbidity) or comorbidity in social phobia, and none have studied uncomplicated so¬ cial phobia or controlled for most comorbid disorders that may contribute to poor outcome. Several epidemiologie studies101225 that examined prevalence, age at onset, spe¬ cific anxiety symptoms, comorbidity, and treatmentseeking behavior have not reported findings for uncom¬ plicated social phobia or for social phobia separately from other phobic disorders, although clinical studies demon¬ strate differences in these features between social phobia, simple phobias, and agoraphobia.26"32 This article will examine several aspects of social pho¬ bia in the general population not reported in previous publications of ECA data, including measures of distress and morbidity (suicidal ideation, suicide attempts, finan¬ cial dependence), treatment utilization, and comorbidity with other psychiatric disorders. Findings will be com¬ pared with reports of clinical samples of social phobia. The
SUBJECTS AND METHODS
Epidemiologie Catchment Area The sample for this study is a subset of persons in the house¬ hold survey of the ECA program. The ECA study is an epidemi¬ ologie study of rates and risks for psychiatric disorders based on a probability sample of more than 18 000 adults aged 18 years and over, living in five US communities (New Haven, Conn; St Louis, Mo; Baltimore, Md; Durham, NC; and Los Angeles, Ca¬ lif). Response rates during the wave I interview ranged from 76% to 80%. A full description of the purpose, methods, and sampling frame can be found elsewhere.33"35
Downloaded From: http://archpsyc.jamanetwork.com/ by a New York University User on 05/31/2015
Each ECA site used the
Diagnostic
Interview Schedule dis¬
(DIS), which generated DSM-III diagnoses for the major
orders. A
core
set of
items,
including demographics
and
utilization, were also collected at all sites. The New Haven site, however, used version II of the DIS, which did treatment
not include social phobia items. Data from New Haven are not represented in this article, which is based on 13537 sub¬
jects
from the
remaining
four sites.
Comorbidity and Morbidity
Psychiatric Assessment The DIS is a highly structured interview, designed for use by lay interviewers in epidemiologie studies.36 The DIS includes a structured set of questions so that responses can be subjected to a computer algorithm to produce DSM-III psychiatric diagnoses. Classifications of pathologic features according to DSM-III crite¬ ria made via the interview questions of the DIS are referred to as DIS/DSM-ÍIÍ diagnoses. Subjects were told: Some people have phobias, that is, such a strong fear of some¬ thing or some situation that they try to avoid it, even though they
know there is no real danger. Have you ever had such an unrea¬ sonable fear of (—) that you tried to avoid it/them? Does having to avoid (—) interfere with your life or activities a lot? Subjects were asked these questions for a series of phobic sit¬ uations related to simple phobias and agoraphobia and for three social-phobic situations: (1) "eating in front of other peopleeither people you know or in public," (2) "speaking in front of a small group of people you know," and (3) "speaking to strang¬ ers or meeting new people." Subjects who had phobias of any of the above three situations were diagnosed as having DIS/ DSM-III social phobia. Age at onset was obtained for "any pho¬ bia," but in subjects with more than one phobic diagnosis, age at onset was not obtained for each phobic disorder separately (ie, social phobia, agoraphobia, or simple phobia). Age at onset was recorded in years, the range being 2 to 94 years. When subjects reported having social phobia their whole life, 2 years was recorded as age at onset. Discussions of the reliability and validity of the DIS in field surveys have appeared in several publications.37"42 A comparison was made of DIS diagnoses by lay interviewers and by psychi¬ atrists using a DSM-III checklist in 361 cases.37 The groups agreed on the presence of social phobia in 12 cases and the absence of social phobia in 319 cases, yielding an overall 92% agreement. In 15 cases each, one group diagnosed social phobia while the other did not, so prevalence estimates were the same in both groups. Rates of sensitivity and specificity were 44% and 96%, respec¬ tively ( .40, Yate's .61). Heizer et al37 suggested that a low score could be explained partly as a consequence of low base rates of the diagnosis, and low sensitivity could be partly a con¬ sequence of clustering of positive cases around the threshold for =
prior ECA analyses of subjects with simple phobia or dysthymia alone found no significant differences from subjects with no disorder (M.M.W., unpublished data, 1990); (2) comor¬ bid social phobia: social phobia with a comorbid major lifetime DIS/DSM-77I diagnosis; (3) social phobia as the only lifetime DIS/ DSM-III phobic disorder (to evaluate age at onset of social pho¬ bia; see Psychiatric Assessment); and (4) social phobia and his¬ tory of psychiatric treatment. because
=
diagnostic criteria.
