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Theoretical and observed subtypes of DSM-IV alcohol abuse and dependence in a general population sample
Drug and Alcohol Dependence 60 (2000) 287 – 293 www.elsevier.com/locate/drugalcdep
Theoretical and observed subtypes of DSM-IV alcohol abuse and dependence in a general population sample Bridget F. Grant * Di6ision of Biometry and Epidemiology, Suite 514, National Institute on Alcohol Abuse and Alcoholism, MSC-7003, 6000 Executi6e Boule6ard, Bethesda, MD 20892 -7003, USA Received 19 October 1999; received in revised form 15 January 2000; accepted 20 January 2000
Abstract The purpose of this study was to quantify the degree of heterogeneity of the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol abuse and dependence categories by comparing the number of theoretically predicted subtypes of each category with those observed in a nationally representative sample of the US general population. Among respondents classified with a past year diagnosis of abuse, only 11 (47.8%) of the 23 theoretically predicted subtypes of abuse were observed, while 53 (53.5%) of the 99 theoretically predicted subtypes of dependence were observed in this general population sample. Approximately 90% of the respondents classified with abuse could be represented by three subtypes of abuse and 70% of the respondents with current diagnoses of dependence could be characterized by six subtypes of dependence, indicating the relative homogeneity of both diagnostic categories. Sociodemographic differentials were also observed including the reduction in the number of observed subtypes of abuse and dependence with age as well as the larger numbers of subtypes associated with males and whites relative to females and blacks, respectively. Implications of these results are discussed in terms of increased physical morbidity and disruption of family life as persons with alcohol use disorders age, the potential role of physiological and impaired control over drinking indicators of dependence as critical features of the disorder, and the future need to examine the conceptual basis of the abuse category and to conduct longitudinal epidemiological research. © 2000 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Alcohol abuse; Alcohol dependence; Subtypes of alcohol dependence; Subtypes of alcohol abuse; Nosology
1. Introduction The heterogeneity of diagnostic categories appearing in psychiatric classification systems has been a matter of concern for many years (Wittenborn and Holzberg, 1951, 1953; Rotter, 1954). The definition of alcohol dependence appearing in the Diagnostic and Statistical Manual of Mental Disorders-Third Edition-Revised (DSM-III-R) (American Psychiatric Association, 1987) has been subject to similar criticism. The requirement that at least three of nine dependence criteria be met for a positive DSM-III-R diagnosis of dependence predicts the diversity of behaviors subsumed within its broad boundaries. Despite the defined inclusiveness of the DSM-III-R dependence construct, only one empirical study has * Tel.: +1-301-4437370; fax: + 1-301-4438614.
been conducted to assess its departure from homogeneity. In that study, the number of theoretical subtypes of dependence predicted from combinatorial theory was compared with the number of empirically observed subtypes of dependence (Grant et al., 1992). Forty-one percent (n= 189) of the theoretically predicted subtypes of alcohol dependence (n= 466) were observed in the general population sample, indicating that the category was indeed heterogeneous, but not as heterogeneous as predicted. Symptoms of alcohol dependence representing physiological dependence (i.e. tolerance and/or withdrawal) and impaired control over drinking also appeared as criteria in over 80% of all empirical subtypes of dependence regardless of gender, race or age. The purpose of this study is to utilize the methodology of Grant et al. (1992) to examine departures from homogeneity resulting from the broad and inclusive structure of the most current psychiatric classification
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B.F. Grant / Drug and Alcohol Dependence 60 (2000) 287–293
of alcohol dependence appearing in the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) (American Psychiatric Association, 1992) in a general population sample. Moving beyond the approach of Grant et al. (1992), the quantification of the degree of heterogeneity of the alcohol abuse category will also be examined by comparing the number of theoretically predicted subtypes of abuse to those empirically observed. Major empirical subtypes of alcohol abuse and dependence will be identified across important sociodemographic subgroups of the population with a view toward understanding the structure underlying these diagnostic categories. It will also be of interest in this study to quantify the potential reduction in heterogeneity of the dependence category resulting from the reduction of the total number of alcohol dependence criteria from nine in the DSM-III-R to seven in the DSM-IV.
2. Methods
2.1. Sample This study was based on the National Longitudinal Alcohol Epidemiologic Survey (NLAES), a national probability sample sponsored by the National Institute on Alcohol Abuse and Alcoholism. Fieldwork for the study was conducted by the United States Bureau of the Census in 1992. Direct face-to-face interviews were administered to 42 862 respondents, 18 years of age and older, residing in the noninstitutionalized population of the contiguous US, including the District of Columbia. Approximately 92% of the selected households participated in this survey while 97.4% of the randomly selected respondents in these households participated in this survey, yielding an overall response rate of 90%. The NLAES consisted of a complex multistage design which featured sampling of primary units with probability proportional to size and oversampling of the black and young adult (18 – 29 years) populations. The NLAES design has been described in detail elsewhere (Massey et al., 1989; Grant et al., 1994).
2.2. DSM-IV dependence and abuse measures DSM-IV alcohol use disorders were derived from the Alcohol Use Disorders and Associated Disabilities Interview Schedule (AUDADIS), a fully-structured psychiatric interview designed to be administered by trained lay interviewers (Grant and Hasin, 1992). The AUDADIS included an extensive list of symptom items that operationalized the DSM-IV criteria for alcohol abuse and dependence.
