Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Email this article to a Colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to My Articles & Searches Download to citation manager Citing Articles via Google Scholar Articles by Patten, S. B. Articles by Williams, J. V.A. Search for Related Content PubMed Citation Articles by Patten, S. B. Articles by Williams, J. V.A. Anxiety Disorders (General) Depression Syndromes Secondary to General Medical Disorders

Chronic Obstructive Lung Diseases and Prevalence of Mood, Anxiety, and Substance-Use Disorders in a Large Population Sample

Received March 8, 2006; revised June 30, 2006; accepted July 7, 2006. From the Department of Community Health Sciences, University of Calgary, Calgary, AB, Canada. Send correspondence and reprint requests to Scott B. Patten, M.D., Ph.D., 3330 Hospital Dr. NW, Calgary, AB, Canada T2N 4N1. e-mail: patten{at}ucalgary.ca
©2007 The Academy of Psychosomatic Medicine

ABSTRACT

TOP ABSTRACT INTRODUCTION METHOD RESULTS DISCUSSION REFERENCES

 
Only a few population-based studies have examined prevalence of mental disorder in people with chronic respiratory conditions. Clinical studies have yielded mixed results. In this analysis, data from the 2002 Canadian Community Health Survey (CCHS) were used. This was a national health survey that included administration of the World Mental Health Composite International Diagnostic Interview to a sample of 36,984 subjects. Participants were asked about chronic medical conditions that had been diagnosed by a health professional. Chronic respiratory conditions were associated with major depressive disorder, bipolar disorder, panic disorder (including agoraphobia), social phobia, and substance dependence. Although the observed associations were statistically highly significant, the prevalence estimates were lower than previous reports from studies using clinical samples, suggesting that selection bias may have influenced some estimates.

INTRODUCTION

TOP ABSTRACT INTRODUCTION METHOD RESULTS DISCUSSION REFERENCES

 
Despite numerous published studies of associations between mental disorders, asthma, chronic bronchitis, and emphysema, the quantity of epidemiological data describing these associations is limited. A review of the complex interactions between mental disorders and asthma was published by Lehrer et al.¹ A variety of mechanisms were identified by which 1) psychiatric conditions may contribute to the etiology, course, or clinical expression of these conditions; 2) by which asthma may contribute to the emergence of depression and anxiety; or 3) by which poor mental health status may affect the capacity of asthma sufferers to cope with their illness. In keeping with these ideas, two small, nonrandomized clinical trials have reported that mental health care can improve psychological symptoms associated with asthma.^2,3

Zandbergen et al.⁴ reviewed clinical records from a series of adult patients with anxiety disorders and found an elevated lifetime history of respiratory disorders (47%) in patients with panic disorder. Yellowlees et al.⁵ administered the Diagnostic Interview Schedule (DIS) to a clinical sample of asthmatic patients. The most common diagnosis identified was panic disorder, followed by phobic disorders and posttraumatic stress disorder; 2 of 49 patients evaluated had depressive disorders. Gedanke et al.⁶ used the DIS to identify psychiatric disorders in a clinical sample of 107 subjects with asthma; 13.1% of the subjects were found to have panic disorder, and 6.5% had agoraphobia.

Although many studies conducted in clinical settings have evaluated the mental health of patients with asthma, population-based studies are scarce. One study recruited volunteer subjects, primarily through newspaper advertisements, Carr et al.⁷ reported a very high prevalence of panic disorder: 9.7% of respondents met DSM–III-R criteria for panic disorder. Bias may be introduced as a result of reliance on clinical and volunteer subjects in studies such as these. Such subjects may differ in important ways from members of the general population. It seems reasonable to hypothesize that the direction of bias would be toward an elevated prevalence of mental disorders in clinical studies. Clinical subjects may have especially severe forms of respiratory disorder. It is also possible that the diminished level of functioning associated with mental disorders might lead to inefficient self-management or reduced medication compliance. Each of these mechanisms could lead to an increased frequency of mentally ill subjects in clinical settings.

The current literature includes a range of depression prevalence estimates in asthma, from 1% to 45%,⁸ a range so wide that it is of questionable use for public health or clinical applications. In addition to the possible role of selection bias, heterogeneous measurement strategies and diagnostic definitions may contribute to the wide range of estimates in this literature.