Diagnostic Outcome Three hierarchical diagnostic groups were created for these analyses. The first group included all subjects with social pho¬ bia, excluding only those with comorbid schizophrenia (n 40). Unlike the ECA analysis of Bourdon et al,11 subjects with comor¬ bid schizophrenia were excluded here because the pervasive quality of schizophrenia and its associated social deficits could obscure the clinical relevance of comorbid social phobia and de¬ tract from reliability and validity of the social phobia diagnosis. The second group included all subjects with O1S/DSM-III disor¬ ders, excluding those with social phobia. The third group included all subjects with no OIS/DSM-II1 disorder (except sim¬ ple phobias). In subsequent analyses, we examined subgroups with (1) uncomplicated social phobia: social phobia as the only major lifetime D1S/DSM-III diagnosis. Included in this subgroup were subjects with comorbid simple phobia or dysthymia, =
Assessments were made of comorbidity with other lifetime DIS/DSM-7/7 major disorders (comorbidity) and of suicide at¬ tempts and suicidal ideation, financial dependency, and utiliza¬ tion of treatment (morbidity). Financial dependency was defined by current receipt of disability or welfare. Treatment utilization measures were based on lifetime use of treatment for problems with emotions, nerves, alcohol, other drugs, or mental health. Sources of treatment were categorized as psychiatric outpatient, psychiatric inpatient, emergency department, or general medi¬ cal. General medical care included help for an emotional prob¬ lem from medical physicians in private practice. Psychiatric out¬ patient care included help obtained from any of the following: a psychiatrist, psychologist, social worker, counselor, or other mental health specialist practicing at a mental health center or a psychiatric outpatient clinic at a general, psychiatric, or university-affiliated hospital. Neither financial dependency nor treatment utilization measures were limited to effects of social phobia per se.
Data
Analyses
multiway frequency tables describing rates of disorder by site and by sociodemographics include actual numbers of persons surveyed and their weighted percentage in the sam¬ ple. The weights employed adjust the data to reflect the census compositions of the four sites.33 Each sample case had a known probability of selection from the target population. A weight was assigned to each respondent to enable compen¬ sation for undersampling or oversampling when determining population prevalence. The statistical association between the dependent variables and subjects classified into diagnostic groups was analyzed by multiway frequency tables with raw percentages as well as logistic regression. The logistic regressions controlled for comorbidity and several demographic characteristics: gender, age The
(as a continuous variable), socioeconomic status (as a continuous variable with the use of a composite score derived from occupa¬ tional level, educational level, and household income), race (white, black, Hispanic, and other), and marital status (separated/divorced and other). Adjusted odds ratios (ORs) with 95% and 99% confidence in¬ tervals were derived from the logistic regressions.41 Adjusted ORs provide an index of the strength of the association between the diagnostic grouping variable described earlier and the qual¬ ity of life outcomes while controlling for demographic differ¬ ences. Statistical significance in these logistic regressions can generally be judged by the confidence interval; when it excludes 1, the risk can be said to be significant at a level of 5% for a 95% confidence interval. Given that the ECA was not a simple ran¬ dom sample, the SEs used to estimate the confidence intervals are underestimates.33 A reanalysis of the major findings reported herein employing suggested correction factors to the SEs33 revealed few substantive differences. RESULTS
Frequency of the Disorder Prevalence rates per 100 persons for lifetime D1S/DSM-III-
diagnosed social phobia at four ECA sites are presented in Table 1. The across-site (weighted lifetime prevalence rate) mean was
Downloaded From: http://archpsyc.jamanetwork.com/ by a New York University User on 05/31/2015
"Values are unweighted numbers (weighted percentages). Social phobia excludes subjects with comorbid schizophrenia.
