Causal attributions in clinical subtypes of depression: A longitudinal study of inpatients

Download Causal attributions in clinical subtypes of depression: A longitudinal study of inpatients

Post on 10-Jul-2016




1 download

Embed Size (px)


<ul><li><p>Journal of Psychopathology and Behavioral Assessment, 1/ol. 13, No. 3, 1991 </p><p>Causal Attributions in Clinical Subtypes of Depression: A Longitudinal Study of Inpatients </p><p>Asle Hoffart 1,2 and Egil W. Martinsen 1 Accepted: September 17, 1991 </p><p>The study material comprised inpatients who met DSM-III-R criteria for (a) dysthymia without panic and~or agoraphobia (n = 20), (b) major depression without panic and~or agoraphobia (n = 26), (c) both major depression and panic with agoraphobia (comorbid patients) (n = 17), and (d) panic with agoraphobia without any depressive disorder (n = 22). The patients completed the Attributional Style Questionnaire and the Beck Depression Inventory and were assessed on the Comprehensive Psychopathological Rating Scale upon admission to the hospital and at discharge. Some of the self-report scales were also administered at 1-year follow-up. It was assumed that dysthymic patients and patients with both major depression and agoraphobia wouM exhibit more biased attributions for bad events than "purely" major depressed and "purely" agoraphobic patients. However, inconsistent with this hypothesis, obtained group differences could be statistically reduced to differences in depressive symptom level At each assessment, attributions for bad events correlated significantly with depressive symptom level Attributional bias tended to decrease during treatment. However, most attribution subscales exhibited moderate stability in terms of correlation across assessments. Attributing bad events to global causes proved to predict later depression. KEY WORDS: attributions; depressive subtypes; longitudinal. </p><p>This research was supported by grants from the Halldis and Josef Andresen Legacy. 1Research Institute, Modum Bads Nervesanatorium, N-3370 Vikersund, Norway. 2To whom correspondence should be addressed. </p><p>241 </p></li><li><p>242 lloffart and Martinsen </p><p>INTRODUCTION </p><p>We all have a tendency to attribute causes to events that are impor- tant to us. In the hopelessness theory of depression, Abramson, Alloy, and Metalsky (1989) postulated that the habit of attributing bad events to stable and global causes and assigning importance to these events represents a vulnerability factor for the occurrence of depression. Thus, this model hy- pothesizes that attributions predict later depression. Earlier studies also in- dicated that this is the case (Brewin, 1985). However, no studies have investigated the unique predictive power of each of the relevant attribu- tional dimensions. The hopelessness model implies that the stability, global- ity, and importance dimensions all contribute independently to later depression. </p><p>Further, the hopelessness model presupposes that causal attributions express rather enduring personality traits. Another view is that cognitive biases are correlates or consequences of the depressive state itself. Whereas the hopelessness model predicts that attributional biases will persist beyond the remission of a depressive episode, the latter view implies that the biases will dissipate when symptoms remit. The evidence pertaining to this ques- tion is inconclusive. Hamilton and Abramson (1983) obtained differences in attributions for hypothetical events on the Attributional Style Question- naire (ASQ; Peterson et aL, 1982) between depressed and nondepressed patients. Upon remission, however, these differences disappeared. Con- trasting with these results, Eaves and Rush (1984) reported "depressogenic" attributions in depressed patients that were different from the control group and that persisted after the major symptom had disappeared. A pos- sible explanation of these divergent findings is that both the hopelessness model and the symptom perspective are partially valid. Abramson et al. (1989) suggested that the state of depression may strengthen already ex- isting traitlike cognitive biases. If this is true, attributional biases should decline with remission, but the rank order between individuals on the at- tributional dimensions should be fairly stable from a symptomatic to a re- mitted state. </p><p>The hopelessness model is supposed to explain only a specific type of depression (Abramson et aL, 1989). So far, however, this subtype has not been clearly identified. Hamilton and Abramson (1983) raised the pos- sibility that individuals suffering from chronic depressive syndromes, like dysthymia, may exhibit traitlike, depressogenic causal attributions. A stable tendency to think negatively should logically lead to some depressive symp- toms most of the time, as the individual would be expected to experience at least minor negative events regularly. Alloy, Kelly, Mineka, and Clements (1990) suggested that many hopelessness depressive patients may also be </p></li><li><p>Causal Attributions in Depressive Subtypes 243 </p><p>suffering from anxiety. This follows from the logic of the