Whereas the asthma literature has tended to emphasize panic disorder and depression, the literature concerned with conditions characterized by irreversible airway obstruction (chronic obstructive pulmonary disease [COPD] and emphysema) are believed by some authors to be more strongly associated with depression than with anxiety.¹ Van Manen et al.⁹ reported that general-practice patients with COPD had elevated scores on the Center for Epidemiologic Studies Depression Rating Scale (CES–D) that persisted after adjustment for demographic variables. However, a case–control study by Isoaho et al.¹⁰ found no difference in depression ratings on the Zung scale. Yellowlees et al.¹¹ found a higher prevalence of anxiety disorders (34%) than depressive disorders (16%) in a hospitalized series of 50 patients who were assessed with unstructured psychiatric interviews. However, each of these studies used clinical subjects, and may therefore be subject to bias. A 1999 review by van Ede et al.¹² determined that the evidence linking COPD to depression was inconclusive. More recently, Kunik et al.¹³ reported a "surprisingly high" prevalence of mood and anxiety disorders in a sample of veterans with a mixed set of chronic breathing disorders. Approximately 80% of the sample screened positive for depression or anxiety when assessed with screening questions; 80% of these had high levels of depressive symptoms on symptom rating scales, and 65% of the latter group had a depressive or anxiety disorder according to a semistructured diagnostic interview. Porzelius et al.¹⁴ reported that 37% of a clinical sample with COPD reported having experienced a panic attack. Another clinical series was found to have a 16% prevalence of anxiety disorders, as identified by the Structured Clinical Interview for DSM–III-R (SCID).¹⁵ This study also found an 18% prevalence of mood disorders.

The literature concerned with psychiatric-disorder prevalence in people with chronic respiratory conditions is both limited and inconsistent. Some of the inconsistencies may result from inadequate measurement strategies (e.g., the use of symptom rating scales rather than diagnostic interviews), but another likely explanation is the reliance on clinical subjects. When prevalence is measured in clinical populations, it can be expected to represent characteristics of not only the illness, but of the healthcare settings and healthcare systems that shape these clinical populations. Developing a better understanding of the epidemiology of these purported associations should derive from studies using solid measures of psychiatric disorders, and these studies should use general population samples. The objective of this study is to describe the prevalence of mood, anxiety, and substance-use disorders in association with respiratory conditions in a large general-population sample.

METHOD

TOP ABSTRACT INTRODUCTION METHOD RESULTS DISCUSSION REFERENCES

 
The Canadian Community Health Survey, Mental Health and Well-Being (CCHS 1.2) was conducted in 2002. The CCHS 1.2 sample included 36,984 subjects randomly selected from the population of household residents in Canada, with the exception of some native groups, armed forces personnel, and residents of some remote areas. The subjects were interviewed in person whenever possible, at their homes, by trained and experienced interviewers using computer-assisted interview methods.¹⁶ Telephone interviews were permitted only when travel was prohibitive or the respondent refused to conduct the interview in person; 5,173 interviews were conducted over the telephone. The response rate was 77% nationally. The interview included the World Mental Health Composite International Diagnostic Interview (WMH–CIDI).¹⁷ This is a fully structured psychiatric diagnostic interview. The version of the WMH–CIDI used in the CCHS 1.2 produced diagnoses of major depressive disorder, bipolar disorder, panic disorder, agoraphobia, and social phobia. The WMH–CIDI interview also evaluated subjects for illicit drug dependence, and, in the CCHS 1.2, this was supplemented by an assessment of alcohol dependence that used the CIDI Short Form.¹⁸

CCHS 1.2 subjects were read a list of chronic medical conditions and asked whether they had been diagnosed with one of these conditions by a health professional. The exact wording of the item was "Now I’d like to ask about certain chronic health conditions which you may have. We are interested in long-term conditions that are expected to last or have already lasted 6 months or more and that have been diagnosed by a health professional." This was followed by "Do you have asthma?" A list of chronic conditions followed, and subjects were reminded of the requirement for a diagnosis by a health professional by means of this statement: "Remember, we’re interested in conditions diagnosed by a health professional. Do you have chronic bronchitis?" A third question asked about emphysema, but also included the phrase "chronic obstructive pulmonary disease:" "Do you have emphysema or chronic obstructive pulmonary disease (COPD)?"