2.4/100, and the
rate varied
somewhat between sites
P
sociodemographic and clinical features of social phobia were assessed in four US communities among more than 13 000 adults from the Epidemiologic Catchment Area study. Rates of social phobia were highest among women and persons who
were younger (age, 18 to 29 years), less educated, single, and of lower socioeconomic class. Mean
age at onset was 15.5 years, and first onsets after the age of 25 years were uncommon. Lifetime major comorbid disorders were present in 69% of subjects with social phobia and usually had onset after social phobia. When compared with persons with no psychiatric disorder, uncomplicated social phobia was associated with increased rates of suicidal ideation, financial dependency, and having sought medical treatment, but was not associated with higher rates of having made a suicide attempt or having sought treatment from a mental health professional. An increase in suicide attempts was found among subjects with social phobia overall, but this increase was mainly attributable to comorbid cases. Social phobia, in the absence of comorbidity, was associated with distress and impairment, yet was rarely treated by mental health professionals. The findings are compared and contrasted with prior reports from clinical samples.
(Arch Gen Psychiatry. 1992;49:282-288)
studies social in around the Prior Catchment Area of data found 6-month prevalences of DSM-III social phobia at two US sites of 0.9% to 1.7% for men and 1.5% to 2.6% for women,9 with overall 1-month, 6-month, and lifetime prevalences across four sites of 1.3%, 1.5%, and 2.8%, re¬
have examined the prevalence of world.1"8 Several phobia populations (ECA) study reports Epidemiologie 1
spectively.10 Social phobia in the US population has been further characterized by another ECA report11 that examined gender differences in the phobias. No significant gender differences in lifetime prevalence of social phobia or in age Accepted
publication June 12, 1991. From the Departments of Therapeutics (Drs Schneier and Liebowitz) and Clinical and Genetic Epidemiology (Drs Johnson and Weissman and Mr Hornig), New York State Psychiatric Institute, New York; and the Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY (Drs Schneier, Johnson, Liebowitz, and Weissman and Mr Hornig). tDr Johnson died January 10, 1992. Reprint requests to Anxiety Disorders Clinic, New York State Psychiatric Institute, 722 W 168th St, New York, NY 10032 (Dr Schneier).
for
Hornig;
found. The disorder was significantly less subjects over 65 years old than in subjects 18 to 24 years old. Among males it was less common in black men and in married men. Among females social phobia was significantly more common in divorced or separated at onset were common
women
in
and in
women
of low socioeconomic status.