Respondents were classified with past year dependence if they met at least three of the seven DSM-IV criteria for dependence within the 1-year period preceding the interview: tolerance; withdrawal or avoidance of withdrawal; desire/attempts to cut down or stop drinking; much time spent on drinking, obtaining alcohol, or recovering from its effects; reduction/cessation of important activities in favor of drinking; impaired control; and continued drinking despite physical or psychological problems caused or exacerbated by drinking. Respondents were classified with past year alcohol abuse if they met at least one of the four DSM-IV criteria for abuse in the 1-year period preceding the interview; alcohol-related legal problems; continued drinking despite interpersonal problems; neglect of role responsibilities due to drinking; and drinking in hazardous situations. The AUDADIS diagnoses of past year alcohol abuse and dependence also satisfied the clustering and duration criteria of the DSM-IV definitions. The criteria of the DSM-IV require the clustering of symptoms of each diagnosis within the 1-year period preceding the interview in addition to associating duration qualifiers with certain abuse and dependence criteria. The duration qualifiers are defined in the DSM-IV as the repetitiveness with which symptoms must occur in order to be counted as positive towards a diagnosis. They are represented by the terms ‘recurrent’, and ‘persistent’ appearing in the description of the diagnostic criteria. The reliability of past year DSM-IV alcohol abuse and dependence diagnoses was 0.76 as ascertained from an independent test–retest study conducted in a general population sample (Grant et al., 1995).
2.3. Analysis All tables present percentages of empirically derived subtypes of alcohol abuse and dependence based on weighted data, accompanied by the unweighted number of subtypes upon which they are based. All analyses included respondents who were classified with current (i.e. past 12 month) diagnoses of alcohol abuse and/or dependence. Consistent with the DSM-IV definitions, the alcohol dependence group included respondents with and without additional diagnoses of abuse, while those classified with abuse diagnoses did not have diagnoses of alcohol dependence. Thus, the two groups were mutually exclusive. The total number and theoretical subtype of alcohol dependence was determined by the formula for combinatorials, [n!/(n − r!)r!], where n=7 (i.e. the total number of dependence criteria) and r=3–7, (i.e. the number of criteria that must be present above the cut-off for a positive diagnosis). For example, the number of potential subtypes for three out of seven dependence criteria can be calculated using the
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289
Table 1 Theoretical and observed subtypes of Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol abuse and dependence by number of criteria satisfied No. criteria satisfied
No. potential subtypes
No. observed subtypes
Percentage of total number of observed subtypes
Abuse 4 3 2 1 Total
1 12 6 4 23
0 3 4 4 11
0.0 1.2 15.1 83.7 100.0
Dependence 7 6 5 4 3 Total
1 7 21 35 35 99
1 3 7 14 28 53
4.7 6.0 14.0 24.7 50.6 100.0
aforementioned formula where n!= 7 × 6 × 5 ×4 × 3 × 2 × 1 and r!=3× 2 ×1. The same formulation was used to estimate the total number of theoretical subtypes of the alcohol abuse category, where n =4 (i.e. the total number of abuse criteria) and r = 1 – 4 (i.e. the number of criteria that must be present to achieve a diagnosis of abuse).
3. Results The prevalences of past year DSM-IV alcohol abuse and dependence in this general population sample were 3.03% (n= 1186) and 4.38% (n =1724), representing 5 628 000 and 8 132 000 Americans, respectively. As shown in Table 1, only 11 (47.8%) of the 23 predicted subtypes of abuse were observed in this general population sample. Of the 99 theoretically predicted subtypes of dependence, only 53 (53.5%) were empirically observed. The majority of subtypes of abuse (83.7%) contained only one positive criterion, while the majority of dependence subtypes consisted of three (50.6%) or four (24.7%) positive criteria. The number and percentage of empirically observed subtypes of alcohol abuse and dependence among sociodemographic groups of the population are presented in Table 2. Paralleling the distribution of the prevalence of abuse and dependence in the general population, more empirical subtypes were observed for males than females, whites than blacks, while the number of subtypes declined as a function of age. Table 3 focuses on the number and percentage of empirical subtypes of abuse and dependence containing each diagnostic criterion. The ‘drinking larger amounts or over longer periods than intended’ and ‘time spent in obtaining alcohol, drinking or recovering from its effects’ criteria were the two most prevalent single diagnostic criterion, appearing in 62.3% of all empirically
observed subtypes of dependence. The ‘drinking despite physical or psychological problems’ criterion was the least prevalent among the subtypes observed in this general population sample (45.3%). Interestingly, the two physiological indicators of dependence (i.e. tolerance and withdrawal), appeared together or alone in 43
Table 2 Number and percentage of empirical subtypes of Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol abuse and dependence by gender, race and age Diagnosis/characterstic
Abuse Total Gender Male Female Race White Black Age (in years) 18–29 30–44 45–64 65 and older Dependence Total Gender Male Female Race White Black Age (in years) 18–29 30–44 45–64 65 and older
No.
Percentage of total number of observed subtypes
11
100.00
10 9
90.9 81.8
11 8
100.0 72.7
11 9 7 3
100.0 81.8 63.6 27.3
53
100.0
52 36
98.1 67.9
51 29
96.2 54.7
40 41 31 18
75.5 77.4 58.5 40.0
B.F. Grant / Drug and Alcohol Dependence 60 (2000) 287–293
290
Table 3 Number and percentage of empirical subtypes of Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol abuse and dependence containing each diagnostic criteriona Criterion
Abuse Total Hazardous use Neglect of role Drinking despite interpersonal problems Legal problems Dependence Total Physiological dependence Tolerance Withdrawal/relief withdrawal Impaired control Larger amounts/longer period Desire/attempts to stop or cut down Time spent Important activities given up Drinking despite physical/psychological problem a
No.
