Treatment-naive active alcoholics have greater psychiatric comorbidity than normal controls but less than treated abstinent alcoholics

Abstract

Background

Most alcoholism research in the U.S. uses convenience samples of treated alcoholics. The findings from treated samples have traditionally been applied to all alcoholics, including the 75% of alcoholics who are untreated. Improper generalization from select samples to an entire population is called ‘Berkson's fallacy’. We compared untreated versus treated alcoholics, in order to ascertain whether both groups belonged to the same population with regard to psychiatric comorbidity.

Methods

We compared psychiatric comorbidity in 1) active treatment-naive alcoholics (TNA; n = 86) 2) treated long-term abstinent alcoholics (TAA; n = 52) and 3) non-alcoholic controls (NAC; n = 118). We examined lifetime and current diagnoses, lifetime symptom counts, and psychological measures in the anxiety, mood and externalizing disorder domains.

Results

TNA did not differ from NAC in psychiatric diagnosis rates, were abnormal compared to NAC on all psychological measures, had more externalizing symptoms than NAC, and showed a strong trend for men to have more symptoms in the mood and anxiety domains. TAA compared to TNA had higher diagnosis rates (all domains), symptom counts (all domains), and psychological measures of deviance proneness, but were comparable to TNA on anxiety and mood psychological measures.

Conclusions

The abnormal thinking (psychological measures) in TNA (versus NAC) does not extend to behavior (symptoms) to the degree that it does in TAA. These results underline the importance of the use of subdiagnostic measures of psychiatric comorbidity in studies of alcoholics. The finding of lesser comorbidity in TNA versus TAA confirms the presence of Berkson's fallacy in generalizing from treated samples to all alcoholics.

Introduction

In 2005, we showed that treated alcoholics are not simply former untreated alcoholics observed later in the progress of their disease. Treated alcoholics are a different population than untreated alcoholics; they drink more even at the beginning of their first heavy use of alcohol (Fein and Landman, 2005). This suggests more severe alcoholism in the treated alcoholics. This finding has far-reaching implications for two reasons: (1) it confirms the presence of Berkson's fallacy in the field of alcoholism research, and (2) it adds significant information to the current effort to classify alcoholics into clinically meaningful subgroups.

Most alcoholism research uses convenience samples of alcoholics in treatment, or shortly after treatment. Improper generalization from select samples to an entire population is called ‘Berkson's fallacy’; an example would be generalization from the 25% of alcoholics who have received treatment (Dawson et al., 2005) to the 75% of alcoholics who have not. (See Fein and Landman, 2005 for a history of Berkson's fallacy and examples in biomedical and psychiatric research.) In addition to alcoholism severity, findings on any measures of the antecedents or consequences of alcohol dependence that may be associated with levels of alcohol use (e.g., preexisting comorbid psychopathologic characteristics or exacerbation of comorbid psychopathologic characteristics) also may not extend from treated samples of alcoholics to untreated alcoholics in the general population.

Efforts to classify alcoholics into clinically meaningful subtypes began as far back as the nineteenth century (Babor et al., 1992, Babor and Lauerman, 1986, Meyer et al., 1983). Between then and now, there have been many attempts to derive a system of classification of alcoholics (Babor et al., 1992, Jellinek, 1960). As our understanding of the disease of alcoholism improved, typologies were discarded or expanded and refined (Babor et al., 1992, Hesselbrock et al., 1984, Morey et al., 1984, Moss et al., 2007, Penick et al., 1999, Schuckit, 1985, Sigvardsson et al., 1996). Penick et al., in a 1999 comparison of 11 typologies of alcohol-dependent individuals, concluded that the most powerful way of classifying alcoholics would require simultaneous consideration of at least two general dimensions: alcoholism severity and psychiatric comorbidity. A review of the literature shows that externalizing psychiatric disorders, chiefly antisocial personality disorder (ASPD), are considered by most to be the central psychiatric diagnoses in the classification of alcoholics, especially in severe alcoholism (although anxiety and mood disorders also play a role) (Cook et al., 1994, Epstein et al., 2002, Grant et al., 2004a, Grant et al., 2004c, Hauser and Rybakowski, 1997, Hesselbrock and Hesselbrock, 2006, Kessler et al., 1997, Moss et al., 2007, Penick et al., 1999, Sigvardsson et al., 1996, Windle and Scheidt, 2004).

In 2007, Moss et al., using data from the National Epidemiological Survey on Alcohol and Related Conditions (NESARC) reported that co-occurring psychiatric problems were associated with severity of alcoholism and entering into treatment, and that ‘help-seeking’ (i.e., treatment) remains relatively rare. They also concluded that the NESARC data suggest that a majority of people with alcoholism were not represented in the samples previously used to define alcoholism subtypes (Berkson's fallacy). Moss and colleagues went on to suggest a typology of five subtypes of (both treated and untreated) alcoholics. The discriminating features were ASPD, age of onset of alcohol dependence (AD), multigenerational familial AD, endorsement of specific alcohol dependence criteria, comorbid substance use disorders, comorbid mood and/or anxiety disorders, and consumption patterns as the most probable identifiers of subgroups of alcoholics. These conclusions are, of course, limited by the types of data collected by the NESARC (i.e., for psychiatric data, only disorders that reached criteria for diagnosis).

In 2007, we reported on the prevalence of psychiatric disorders (Di Sclafani et al., 2007) and measures of subdiagnostic psychiatric illness (Fein et al., 2007) (measures of the psychological substrate of psychiatric disorders and psychiatric symptom counts, whether or not they met criteria for a diagnosis) in the mood, anxiety and externalizing disorder domains in a sample of (primarily treated) long-term abstinent alcoholics compared to age- and gender-comparable controls. When we examined the psychiatric and psychological data, we found that long-term abstinent alcoholics had a much higher prevalence of psychiatric disorders than their non-alcoholic controls in all domains, but that the bulk of the difference between groups in psychiatric illness was subdiagnostic. In fact, even after removing individuals with (lifetime or current) diagnoses within each domain, there were still substantial differences between the groups on psychological measures and lifetime symptom counts, suggesting that examining diagnoses alone does not control for comorbid psychiatric problems in studies of alcoholism.

Since psychiatric problems are so often a major concomitant of alcohol dependence, and untreated alcoholics are so rarely examined in alcoholism research, the current study examined: (1) whether treatment-naive alcoholics are different from non-alcoholic controls in diagnostic and subdiagnostic comorbid psychiatric problems and, (2) if this difference exists, is it different in magnitude or type from the diagnostic and subdiagnostic psychiatric comorbidity exhibited by treated long-term abstinent alcoholics.