Beyond these reports of prevalence and demographics, little has been reported about other characteristics of so¬ cial phobia in the general population. It is unclear to what extent these epidemiologically identified cases resemble the more extensively described social-phobic patients at¬ tending anxiety disorder clinics. Reported characteristics of the disorder based only on subjects with social phobia seeking treatment could represent selection for certain types of social phobia (eg, generalized type), greater im¬ pairment, higher or lower comorbidity, or greater access to mental health care. Few epidemiologie reports have examined impairment (social morbidity) or comorbidity in social phobia, and none have studied uncomplicated so¬ cial phobia or controlled for most comorbid disorders that may contribute to poor outcome. Several epidemiologie studies101225 that examined prevalence, age at onset, spe¬ cific anxiety symptoms, comorbidity, and treatmentseeking behavior have not reported findings for uncom¬ plicated social phobia or for social phobia separately from other phobic disorders, although clinical studies demon¬ strate differences in these features between social phobia, simple phobias, and agoraphobia.26"32 This article will examine several aspects of social pho¬ bia in the general population not reported in previous publications of ECA data, including measures of distress and morbidity (suicidal ideation, suicide attempts, finan¬ cial dependence), treatment utilization, and comorbidity with other psychiatric disorders. Findings will be com¬ pared with reports of clinical samples of social phobia. The
SUBJECTS AND METHODS
Epidemiologie Catchment Area The sample for this study is a subset of persons in the house¬ hold survey of the ECA program. The ECA study is an epidemi¬ ologie study of rates and risks for psychiatric disorders based on a probability sample of more than 18 000 adults aged 18 years and over, living in five US communities (New Haven, Conn; St Louis, Mo; Baltimore, Md; Durham, NC; and Los Angeles, Ca¬ lif). Response rates during the wave I interview ranged from 76% to 80%. A full description of the purpose, methods, and sampling frame can be found elsewhere.33"35
Downloaded From: http://archpsyc.jamanetwork.com/ by a New York University User on 05/31/2015
Each ECA site used the
Diagnostic
Interview Schedule dis¬
(DIS), which generated DSM-III diagnoses for the major
orders. A
core
set of
items,
including demographics
and
utilization, were also collected at all sites. The New Haven site, however, used version II of the DIS, which did treatment
not include social phobia items. Data from New Haven are not represented in this article, which is based on 13537 sub¬
jects
from the
remaining
four sites.
Comorbidity and Morbidity
Psychiatric Assessment The DIS is a highly structured interview, designed for use by lay interviewers in epidemiologie studies.36 The DIS includes a structured set of questions so that responses can be subjected to a computer algorithm to produce DSM-III psychiatric diagnoses. Classifications of pathologic features according to DSM-III crite¬ ria made via the interview questions of the DIS are referred to as DIS/DSM-ÍIÍ diagnoses. Subjects were told: Some people have phobias, that is, such a strong fear of some¬ thing or some situation that they try to avoid it, even though they
know there is no real danger. Have you ever had such an unrea¬ sonable fear of (—) that you tried to avoid it/them? Does having to avoid (—) interfere with your life or activities a lot? Subjects were asked these questions for a series of phobic sit¬ uations related to simple phobias and agoraphobia and for three social-phobic situations: (1) "eating in front of other peopleeither people you know or in public," (2) "speaking in front of a small group of people you know," and (3) "speaking to strang¬ ers or meeting new people." Subjects who had phobias of any of the above three situations were diagnosed as having DIS/ DSM-III social phobia. Age at onset was obtained for "any pho¬ bia," but in subjects with more than one phobic diagnosis, age at onset was not obtained for each phobic disorder separately (ie, social phobia, agoraphobia, or simple phobia). Age at onset was recorded in years, the range being 2 to 94 years. When subjects reported having social phobia their whole life, 2 years was recorded as age at onset. Discussions of the reliability and validity of the DIS in field surveys have appeared in several publications.37"42 A comparison was made of DIS diagnoses by lay interviewers and by psychi¬ atrists using a DSM-III checklist in 361 cases.37 The groups agreed on the presence of social phobia in 12 cases and the absence of social phobia in 319 cases, yielding an overall 92% agreement. In 15 cases each, one group diagnosed social phobia while the other did not, so prevalence estimates were the same in both groups. Rates of sensitivity and specificity were 44% and 96%, respec¬ tively ( .40, Yate's .61). Heizer et al37 suggested that a low score could be explained partly as a consequence of low base rates of the diagnosis, and low sensitivity could be partly a con¬ sequence of clustering of positive cases around the threshold for =
prior ECA analyses of subjects with simple phobia or dysthymia alone found no significant differences from subjects with no disorder (M.M.W., unpublished data, 1990); (2) comor¬ bid social phobia: social phobia with a comorbid major lifetime DIS/DSM-77I diagnosis; (3) social phobia as the only lifetime DIS/ DSM-III phobic disorder (to evaluate age at onset of social pho¬ bia; see Psychiatric Assessment); and (4) social phobia and his¬ tory of psychiatric treatment. because
=
diagnostic criteria.