Percent of total number of observed subtypes
11 7 5 5
100.0 63.6 45.5 45.5
4
36.4
53 43 26 28 42 33
100.0 81.2 49.1 52.8 79.3 62.3
26
49.1
33 30 24
62.3 56.6 45.3
Percentages based on weighted figures.
of the 53 or in 81.1% of all observed subtypes of dependence. ‘Hazardous use’ was the most prevalent abuse criterion appearing in 63.6% of all observed abuse subtypes, while ‘legal problems’ was the least prevalent criterion (36.4%). While examining the percentage of subtypes containing each criterion is informative, it can tell us very little about the most prevalent subtypes observed in this general population sample. For example, a particular criterion can appear in a majority of observed subtypes, but most of those subtypes may be of extremely low prevalence. To address this issue, the most prevalent subtypes of abuse and dependence among diagnosed respondents were examined. Fig. 1 shows the three most prevalent subtypes of abuse that together classified approximately 90% of all respondents with abuse diagnoses. Overall, the most prevalent subtype of abuse consisted of one criterion, ‘hazardous use’, classifying 66.9% of all abusers, followed in magnitude by the ‘neglect of role’ subtype and the combined ‘neglect of role/hazardous use’ subtype, each characterizing 10.6% of all respondents classified with abuse. The remaining eight of the total 11 subtypes of abuse not shown in Fig. 1 were generally associated with prevalences of less than 1% of the total number of observed subtypes. With the exception of the respondents 45 years of age and older, the subtypes of greatest preva-
lence noted for the total sample were consistent for males and females, blacks and whites and among respondents in the two youngest age groups. For respondents aged 45 years and older the ‘drinking despite interpersonal problems’ criterion replaced the ‘neglect of role’ criterion in the second and third most prevalent subtypes of abuse. Fig. 2 shows the six most prevalent subtypes of alcohol dependence by gender, race and age. For the total sample, the three most prevalent subtypes each classified between 13 and 15% of all respondents with dependence diagnoses. The fourth and fifth most prevalent subtypes each accounted for approximately 9% of all respondents, while the sixth most prevalent subtype described 6% of all respondents classified with dependence. With one exception, each of the six most prevalent subtypes of dependence contained at least one physiological indicator of dependence (i.e. tolerance and/or withdrawal) and at least one indicator of impaired control over drinking (i.e. drinking more or longer than intended and/or desire or unsuccessful attempts to cut down or stop drinking). The remaining subtypes of dependence (n= 47) not shown in Fig. 2 were generally each associated with prevalences of less 1% of the total number of observed subtypes. Although the six most prevalent subtypes noted for the overall sample were consistent across sociodemographic subgroups of the population, there was a departure noted for the 65 years and older age group. In that age group, the most prevalent subtype of dependence (14.7%) consisted of the two impaired control indicators, but unlike the other groups, the ‘tolerance’ criterion was replaced with the ‘drinking despite physical or psychological problems’ criterion. Most interestingly, all 53 observed subtypes of dependence contained at least one indicator of physiological dependence or impaired control over drinking.
4. Discussion Forty-eight percent (11/23) of the theoretical subtypes of DSM-IV abuse and 54% (53/99) of the theoretical subtypes of DSM-IV dependence were observed in this general population sample. These findings indicate that both diagnostic categories are heterogeneous, but not as heterogeneous as theoretically predicted. In previous work of Grant et al. (1992) in this area, 41% (n =189) of the theoretical subtypes of DSM-III-R alcohol dependence were observed in a similar general population sample. Recall that the DSM-III-R required at least three positive dependence criteria of nine in order to achieve a dependence diagnosis while the DSM-IV requires at least three positive criteria of seven. Taken together, these results indicate that a reduction in the total number of dependence criteria
B.F. Grant / Drug and Alcohol Dependence 60 (2000) 287–293
from DSM-III-R to DSM-IV has not lead to any significant reduction in heterogeneity of the alcohol dependence category. The sociodemographic differential observed in the number of empirical subtypes of alcohol abuse and dependence shown in this sample may be, in part, attributed to death from competing causes among the elderly as the rate of common disabling medical problems, such as arthritis, cardiovascular disease, hypertension and stroke, and diabetes rise with age. Heavy drinking also increases the risk of numerous severe medical problems, most notably liver cirrhosis, cardiomyopathy, malnutrition and chronic pancreatitis. These explanations are supported by the finding that
291
the number of empirical subtypes of abuse and dependence decreased with age. Unlike the other sociodemographic subgroups of the population, the most prevalent subtype of dependence among respondents 65 years and older contained the ‘drinking despite physical or psychological problems’ criterion, again indicating that the physical morbidity from alcoholism may indeed be taking its toll as persons with alcohol use disorders age. The results of this study also implicated reporting biases noted in other studies (Makela, 1978; Knupfer, 1982), i.e. females and blacks may be less likely to report, but not to experience, alcohol abuse and dependence symptoms given the more severe societal con-
Fig. 1. Three most prevalent subtypes of Diagnostical and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol abuse as a function of gender, race and age.
