Construct Accessibility and Clinical Depression - American ...

Journal of Abnormal Psychology 1987, Vol. 96, No. 3,199-204

Copyright 1987 by the American Psychological Association, Inc. 0021-843X/87/S00.75

Construct Accessibility and Clinical Depression: A Longitudinal Investigation Ian H. Gotlib and Douglas B. Cane

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University of Western Ontario London, Ontario, Canada

There is a rapidly growing body of literature that examines the role of cognitive processes in the etiology and maintenance of depression. In general, empirical support for the causal aspects of cognitive models of depression has been mixed. This study was designed to examine construct accessibility in depressed patients both during and following their hospitalization. Depressed psychiatric patients and nondepressed controls participated twice in a modified Stroop task, naming the colors of tachistoscopically presented depressed-, neutral-, and manic-content words. In addition, a cognitive priming procedure designed to temporarily alter the differential accessibility of the subjects to the three categories of words was assessed. As predicted, the depressed patients took longer to name the colors of the depressed-content than the nondepressed-content words. This effect, however, was obtained only for the hospitalization session, when the patients were clinically depressed; no significant group differences were obtained for the discharge session, when the patients had improved symptomatically. These results suggest that patterns of cognitive functioning hypothesized by cognitive theorists to be implicated in the etiology of depression vary with recovery from depression. Finally, there was no evidence that priming effectively alters either the negative construct accessibility or the affective state of depressed patients.

There is a rapidly growing body of literature that examines the relation between depression and cognitive functioning. A number of these studies are based largely on Beck's (1967, 1976) cognitive model of depression. Briefly, Beck's model ascribes central importance to the concept of "schemata," cognitive structures that affect the encoding, storage, and retrieval of information. Beck postulated that the schemata used by depressed people are essentially negative, leading the depressive selectively to filter out positive information and exaggerate negative information. Consequently, depressed people often inaccurately perceive their environment. More important, this model ascribes a causal role to these cognitive processes in predisposing a person to depression. Thus people who possess certain identifiable cognitive characteristics (e.g., negative schemata) are assumed to be at increased risk for developing depression. Empirical support for this model of depression has been mixed. Although some studies have found that depressed subjects perceive and recall feedback to be more negative than is actually the case (e.g., Buchwald, 1977; Gotlib, 1981, 1983), others have reported findings suggesting that depressed subjects are accurate in their perceptions and that nondepressed subjects distort in a positive direction (e.g., Alloy & Abramson, 1979;

Lewinsohn, Mischel, Chaplin, & Barton, 1980; Nelson & Craighead, 1977). Studies specifically investigating the etiological role of cognitions in depression have yielded similarly equivocal results. Eaves and Rush (1984), for example, found that remitted depressives differ from nondepressed controls with respect to the number of dysfunctional attitudes endorsed, and several longitudinal studies have been able to predict the occurrence, intensity, and variability of subsequent depression from prior levels of hopelessness and irrational beliefs (e.g., Rholes, Riskind, & Neville, 1985; Vestre, 1984). In contrast to these findings, however, several studies have found that cognitive variables hypothesized to play an etiological role in depression seem instead to vary over time in a linear fashion with changes in depressive symptomatology (e.g., E. W. Hamilton & Abramson, 1983; Reda, Carpiniello, Secchiarole, & Blanco, 1985; Silverman, Silverman, & Eardley, 1984). Furthermore, researchers have found cognitive changes to accompany changes in level of depression even when treatment interventions were not aimed directly at modifying these patients' dysfunctional beliefs (Simons, Garfield, & Murphy, 1984). Finally, both Lewinsohn, Steinmetz, Larsen, and Franklin (1981) and Persons and Rao (1985) were unable to predict subsequent depression using a wide variety of cognitive measures (see Coyne & Gotlib, 1983, 1986, for a more detailed evaluation of these studies). One difficulty shared by all of these investigations is that they rely in large part on self-report measures of cognitive functioning. Interestingly, studies examining more molecular aspects of information processing have also provided evidence suggesting that cognitive changes accompany changes in level of depression. Both induced and naturally occurring depressed mood have been found to be associated with quicker recall of unpleasant than pleasant memories (e.g., Clark & Teasdale, 1982; Lloyd &Lishman, 1975; Teasdale &Fogarty, 1979)andtofacil-

Completion of this study was facilitated by Grant A0575 from the Natural Sciences and Engineering Research Council of Canada and by Grant MA-8574 from the Medical Research Council of Canada to Ian H. Gotlib. We express our appreciation to Deanne Day for her assistance in collecting the data reported in this study. Correspondence concerning this article should be addressed to Ian H. Gotlib, Department of Psychology, University of Western Ontario, London, Ontario, Canada N6A 5C2.