model: Hopeless- ness is a sufficient "proximal" cause of depression. Hopelessness includes both negative expectations about the occurrence of highly valued outcomes (a negative outcome expectancy) and feelings of helplessness about chang- ing the likelihood of occurrence of these outcomes. However, a sense of helplessness in controlling important future outcomes normally leads to anxiety. Individuals who suffer from depression that is based on hopeless- ness should therefore exhibit anxiety symptoms as well. Alloy et al. (1990) also suggest that several features of anxiety-depression comorbidity may be predicted from the hopelessness theory, for instance, that anxiety without depressive symptoms is more common than depression without anxiety symptoms. Recent cross-sectional studies have linked causal attributions to anxiety disorders and depression. Heimberg et al. (1989) found that dys- thymic patients did not differ from agoraphobic and social phobic patients regarding attributions. Hoffart and Martinsen (1990a) compared depressed and agoraphobic patients and failed to find the differences predicted from hopelessness theory. </p><p>The present longitudinal study examined causal attributions in dys- thymic patients, major depressed patients, patients with both agoraphobia and major depression, and nondepressed agoraphobic patients. The study represents an extension of the previous cross-sectional study (Hoffart &amp; Martinsen, 1990a), but the depressed patients were now divided into the mentioned diagnostic subtypes. Patients with agoraphobia and dysthymia were excluded from the group comparison part of this study because they were too few to form a group of their own. Furthermore, only patients who completed the repeated assessments were included. According to the rationales given above on possible "hopelessness" subtypes of depression, our first aim was to examine whether attributional biases were more promi- nent among dysthymic and comorbid patients. We therefore predicted the following. (1) Dysthymic and comorbid patients will attribute bad events to more stable and global causes, and assign more importance to these events, than patients with major depression or agoraphobia alone. These differences will persist over time and not be reducible to differences in depressive symptom level. To test the assumption that symptoms will pro- duce feedback on attributions, we set up two further predictions. (2a) After treatment, when depressive symptoms have presumably abated, the patients will display smaller biases on the bad events stability, globality, and impor- tance dimensions compared to themselves when they were acutely de- pressed. (2b) Bad events stability, globality, and importance scores will correlate with depressive symptom level. Finally, we wished to test the two presuppositions of the hopelessness model addressed above. (3) Attribution scores will exhibit stability over time in terms of correlations across assess- </p></li><li><p>244 Hoffart and Martinsen </p><p>ments. (4) Bad events stability, globality, and importance scores will con- tribute independently to later depression. </p><p>METHOD </p><p>Subjects </p><p>The sample consisted of inpatients at a Norwegian psychiatric insti- tution. The treatment program includes psychodynamically oriented psy- chotherapy, occupational and milieu therapy, physical exercise, and, in some cases, pharmacotherapy. A specialized exposure-based agoraphobia treatment program has been developed (Hoffart &amp; Martinsen, 1990b). Con- secutive patients were administered the SCID interview (Spitzer &amp; Wil- liams, 1984) for DSM-III-R Axis I and II diagnoses (American Psychiatric Association, 1987) shortly after admission. The group comparison part of this study covered patients who met the criteria for (a) dysthymia without panic and/or agoraphobia (n = 20), (b) major depression without panic and/or agoraphobia (n = 26), (c) both agoraphobia and major depression (comorbid patients; n = 17), and (d) agoraphobia without any depressive disorder (n = 22). Patients who met criteria for panic disorder and/or ago- raphobia were not further questioned about other anxiety disorders, and patients who met criteria for major depression were not asked about dys- thymia. Thus, some of the major depressed patients might have been dys- thymic as well. The second, predictive part of this study additionally included nine patients who met criteria both for panic disorder with agor- aphobia and dysthymia. The SCID interviews were conducted by one of the authors (E.W.M.). To assess the diagnostic reliability, 21 randomly se- lected audiotaped SCID interviews were independently scored by another psychiatrist. Interrater reliability was calculated by the use of kappa. The kappa value was .84 on Axis I and .76 on Axis II. Kappa values for indi- vidual Axis I diagnoses were .84 for dysthymia and agoraphobia and .90 for major depression. </p><p>Instruments and Procedure </p><p>Causal attributions were measured by the authors' Norwegian trans- lation of the ASQ. Here subjects were asked to imagine experiencing 12 events, 6 good and 6 bad, and to determine the possible major cause