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B.F. Grant / Drug and Alcohol Dependence 60 (2000) 287–293
Fig. 2. Six most prevalent subtypes of Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol dependence as a function of gender, race and age.
straints on excessive drinking in these subgroups of the population. Other findings suggest that, as people age, those with alcohol use disorders often have severe disruptions in family life. Unlike the other sociodemographic groups, the second and third most prevalent subtypes of alcohol abuse included the ‘drinking despite interpersonal problems’ criterion. This result may signal separation, divorce, or lack of contact with children frequently seen among older persons with alcohol use disorders. Since adult offspring are at greater risk themselves of abusing alcohol, they can also become supporters of continuing and excessive drinking patterns in
aging parents, thereby reinforcing severe disruptions in interpersonal relationships. Similar to the findings of Grant et al. (1992), criteria of alcohol dependence representing physiological dependence and impaired control over drinking were identified as playing a key role in the configuration of empirical subtypes, appearing in approximately 80% of all reported subtypes regardless of age, race or sex. These findings suggest that these criteria may be necessary, but not entirely sufficient, to identify individuals as belonging to the dependence category. Thus, these results support one aspect of the DSM-IV definition of
B.F. Grant / Drug and Alcohol Dependence 60 (2000) 287–293
alcohol dependence that provides for the subtyping of dependence as physiological and nonphysiological. It should be noted, however, that the observed subtypes of dependence for other drugs may differ from those of alcohol depending on their physiological addiction liability. When viewed in terms of overall prevalence of each subtype, and not in terms of the total number of observed subtypes, the striking degree of homogeneity of both DSM-IV abuse and dependence categories becomes evident. Approximately 90% of the respondents classified with abuse could be characterized by three subtypes of dependence, while almost 70% of all respondents classified with alcohol dependence could be described by six subtypes of dependence. These are remarkable findings when viewed within the context of the sheer number of theoretically predicted subtypes of DSM-IV alcohol abuse and dependence, that is, 23 and 99, respectively. With respect to alcohol abuse, hazardous use was the single most prevalent subtype reported among abusers. This result suggests that, at the conceptual level, the abuse construct may indeed be measuring a dimension of hazardous drinking. Future research directed towards defining and examining the conceptual basis of the DSM-IV alcohol abuse category might help clarify this issue. Considering that almost 70% of all respondents classified with a dependence diagnosis could be characterized by only six subtypes of dependence speaks not only to the homogeneity of the category but also helps define what might be considered the critical features of the disorder. Not only did the six most prevalent subtypes of alcohol dependence contain a physiological and impaired control over drinking criteria, but all 53 observed subtypes of dependence contained at least one of these criteria. Clearly, both the physiological indicators of dependence might be candidates for the defining features of dependence. Whether the definition of dependence should be altered to require tolerance and/or withdrawal should be an issue subject to further investigation. Although this study has provided an increased understanding of the structure underlying the DSM-IV alcohol abuse and dependence categories and their degree
.
293
of homogeneity, there are limits to the strength of conclusions drawn from cross-sectional data. Future research should include longitudinal epidemiological research to define the appearance of dependence indicators over time. Longitudinal research can also establish the validity of the DSM-IV categories by identifying those abuse and dependence indicators that are most predictive of etiology, future course and treatment outcome.
References American Psychiatric Association, 1987. Diagnostic and Statistical Manual of Mental Disorders, 3rd Edition, Revised (DSM-III-R). American Psychiatric Association, Washington, D.C. American Psychiatric Association, 1992. Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, (DSM-IV). American Psychiatric Association, Washington, D.C. Grant, B.F., Hasin, D., 1992. The Alcohol Use Disorder and Associated Disabilities Interview Schedule. National Institute on Alcohol Abuse and Alcoholism, Rockville, MD. Grant, B.F., Chou, S.P., Pickering, R., Dawson, D.A., 1992. Empirical subtypes of DSM-III-R alcohol dependence: United States, 1988. Drug Alcohol Depend. 30, 75 – 84. Grant, B.F., Harford, T.C., Dawson, D.A., Chou, P., Dufour, M., Pickering, R., 1994. Prevalence of DSM-IV alcohol abuse and dependence. Alcohol Health Res. World 18, 243 – 248. Grant, B.F., Harford, T.C., Dawson, D.A., Chou, P.S., Pickering, R.P., 1995. The alcohol use disorders and associated disabilities interview schedule (AUDADIS): reliability of alcohol and drug modules in a general population sample. Drug Alcohol Depend. 39, 37 – 44. Knupfer, G., 1982. Problems associated with drunkenness in women: Some research issues. In: National Institute on Alcohol Abuse and Alcoholism (Ed.), Special Populations Issue, Alcohol and Health Monogrph No. 4, Government Printing Office, Washington, DC, pp. 3 – 39. Makela, K., 1978. Level of consumption and social consequences of drinking. In: Israel, Y., Glazer, F.B., Kalant, H., Popham, R.E., Schmidt, W., Smart, R.G. (Eds.), Recent Advances in Alcohol and Drug Problems. Plenum Press, New York, pp. 303–348. Massey, J.T., Moore, T.F., Parsons, V.L., Tadros, W., 1989. Design and Estimation for the National Health Survey, 1985–1994. National Center for Health Statistics, Hyattsville, MD. Rotter, J., 1954. Social Learning and Clinical Psychology. PrenticeHall, New York. Wittenborn, J., Holzberg, J., 1951. The reliability of psychiatric diagnosis. J. Consult. Psychol. 15, 372 – 382. Wittenborn, J., Holzberg, J., 1953. A study in psychiatric classification. Gen. Psychol. Monogr. 47, 237 – 253.