The CCHS 1.2 used a complex sampling strategy that involved both stratification and clustering. These design features require the application of sampling weights and specialized variance-estimation procedures. Statistics Canada recommends a bootstrap procedure for variance-estimation. This procedure was used, along with sampling weights, in producing the estimates presented in this article. The analysis presented here consists of estimated frequencies, along with logistic-regression modeling, to produce estimates of association, adjusted for demographic variables.

RESULTS

TOP ABSTRACT INTRODUCTION METHOD RESULTS DISCUSSION REFERENCES

 
One or more respiratory illnesses were reported by 4,448 of the study subjects. The weighted prevalence of respiratory disease was 10.8% (95% confidence interval [CI]: 10.4–11.3). Among men, the prevalence was 9.2% (95% CI: 8.6–9.9), and among women it was 12.4% (95% CI: 11.7–13.0). The prevalence of respiratory disease did not differ to a large extent by age. In the 15–24 age-range, the prevalence was 12.8% (95% CI: 11.7–14.0); in the 25–44 age-range, it was 10.0% (95% CI: 9.2–10.7); in the 45–64 and 65+ age-ranges, the prevalence was 9.7% (95% CI: 8.9–10.5) and 13.2% (95% CI: 12.2–14.2), respectively.

Of the three respiratory conditions, the highest prevalence was for asthma, at 8.5% (95% CI: 8.1–9.0). The prevalence of asthma was slightly higher in the 15–44-year age-group, 9.4% (95% CI: 8.8–10.0) than in the 45+ age-group, at 7.4% (95% CI: 6.9–8.0). The overall prevalence of chronic bronchitis was 3.3% (95% CI: 3.0–3.5). The prevalence of chronic bronchitis was slightly higher in women than in men (3.9% versus 2.6%), and the prevalence peaked in the 65+ age-group, at 6.1% (95% CI: 5.4–6.9). The prevalence of emphysema was 1.0% (keeping in mind that the questionnaire item also mentioned COPD), with a 95% CI: of 0.9–1.1. Again, the peak prevalence was observed in the 65+ age-group, at 3.7% (95% CI: 1.8–2.4). Those having a single condition were 9.1% of the population (95% CI: 8.7–9.5), and those having more than one of these conditions were 1.7% (95% CI: 1.6–1.9).

Prevalence of psychiatric disorder was generally higher in subjects with respiratory disease than in subjects with no respiratory disease or subjects reporting no chronic conditions (see Table 1). Crude (unadjusted) odds ratios (ORs) for each of the psychiatric disorders in subjects with individual conditions were generally elevated, but some of these estimates were associated with very wide confidence intervals. Adjusted ORs are presented in Table 2. These derive from logistic-regression models that included age and sex in addition to indicator variables for the specific respiratory conditions.

View this table: [in this window] [in a new window]

TABLE 1. Prevalence of Psychiatric Disorder in Subjects With and Without Respiratory Conditions, Percent (Range: 95% Confidence Interval)

View this table: [in this window] [in a new window]

TABLE 2. Adjusted Odds Ratios, With 95% Confidence Intervals, for Psychiatric Disorders, Grouped by Respiratory Condition

In the analysis of individual conditions, some models contained interaction terms that precluded the reporting of a single effect for the respiratory condition. To assist with interpretation of the interactions observed, Figure 1 presents fitted values for the model predicting major-depression prevalence in subjects with asthma. The prevalence of major depression declines with age in men and women who do not have asthma, but the difference between men and women becomes smaller with advancing age (this is represented in the model by an age x sex interaction). The prevalence in subjects with asthma is higher than those without asthma at any given age, but the decline in prevalence with age is not as evident in the subjects with asthma, such that the age-specific effect of asthma becomes stronger with advancing age (this effect is represented in the model by an age x asthma interaction).