of each event. Next, they rated these causes on 7-point scales of internality, stability, and globality. The actual event was also rated for importance. In- </p></li><li><p>Causal Attributions in Depressive Subtypes 245 </p><p>ternal consistencies for good events were estimated, using Cronbach's alpha, to .67, .57, .61, and .56 for the internality, stability, globality, and importance subscales, respectively. For bad events, the corresponding val- ues were .69, .76, .62, and .71. On average, these alpha values were higher than those found in the original studies of the ASQ (Peterson et al., 1982). Factor analyses with varimax rotation of the ratings for internality, stability, globality, and importance on the 12 events supported a two-factor solution for all four dimensions, one for good and one for bad events. In each case, a scree test indicated two factors, and almost every item loaded (&gt;.40) exclusively on its expected factor. This is consistent with the original find- ings (Peterson et al., 1982). </p><p>The Beck Depression Inventory (BDI; Beck, Steer, &amp; Garbin, 1988) is a widely used and well-validated self-report instrument. The Compre- hensive Psychopathological Rating Scale (CPRS; Aasberg, Montgomery, Perris, Schalling, &amp; Sedvall, 1978) is composed of 65 0-30 scaled items covering a wide range of psychopathology. Symptoms are rated by an in- terviewer. In our study, we rated only the 38 items that were considered relevant for non-psychotic patients. In a former study of a larger sample (N = 146), which included the patients of the present study, we identified a 12-item index of depression (CPRS-D) and a 7-item index of anxiety (CPRS-A; Martinsen, Friis, &amp; Hoffart, 1989). The alpha values were .80 and .82 for the anxiety and depression indices, respectively. The indices differentiated well between patients with anxiety and those with depressive disorders among subgroups of anxiety and depression. Ratings on the CPRS were performed by either the first author or the mentioned psychia- trist. To assess interrater reliability, 20 randomly selected patients were in- terviewed and rated by the second author in the presence of the other two, who also rated these patients. The reliability was high for both indices, the intraclass correlations being .95 or above. </p><p>The patients completed questionnaires and were rated on the CPRS shortly after the diagnostic interview ("pretest") and at discharge ("post- test"). Follow-up investigation was performed one year after discharge by mailed questionnaires. Only the BDI and the internality scales of the ASQ were administered at follow-up. </p><p>Statistics </p><p>Pretherapy variables were tested for differences by F test for continu- ous variables and Z2 test for categorical variables. If the four-way group comparison revealed a difference significant at the .05 level, follow-up pair- wise comparisons were made using Duncan's test or 1-dr Z2 test. Repeated- </p></li><li><p>246 Hoffart and Mart insen </p><p>measures ANOVA was performed with Group as a between-subjects factor and Time as a within-subjects factor. Whenever this F test yielded a sig- nificant (p &lt; .05) group effect but no interaction, Duncan's post hoc test (p &lt; .05) was used. Whenever the repeated-measures ANOVA revealed a significant Group x Time interaction, we performed one-way ANOVAs at each assessment to detect the source of the interaction. Hierarchical re- gression was applied in the predictive analyses. </p><p>RESULTS </p><p>Group Comparisons </p><p>Demography, history of illness data, and treatment data for the 20 dysthymic, 26 major depressed, 17 comorbid (major depressed and agora- phobic), and 22 agoraphobic patients are presented in Table I. ANOVAs with Duncan's post hoc tests (p &lt; .05) indicated that the agoraphobic pa- tients were younger than the major depressed patients. ~2 test with 1-df Z 2 follow-up test indicated that more of the agoraphobic and comorbid than of the major depressed patients came from lower social classes (skilled or unskilled worker, unemployed, insured). Personality disorders were more frequent among comorbid than among major depressed patients. In addi- tion to "treatment as usual," many agoraphobic patients participated in the specialized exposure-based treatment program for agoraphobia. A greater number of the purely agoraphobic patients (19/22) than of the comorbid </p><p>Table I. Proportions/Means on Background and Treatment Variables for Diagnostic Groups a </p><p>Group </p><p>Variable D M MA A Test </p><p>Female 11/20 14/26 14/17 14/22 Z2 = 4.59 Lower social class 4/20 2/26 8/17 10/22 Z- = 12.73"* Age 41.3 45.4 41.8 36.9 F(3,81) = 3.05* Length of depressive episode (months) 50.2 25.2 43.6 - - F(2,59) = 1.87 Length of anxiety (years) - - - - 11.4 10.4 F2(1,38 ) = 0.45 Personality disorder 14/20 13/26 15/17 15/22 Z2 = 7.80* Exposure treatment - - - - 7/17 19/22 Z = 9.02* Using antidepressants 3/20 14/26 8/17 4/22 Z 2 = 10.84" Length of stay (weeks) 13.8 15.7 11.2 12.6 F(3,81) = 2.29 </p><p>aD, dysthymia; M, major depression; MA, major depression and phobia. </p><p>*p &lt; .05. **p &lt; .01. </p><p>agoraph...</p></li></ul>