Theoretical and observed subtypes of DSM-IV alcohol abuse and dependence in a general population sample Bridget F. Grant * Di6ision of Biometry and Epidemiology, Suite 514, National Institute on Alcohol Abuse and Alcoholism, MSC-7003, 6000 Executi6e Boule6ard, Bethesda, MD 20892 -7003, USA Received 19 October 1999; received in revised form 15 January 2000; accepted 20 January 2000
Abstract The purpose of this study was to quantify the degree of heterogeneity of the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol abuse and dependence categories by comparing the number of theoretically predicted subtypes of each category with those observed in a nationally representative sample of the US general population. Among respondents classified with a past year diagnosis of abuse, only 11 (47.8%) of the 23 theoretically predicted subtypes of abuse were observed, while 53 (53.5%) of the 99 theoretically predicted subtypes of dependence were observed in this general population sample. Approximately 90% of the respondents classified with abuse could be represented by three subtypes of abuse and 70% of the respondents with current diagnoses of dependence could be characterized by six subtypes of dependence, indicating the relative homogeneity of both diagnostic categories. Sociodemographic differentials were also observed including the reduction in the number of observed subtypes of abuse and dependence with age as well as the larger numbers of subtypes associated with males and whites relative to females and blacks, respectively. Implications of these results are discussed in terms of increased physical morbidity and disruption of family life as persons with alcohol use disorders age, the potential role of physiological and impaired control over drinking indicators of dependence as critical features of the disorder, and the future need to examine the conceptual basis of the abuse category and to conduct longitudinal epidemiological research. © 2000 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Alcohol abuse; Alcohol dependence; Subtypes of alcohol dependence; Subtypes of alcohol abuse; Nosology
1. Introduction The heterogeneity of diagnostic categories appearing in psychiatric classification systems has been a matter of concern for many years (Wittenborn and Holzberg, 1951, 1953; Rotter, 1954). The definition of alcohol dependence appearing in the Diagnostic and Statistical Manual of Mental Disorders-Third Edition-Revised (DSM-III-R) (American Psychiatric Association, 1987) has been subject to similar criticism. The requirement that at least three of nine dependence criteria be met for a positive DSM-III-R diagnosis of dependence predicts the diversity of behaviors subsumed within its broad boundaries. Despite the defined inclusiveness of the DSM-III-R dependence construct, only one empirical study has * Tel.: +1-301-4437370; fax: + 1-301-4438614.
been conducted to assess its departure from homogeneity. In that study, the number of theoretical subtypes of dependence predicted from combinatorial theory was compared with the number of empirically observed subtypes of dependence (Grant et al., 1992). Forty-one percent (n= 189) of the theoretically predicted subtypes of alcohol dependence (n= 466) were observed in the general population sample, indicating that the category was indeed heterogeneous, but not as heterogeneous as predicted. Symptoms of alcohol dependence representing physiological dependence (i.e. tolerance and/or withdrawal) and impaired control over drinking also appeared as criteria in over 80% of all empirical subtypes of dependence regardless of gender, race or age. The purpose of this study is to utilize the methodology of Grant et al. (1992) to examine departures from homogeneity resulting from the broad and inclusive structure of the most current psychiatric classification
0376-8716/00/$ - see front matter © 2000 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 3 7 6 - 8 7 1 6 ( 0 0 ) 0 0 1 1 5 - 0
288
B.F. Grant / Drug and Alcohol Dependence 60 (2000) 287–293
of alcohol dependence appearing in the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) (American Psychiatric Association, 1992) in a general population sample. Moving beyond the approach of Grant et al. (1992), the quantification of the degree of heterogeneity of the alcohol abuse category will also be examined by comparing the number of theoretically predicted subtypes of abuse to those empirically observed. Major empirical subtypes of alcohol abuse and dependence will be identified across important sociodemographic subgroups of the population with a view toward understanding the structure underlying these diagnostic categories. It will also be of interest in this study to quantify the potential reduction in heterogeneity of the dependence category resulting from the reduction of the total number of alcohol dependence criteria from nine in the DSM-III-R to seven in the DSM-IV.
2. Methods
2.1. Sample This study was based on the National Longitudinal Alcohol Epidemiologic Survey (NLAES), a national probability sample sponsored by the National Institute on Alcohol Abuse and Alcoholism. Fieldwork for the study was conducted by the United States Bureau of the Census in 1992. Direct face-to-face interviews were administered to 42 862 respondents, 18 years of age and older, residing in the noninstitutionalized population of the contiguous US, including the District of Columbia. Approximately 92% of the selected households participated in this survey while 97.4% of the randomly selected respondents in these households participated in this survey, yielding an overall response rate of 90%. The NLAES consisted of a complex multistage design which featured sampling of primary units with probability proportional to size and oversampling of the black and young adult (18 – 29 years) populations. The NLAES design has been described in detail elsewhere (Massey et al., 1989; Grant et al., 1994).
2.2. DSM-IV dependence and abuse measures DSM-IV alcohol use disorders were derived from the Alcohol Use Disorders and Associated Disabilities Interview Schedule (AUDADIS), a fully-structured psychiatric interview designed to be administered by trained lay interviewers (Grant and Hasin, 1992). The AUDADIS included an extensive list of symptom items that operationalized the DSM-IV criteria for alcohol abuse and dependence.