Diagnostic Outcome Three hierarchical diagnostic groups were created for these analyses. The first group included all subjects with social pho¬ bia, excluding only those with comorbid schizophrenia (n 40). Unlike the ECA analysis of Bourdon et al,11 subjects with comor¬ bid schizophrenia were excluded here because the pervasive quality of schizophrenia and its associated social deficits could obscure the clinical relevance of comorbid social phobia and de¬ tract from reliability and validity of the social phobia diagnosis. The second group included all subjects with O1S/DSM-III disor¬ ders, excluding those with social phobia. The third group included all subjects with no OIS/DSM-II1 disorder (except sim¬ ple phobias). In subsequent analyses, we examined subgroups with (1) uncomplicated social phobia: social phobia as the only major lifetime D1S/DSM-III diagnosis. Included in this subgroup were subjects with comorbid simple phobia or dysthymia, =
Assessments were made of comorbidity with other lifetime DIS/DSM-7/7 major disorders (comorbidity) and of suicide at¬ tempts and suicidal ideation, financial dependency, and utiliza¬ tion of treatment (morbidity). Financial dependency was defined by current receipt of disability or welfare. Treatment utilization measures were based on lifetime use of treatment for problems with emotions, nerves, alcohol, other drugs, or mental health. Sources of treatment were categorized as psychiatric outpatient, psychiatric inpatient, emergency department, or general medi¬ cal. General medical care included help for an emotional prob¬ lem from medical physicians in private practice. Psychiatric out¬ patient care included help obtained from any of the following: a psychiatrist, psychologist, social worker, counselor, or other mental health specialist practicing at a mental health center or a psychiatric outpatient clinic at a general, psychiatric, or university-affiliated hospital. Neither financial dependency nor treatment utilization measures were limited to effects of social phobia per se.
Data
Analyses
multiway frequency tables describing rates of disorder by site and by sociodemographics include actual numbers of persons surveyed and their weighted percentage in the sam¬ ple. The weights employed adjust the data to reflect the census compositions of the four sites.33 Each sample case had a known probability of selection from the target population. A weight was assigned to each respondent to enable compen¬ sation for undersampling or oversampling when determining population prevalence. The statistical association between the dependent variables and subjects classified into diagnostic groups was analyzed by multiway frequency tables with raw percentages as well as logistic regression. The logistic regressions controlled for comorbidity and several demographic characteristics: gender, age The
(as a continuous variable), socioeconomic status (as a continuous variable with the use of a composite score derived from occupa¬ tional level, educational level, and household income), race (white, black, Hispanic, and other), and marital status (separated/divorced and other). Adjusted odds ratios (ORs) with 95% and 99% confidence in¬ tervals were derived from the logistic regressions.41 Adjusted ORs provide an index of the strength of the association between the diagnostic grouping variable described earlier and the qual¬ ity of life outcomes while controlling for demographic differ¬ ences. Statistical significance in these logistic regressions can generally be judged by the confidence interval; when it excludes 1, the risk can be said to be significant at a level of 5% for a 95% confidence interval. Given that the ECA was not a simple ran¬ dom sample, the SEs used to estimate the confidence intervals are underestimates.33 A reanalysis of the major findings reported herein employing suggested correction factors to the SEs33 revealed few substantive differences. RESULTS
Frequency of the Disorder Prevalence rates per 100 persons for lifetime D1S/DSM-III-
diagnosed social phobia at four ECA sites are presented in Table 1. The across-site (weighted lifetime prevalence rate) mean was
Downloaded From: http://archpsyc.jamanetwork.com/ by a New York University User on 05/31/2015
"Values are unweighted numbers (weighted percentages). Social phobia excludes subjects with comorbid schizophrenia.
2.4/100, and the
rate varied
somewhat between sites
P