View larger version (64K): [in this window] [in a new window]

FIGURE 1.  Adjusted Prevalencea of Major Depression, by Asthma Status, Age, and Sex a The fitted proportions from this logistic-regression model: 1n (odds Major Depression) = –3.24284 + 0.15908 * Asthma – 0.00751 * Age + 1.10094 * Female sex – 0.01372 * Age * Female sex + 0.01056 * Asthma * Age.

The remaining analyses focused on a combined group of subjects having one or more of the respiratory conditions. The estimates of effect are the ORs in the far right column of Table 2. All of these estimates are adjusted for age and sex, and some of the models required the retention of age x sex interaction terms. However, there were no interactions involving the respiratory conditions. Prevalence estimates for psychiatric disorders, stratified by age and sex, in subjects with respiratory disorders, are presented in Table 3. Prevalence was seen to decrease with age for all disorders; mood and anxiety disorders were more common in women; and substance-dependence was more common in men. These estimates complement the adjusted ORs from Table 2 by providing information about the frequency of the various psychiatric disorders.

View this table: [in this window] [in a new window]

TABLE 3. Prevalence of Psychiatric Disorder in Subjects with Respiratory Disease, by Age and Sex; Percent (95% Confidence Interval)

DISCUSSION

TOP ABSTRACT INTRODUCTION METHOD RESULTS DISCUSSION REFERENCES

 
A previously reported elevation in major-depression prevalence in subjects with respiratory conditions was confirmed by this analysis. An association between respiratory conditions and panic disorders has received emphasis in the literature; however, the results presented here indicate that the association between respiratory disorders and anxiety are not specific for panic disorder. An increased prevalence of social phobia was also found. An elevated prevalence of substance-use disorder was also observed, which, to our knowledge, has not previously been reported.

In DSM–IV, disturbances of mood and anxiety that are judged to be due to the direct physiological consequences of a general-medical condition are placed in different categories: "mood and anxiety disorders due to a general-medical condition."¹⁹ Etiological distinctions of this sort cannot be made from cross-sectional epidemiological data. However, the estimates presented here are important in several ways. First, they confirm that psychiatric disorders occur with an increased frequency in association with respiratory conditions. Second, they illustrate that the associations extend beyond the most widely studied conditions: major depression and panic disorder. Third, they indicate that the prevalence of psychiatric disorders in people with respiratory conditions in the community are lower than those previously reported in clinical samples.

Smoking has been reported to be an effect-modifier of the association between distress and depressed mood and depressive and anxious symptoms in workers with respiratory diseases.²⁰ Smoking was not measured in the CCHS, so it was not possible to include this variable in the analysis. However, it should be emphasized that the main goal of this article was to describe the strength of these associations in a population sample, rather than to develop an etiological model. Cross-sectional data are generally not well suited for etiological analyses. An additional limitation is the reliance on self-reported respiratory-disease status. However, the relevant items did refer to physicians’ diagnoses, an approach that may be insensitive, but is likely to be highly specific for these conditions.²¹

Previously reported associations between depression, anxiety, and respiratory conditions were not merely artifacts of measurement error (i.e., the use of symptoms rather than diagnoses) nor of selection bias. However, the strength of the association may have been exaggerated as a result of selection bias in previous studies. It does appear that previous clinical studies have tended to report higher prevalence estimates than exist in the general population. These associations occur across a broad range of psychopathology, including substance-dependence.

ACKNOWLEDGMENTS

 
This analysis used data collected by Statistics Canada, but the results and conclusions do not reflect the views of Statistics Canada.

The study was supported by a grant from the Research Coordinating Committee of the Institute of Health Economics.

REFERENCES

TOP ABSTRACT INTRODUCTION METHOD RESULTS DISCUSSION REFERENCES

 