Respondents were classified with past year dependence if they met at least three of the seven DSM-IV criteria for dependence within the 1-year period preceding the interview: tolerance; withdrawal or avoidance of withdrawal; desire/attempts to cut down or stop drinking; much time spent on drinking, obtaining alcohol, or recovering from its effects; reduction/cessation of important activities in favor of drinking; impaired control; and continued drinking despite physical or psychological problems caused or exacerbated by drinking. Respondents were classified with past year alcohol abuse if they met at least one of the four DSM-IV criteria for abuse in the 1-year period preceding the interview; alcohol-related legal problems; continued drinking despite interpersonal problems; neglect of role responsibilities due to drinking; and drinking in hazardous situations. The AUDADIS diagnoses of past year alcohol abuse and dependence also satisfied the clustering and duration criteria of the DSM-IV definitions. The criteria of the DSM-IV require the clustering of symptoms of each diagnosis within the 1-year period preceding the interview in addition to associating duration qualifiers with certain abuse and dependence criteria. The duration qualifiers are defined in the DSM-IV as the repetitiveness with which symptoms must occur in order to be counted as positive towards a diagnosis. They are represented by the terms ‘recurrent’, and ‘persistent’ appearing in the description of the diagnostic criteria. The reliability of past year DSM-IV alcohol abuse and dependence diagnoses was 0.76 as ascertained from an independent test–retest study conducted in a general population sample (Grant et al., 1995).
2.3. Analysis All tables present percentages of empirically derived subtypes of alcohol abuse and dependence based on weighted data, accompanied by the unweighted number of subtypes upon which they are based. All analyses included respondents who were classified with current (i.e. past 12 month) diagnoses of alcohol abuse and/or dependence. Consistent with the DSM-IV definitions, the alcohol dependence group included respondents with and without additional diagnoses of abuse, while those classified with abuse diagnoses did not have diagnoses of alcohol dependence. Thus, the two groups were mutually exclusive. The total number and theoretical subtype of alcohol dependence was determined by the formula for combinatorials, [n!/(n − r!)r!], where n=7 (i.e. the total number of dependence criteria) and r=3–7, (i.e. the number of criteria that must be present above the cut-off for a positive diagnosis). For example, the number of potential subtypes for three out of seven dependence criteria can be calculated using the
B.F. Grant / Drug and Alcohol Dependence 60 (2000) 287–293
289
Table 1 Theoretical and observed subtypes of Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol abuse and dependence by number of criteria satisfied No. criteria satisfied
No. potential subtypes
No. observed subtypes
Percentage of total number of observed subtypes
Abuse 4 3 2 1 Total
1 12 6 4 23
0 3 4 4 11
0.0 1.2 15.1 83.7 100.0
Dependence 7 6 5 4 3 Total
1 7 21 35 35 99
1 3 7 14 28 53
4.7 6.0 14.0 24.7 50.6 100.0
aforementioned formula where n!= 7 × 6 × 5 ×4 × 3 × 2 × 1 and r!=3× 2 ×1. The same formulation was used to estimate the total number of theoretical subtypes of the alcohol abuse category, where n =4 (i.e. the total number of abuse criteria) and r = 1 – 4 (i.e. the number of criteria that must be present to achieve a diagnosis of abuse).
3. Results The prevalences of past year DSM-IV alcohol abuse and dependence in this general population sample were 3.03% (n= 1186) and 4.38% (n =1724), representing 5 628 000 and 8 132 000 Americans, respectively. As shown in Table 1, only 11 (47.8%) of the 23 predicted subtypes of abuse were observed in this general population sample. Of the 99 theoretically predicted subtypes of dependence, only 53 (53.5%) were empirically observed. The majority of subtypes of abuse (83.7%) contained only one positive criterion, while the majority of dependence subtypes consisted of three (50.6%) or four (24.7%) positive criteria. The number and percentage of empirically observed subtypes of alcohol abuse and dependence among sociodemographic groups of the population are presented in Table 2. Paralleling the distribution of the prevalence of abuse and dependence in the general population, more empirical subtypes were observed for males than females, whites than blacks, while the number of subtypes declined as a function of age. Table 3 focuses on the number and percentage of empirical subtypes of abuse and dependence containing each diagnostic criterion. The ‘drinking larger amounts or over longer periods than intended’ and ‘time spent in obtaining alcohol, drinking or recovering from its effects’ criteria were the two most prevalent single diagnostic criterion, appearing in 62.3% of all empirically
observed subtypes of dependence. The ‘drinking despite physical or psychological problems’ criterion was the least prevalent among the subtypes observed in this general population sample (45.3%). Interestingly, the two physiological indicators of dependence (i.e. tolerance and withdrawal), appeared together or alone in 43
Table 2 Number and percentage of empirical subtypes of Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol abuse and dependence by gender, race and age Diagnosis/characterstic
Abuse Total Gender Male Female Race White Black Age (in years) 18–29 30–44 45–64 65 and older Dependence Total Gender Male Female Race White Black Age (in years) 18–29 30–44 45–64 65 and older
No.
Percentage of total number of observed subtypes
11
100.00
10 9
90.9 81.8
11 8
100.0 72.7
11 9 7 3
100.0 81.8 63.6 27.3
53
100.0
52 36
98.1 67.9
51 29
96.2 54.7
40 41 31 18
75.5 77.4 58.5 40.0
B.F. Grant / Drug and Alcohol Dependence 60 (2000) 287–293
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Table 3 Number and percentage of empirical subtypes of Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol abuse and dependence containing each diagnostic criteriona Criterion
Abuse Total Hazardous use Neglect of role Drinking despite interpersonal problems Legal problems Dependence Total Physiological dependence Tolerance Withdrawal/relief withdrawal Impaired control Larger amounts/longer period Desire/attempts to stop or cut down Time spent Important activities given up Drinking despite physical/psychological problem a
No.
Percent of total number of observed subtypes
11 7 5 5
100.0 63.6 45.5 45.5
4
36.4
53 43 26 28 42 33
100.0 81.2 49.1 52.8 79.3 62.3
26
49.1
33 30 24
62.3 56.6 45.3
Percentages based on weighted figures.
of the 53 or in 81.1% of all observed subtypes of dependence. ‘Hazardous use’ was the most prevalent abuse criterion appearing in 63.6% of all observed abuse subtypes, while ‘legal problems’ was the least prevalent criterion (36.4%). While examining the percentage of subtypes containing each criterion is informative, it can tell us very little about the most prevalent subtypes observed in this general population sample. For example, a particular criterion can appear in a majority of observed subtypes, but most of those subtypes may be of extremely low prevalence. To address this issue, the most prevalent subtypes of abuse and dependence among diagnosed respondents were examined. Fig. 1 shows the three most prevalent subtypes of abuse that together classified approximately 90% of all respondents with abuse diagnoses. Overall, the most prevalent subtype of abuse consisted of one criterion, ‘hazardous use’, classifying 66.9% of all abusers, followed in magnitude by the ‘neglect of role’ subtype and the combined ‘neglect of role/hazardous use’ subtype, each characterizing 10.6% of all respondents classified with abuse. The remaining eight of the total 11 subtypes of abuse not shown in Fig. 1 were generally associated with prevalences of less than 1% of the total number of observed subtypes. With the exception of the respondents 45 years of age and older, the subtypes of greatest preva-
lence noted for the total sample were consistent for males and females, blacks and whites and among respondents in the two youngest age groups. For respondents aged 45 years and older the ‘drinking despite interpersonal problems’ criterion replaced the ‘neglect of role’ criterion in the second and third most prevalent subtypes of abuse. Fig. 2 shows the six most prevalent subtypes of alcohol dependence by gender, race and age. For the total sample, the three most prevalent subtypes each classified between 13 and 15% of all respondents with dependence diagnoses. The fourth and fifth most prevalent subtypes each accounted for approximately 9% of all respondents, while the sixth most prevalent subtype described 6% of all respondents classified with dependence. With one exception, each of the six most prevalent subtypes of dependence contained at least one physiological indicator of dependence (i.e. tolerance and/or withdrawal) and at least one indicator of impaired control over drinking (i.e. drinking more or longer than intended and/or desire or unsuccessful attempts to cut down or stop drinking). The remaining subtypes of dependence (n= 47) not shown in Fig. 2 were generally each associated with prevalences of less 1% of the total number of observed subtypes. Although the six most prevalent subtypes noted for the overall sample were consistent across sociodemographic subgroups of the population, there was a departure noted for the 65 years and older age group. In that age group, the most prevalent subtype of dependence (14.7%) consisted of the two impaired control indicators, but unlike the other groups, the ‘tolerance’ criterion was replaced with the ‘drinking despite physical or psychological problems’ criterion. Most interestingly, all 53 observed subtypes of dependence contained at least one indicator of physiological dependence or impaired control over drinking.
4. Discussion Forty-eight percent (11/23) of the theoretical subtypes of DSM-IV abuse and 54% (53/99) of the theoretical subtypes of DSM-IV dependence were observed in this general population sample. These findings indicate that both diagnostic categories are heterogeneous, but not as heterogeneous as theoretically predicted. In previous work of Grant et al. (1992) in this area, 41% (n =189) of the theoretical subtypes of DSM-III-R alcohol dependence were observed in a similar general population sample. Recall that the DSM-III-R required at least three positive dependence criteria of nine in order to achieve a dependence diagnosis while the DSM-IV requires at least three positive criteria of seven. Taken together, these results indicate that a reduction in the total number of dependence criteria
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from DSM-III-R to DSM-IV has not lead to any significant reduction in heterogeneity of the alcohol dependence category. The sociodemographic differential observed in the number of empirical subtypes of alcohol abuse and dependence shown in this sample may be, in part, attributed to death from competing causes among the elderly as the rate of common disabling medical problems, such as arthritis, cardiovascular disease, hypertension and stroke, and diabetes rise with age. Heavy drinking also increases the risk of numerous severe medical problems, most notably liver cirrhosis, cardiomyopathy, malnutrition and chronic pancreatitis. These explanations are supported by the finding that
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the number of empirical subtypes of abuse and dependence decreased with age. Unlike the other sociodemographic subgroups of the population, the most prevalent subtype of dependence among respondents 65 years and older contained the ‘drinking despite physical or psychological problems’ criterion, again indicating that the physical morbidity from alcoholism may indeed be taking its toll as persons with alcohol use disorders age. The results of this study also implicated reporting biases noted in other studies (Makela, 1978; Knupfer, 1982), i.e. females and blacks may be less likely to report, but not to experience, alcohol abuse and dependence symptoms given the more severe societal con-
Fig. 1. Three most prevalent subtypes of Diagnostical and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol abuse as a function of gender, race and age.