1. Lehrer P, Feldman J, Giardino N, et al: Psychological aspects of asthma. J Consult Clin Psychol 2002; 70:691–711[CrossRef][Medline]
2. Grover N, Kumaraiah V, Prasadrao PSDV, et al: Cognitive behavior intervention in bronchial asthma. J Assoc Physicians India 2002; 50:896–900[Medline]
3. Maes S, Schlösser M: Changing health behavior outcomes in asthmatic patients: a pilot intervention study. Soc Sci Med 1988; 26:359–364[CrossRef][Medline]
4. Zandbergen J, Bright M, Pols H, et al: Higher lifetime prevalence of respiratory diseases in panic disorder. Am J Psychiatry 1991; 148:1583–155[Abstract/Free Full Text]
5. Yellowlees PM, Haynes S, Potts N, et al: Psychiatric morbidity in patients with life-threatening asthma: initial report of a controlled study. Med J Aust 1988; 149:246–249[Medline]
6. Gedanke R, Gentil V, Mandetta R: The association of panic/agoraphobia and asthma. contributing factors and clinical implications. Gen Hosp Psychiatry 1992; 14:420–423[CrossRef][Medline]
7. Carr RE, Lehrer PM, Rausch LL, et al: Anxiety sensitivity and panic attacks in an asthmatic population. Behav Res Ther 1994; 32:411–418[CrossRef][Medline]
8. Opolski M, Wilson I: Asthma and depression: a pragmatic review of the literature and recommendations for future research. Clin Psychol Sci Pract 2005; 1:18
9. van Manen JG, Bindels PJE, Dekker FW, et al: Risk of depression in patients with chronic obstructive pulmonary disease and its determinants. Thorax 2002; 57:412–416[Abstract/Free Full Text]
10. Isoaho R, Keistinen T, Laippala P, et al: Chronic obstructive pulmonary disease and symptoms related to depression in elderly persons. Psychol Rep 1995; 76:287–297[Medline]
11. Yellowlees PM, Alpers JH, Bowden JJ, et al: Psychiatric morbidity in patients with chronic airflow obstruction. Med J Aust 1987; 146:305–307[Medline]
12. van Ede L, Yzermans CJ, Brouwer HJ: Prevalence of depression in patients with chronic obstructive pulmonary disease: a systematic review. Thorax 1999; 54:688–692[Abstract/Free Full Text]
13. Kunik ME, Roundy K, Veazey C, et al: Surprisingly high prevalence of anxiety and depression in chronic breathing disorders. Chest 2005; 127:1205–1211[CrossRef][Medline]
14. Porzelius J, Vest M, Nochomovitz M: Respiratory function, cognitions, and panic in chronic obstructive pulmonary patients. Behav Res Ther 1991; 30:75–77[CrossRef]
15. Karajgi B, Rifkin A, Doddi S, et al: The prevalence of anxiety disorders in patients with chronic obstructive pulmonary disease. Am J Psychiatry 1990; 147:200–201[Abstract/Free Full Text]
16. Gravel R, Béland Y: The Canadian Community Health Survey: Mental Health and Well-Being. Can J Psychiatry 2005; 50:573–579[Medline]
17. Kessler RC, Ustun TB: The World Mental Health (WMH) Survey Initiative Version of the World Health Organization (WHO) Composite International Diagnostic Interview (CIDI). Int J Meth Psychiatr Res 2004; 13:83–121
18. Kessler RC, Andrews G, Mroczek D, et al: The World Health Organization Composite International Diagnostic Interview-Short Form (CIDI-SF). Int J Meth Psychiatr Res 1998; 7:171–185[CrossRef]
19. American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision. Washington, DC, American Psychiatric Association, 2000
20. Wagena EJ, Kant IJ, Huibers MJH, et al: Psychological distress and depressed mood in employees with asthma, chronic bronchitis, or emphysema: a population-based observational study on prevalence and the relationship with smoking cigarettes. Eur J Epidemiol 2004; 19:147–153[CrossRef][Medline]
21. Toren K, Brisman J, Jarvholm B: Asthma and asthma-like symptoms in adults assessed by questionnaires: a literature review. Chest 1993; 104:600–608[CrossRef][Medline]

Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Email this article to a Colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to My Articles & Searches Download to citation manager Citing Articles via Google Scholar Articles by Patten, S. B. Articles by Williams, J. V.A. Search for Related Content PubMed Citation Articles by Patten, S. B. Articles by Williams, J. V.A. Anxiety Disorders (General) Depression Syndromes Secondary to General Medical Disorders

Get information about faster international access.

Privacy Policy

Copyright © 2007 Academy of Psychosomatic Medicine. All rights reserved.

Home | Search | Current Issue | Past Issues | Subscribe | All APPI Journals | Help | Contact Us