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Fig. 2. Six most prevalent subtypes of Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol dependence as a function of gender, race and age.
straints on excessive drinking in these subgroups of the population. Other findings suggest that, as people age, those with alcohol use disorders often have severe disruptions in family life. Unlike the other sociodemographic groups, the second and third most prevalent subtypes of alcohol abuse included the ‘drinking despite interpersonal problems’ criterion. This result may signal separation, divorce, or lack of contact with children frequently seen among older persons with alcohol use disorders. Since adult offspring are at greater risk themselves of abusing alcohol, they can also become supporters of continuing and excessive drinking patterns in
aging parents, thereby reinforcing severe disruptions in interpersonal relationships. Similar to the findings of Grant et al. (1992), criteria of alcohol dependence representing physiological dependence and impaired control over drinking were identified as playing a key role in the configuration of empirical subtypes, appearing in approximately 80% of all reported subtypes regardless of age, race or sex. These findings suggest that these criteria may be necessary, but not entirely sufficient, to identify individuals as belonging to the dependence category. Thus, these results support one aspect of the DSM-IV definition of
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alcohol dependence that provides for the subtyping of dependence as physiological and nonphysiological. It should be noted, however, that the observed subtypes of dependence for other drugs may differ from those of alcohol depending on their physiological addiction liability. When viewed in terms of overall prevalence of each subtype, and not in terms of the total number of observed subtypes, the striking degree of homogeneity of both DSM-IV abuse and dependence categories becomes evident. Approximately 90% of the respondents classified with abuse could be characterized by three subtypes of dependence, while almost 70% of all respondents classified with alcohol dependence could be described by six subtypes of dependence. These are remarkable findings when viewed within the context of the sheer number of theoretically predicted subtypes of DSM-IV alcohol abuse and dependence, that is, 23 and 99, respectively. With respect to alcohol abuse, hazardous use was the single most prevalent subtype reported among abusers. This result suggests that, at the conceptual level, the abuse construct may indeed be measuring a dimension of hazardous drinking. Future research directed towards defining and examining the conceptual basis of the DSM-IV alcohol abuse category might help clarify this issue. Considering that almost 70% of all respondents classified with a dependence diagnosis could be characterized by only six subtypes of dependence speaks not only to the homogeneity of the category but also helps define what might be considered the critical features of the disorder. Not only did the six most prevalent subtypes of alcohol dependence contain a physiological and impaired control over drinking criteria, but all 53 observed subtypes of dependence contained at least one of these criteria. Clearly, both the physiological indicators of dependence might be candidates for the defining features of dependence. Whether the definition of dependence should be altered to require tolerance and/or withdrawal should be an issue subject to further investigation. Although this study has provided an increased understanding of the structure underlying the DSM-IV alcohol abuse and dependence categories and their degree
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of homogeneity, there are limits to the strength of conclusions drawn from cross-sectional data. Future research should include longitudinal epidemiological research to define the appearance of dependence indicators over time. Longitudinal research can also establish the validity of the DSM-IV categories by identifying those abuse and dependence indicators that are most predictive of etiology, future course and treatment outcome.
References American Psychiatric Association, 1987. Diagnostic and Statistical Manual of Mental Disorders, 3rd Edition, Revised (DSM-III-R). American Psychiatric Association, Washington, D.C. American Psychiatric Association, 1992. Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, (DSM-IV). American Psychiatric Association, Washington, D.C. Grant, B.F., Hasin, D., 1992. The Alcohol Use Disorder and Associated Disabilities Interview Schedule. National Institute on Alcohol Abuse and Alcoholism, Rockville, MD. Grant, B.F., Chou, S.P., Pickering, R., Dawson, D.A., 1992. Empirical subtypes of DSM-III-R alcohol dependence: United States, 1988. Drug Alcohol Depend. 30, 75 – 84. Grant, B.F., Harford, T.C., Dawson, D.A., Chou, P., Dufour, M., Pickering, R., 1994. Prevalence of DSM-IV alcohol abuse and dependence. Alcohol Health Res. World 18, 243 – 248. Grant, B.F., Harford, T.C., Dawson, D.A., Chou, P.S., Pickering, R.P., 1995. The alcohol use disorders and associated disabilities interview schedule (AUDADIS): reliability of alcohol and drug modules in a general population sample. Drug Alcohol Depend. 39, 37 – 44. Knupfer, G., 1982. Problems associated with drunkenness in women: Some research issues. In: National Institute on Alcohol Abuse and Alcoholism (Ed.), Special Populations Issue, Alcohol and Health Monogrph No. 4, Government Printing Office, Washington, DC, pp. 3 – 39. Makela, K., 1978. Level of consumption and social consequences of drinking. In: Israel, Y., Glazer, F.B., Kalant, H., Popham, R.E., Schmidt, W., Smart, R.G. (Eds.), Recent Advances in Alcohol and Drug Problems. Plenum Press, New York, pp. 303–348. Massey, J.T., Moore, T.F., Parsons, V.L., Tadros, W., 1989. Design and Estimation for the National Health Survey, 1985–1994. National Center for Health Statistics, Hyattsville, MD. Rotter, J., 1954. Social Learning and Clinical Psychology. PrenticeHall, New York. Wittenborn, J., Holzberg, J., 1951. The reliability of psychiatric diagnosis. J. Consult. Psychol. 15, 372 – 382. Wittenborn, J., Holzberg, J., 1953. A study in psychiatric classification. Gen. Psychol. Monogr. 47, 237 – 253.