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itate the processing of unfavorable feedback (e.g., Gotlib, 1983; Ingram, 1984). In sum, mood appears to influence the accessibility of stimuli containing mood-congruent information (for a more detailed review of studies in this area, see Blaney, 1986), and the results of these studies, particularly the mood induction studies, suggest that negative cognitions may be more parsimoniously viewed as symptoms of, rather than etiological factors in, depression. In an alternative test of the mood-accessibility formulation, Gotlib and McCann (1984) used a modified version of the Stroop (1935) Color-Word Interference Test to examine cognitive accessibility differences between depressed and nondepressed people. The Stroop procedure requires subjects to name the color of ink in which color and noncolor words are presented. It is a well-established finding that subjects demonstrate longer response times to naming the ink colors of different-color words (e.g., green printed in blue ink) than they do to naming the ink colors of noncolor words (e.g., sock printed in blue ink). Investigators have interpreted this difference in terms of response interference—the automatic processing of the content of the color word interferes with the competing response of naming the (different) ink color, resulting in an increased latency for naming the ink color of color relative to noncolor words. Gotlib and McCann (1984) reasoned that if, as Beck posits, depressed people are characterized by negative schemata through which they automatically filter environmental information, these schemata should increase the depressives' accessibility and attention to the content of negative-content words, thereby interfering with their ability to name quickly the colors in which these negative-content words are printed. To test this hypothesis, Gotlib and McCann had mildly depressed and nondepressed students participate in a variation of the Stroop task in which they were required to name the colors of 150 depressed-, neutral-, and manic-content words. As predicted, the depressed subjects demonstrated longer response latencies to the depressed-content than to either the neutral- or the maniccontent words; the nondepressed subjects did not demonstrate differential response latencies to the three types of words. Although this is an intriguing finding, a number of issues remain unresolved. First, Gotlib and McCann (1984) assessed construct accessibility in mildly depressed, or dysphoric (cf. Gotlib, 1984), university students, and the generalizability of the results to clinical depression is not clear. One purpose of the present study, therefore, was to extend these findings to a clinically depressed population. Second, because Gotlib and McCann tested subjects only once, the stability of these accessibility differences and their relation over time with depression was not assessed. A second purpose of the present study was to address this issue. Depressed psychiatric inpatients and nondepressed nonpsychiatric controls participated in the modified Stroop task at two times: first, while the patients were hospitalized and clinically depressed, and second, within a week following their discharge, at which time they were no longer clinically depressed. The nondepressed controls were time matched to the patients. The collection of longitudinal data allows for a more stringent test of competing hypotheses concerning the relation over time of cognitive accessibility and depression. If, as cognitive theorists postulate, accessibility differences are relatively stable and persist beyond the limits of a depressive episode, a

significant two-way interaction (Group X Word Type) should be obtained, with depressed patients demonstrating interference for the negative words in both the hospital and the discharge sessions. On the other hand, if accessibility differences are a concomitant of depression, a significant three-way interaction (Group X Word Type X Session) should be obtained, in which the depressed subjects should demonstrate interference for the negative words in Session 1, when they are clinically depressed, but not in Session 2, following their recovery. Finally, in the Gotlib and McCann study, no attempt was made to alter experimentally the increased negative accessibility of the depressed subjects, and it is not clear whether a procedure designed to achieve this effect would be successful. To address this issue, we included a cognitive priming procedure in this study in an attempt to temporarily modify the differential accessibility of the subjects to the three types of words.

Method Subjects Thirty-four depressed psychiatric inpatients and 14 nondepressed nonpsychiatric controls served as subjects in this study. To be included in the study, patients needed to (a) have a current hospitalization of between 3 and 35 days, (b) be between 18 and 60 years of age, (c) have at least an eighth-grade education, and (d) show no evidence of brain damage, alcoholism, drug addiction, or psychotic ideation. Diagnoses of depression were based on Diagnostic and Statistical Manual of Mental Disorders (DSM-HI; American Psychiatric Association, 1980) criteria. In addition, to facilitate comparisons with previous studies, all subjects completed the short form of the Beck Depression Inventory (BDI-SF; Beck & Beck, 1972) prior to Session 1. The Hamilton Rating Scale for Depression (HRSD; M. Hamilton, 1960) was also administered to the depressed patients prior to the first session. The BDI-SF is a 13-item self-report measure of the depth or severity of depression. The total score represents a combination of the number of symptom categories endorsed and the severity of the particular symptoms. Previous studies have demonstrated that this measure correlates highly with the longer form of the BDI as well as with clinicians' ratings of depression (Beck, Rial, & Rickels, 1974; Reynolds & Gould, 1981). The HRSD is a 17-item clinician-rated inventory scored on the basis of a structured interview with the patient. By summing the ratings obtained for each item, a total score is derived that represents a global rating of the severity of the depression. The HRSD has shown acceptable levels of both validity (Carroll, Fielding, & Blashki, 1973) and interrater reliability (Bech et al., 1975). Patients were classified as depressed if they obtained a DSM-III diagnosis of major depressive episode or dysthymic disorder. Nondepressed nonpsychiatric controls were solicited through a community newspaper advertisement requesting participants in a study of reaction time. To be included in this group, individuals had to be between 18 and 60 years of age, have a BDI-SF score of 5 or less, and have no reported major current or past problems with depression. The nondepressed controls were selected to match the depressed patients with respect to age. After permission was obtained from their therapists, patients were approached by a research assistant who requested their participation in a study examining reaction times to various stimuli. Nondepressed controls were screened over the telephone (with the exception of completing the BDI-SF, which was done at the beginning of the first session). Before they participated in the study proper, patients were seen in individual sessions in which they completed the BDI-SF and were interviewed and assessed on the DSM-III criteria and the HRSD by a clinical

CONSTRUCT ACCESSIBILITY AND CLINICAL DEPRESSION psychologist or a doctoral student in clinical psychology.1 Patients were allowed to participate in the study if they met the DSM-HI criteria outlined earlier. The first session for each patient took place within one week of the assessment session, and the second session took place within one week following discharge from the hospital. The second sessions for the nondepressed control subjects were time matched to those of the patients. All subjects were paid $10 to participate in each of the two sessions.

second half of the original task, naming the color of each of the remaining 75 stimulus words. After the presentation of all 150 stimulus words, subjects completed the Depression scale of the Multiple Affect Adjective Check List (MAACL-D; Zuckerman & Lubin, 1965) in order to provide a measure of immediate mood. Finally, the experimenter thanked subjects for their participation and made arrangements for them to return for the second session.


Materials and Equipment The 150 words used by Gotlib and McCann (1984) served as stimuli in the present study. Fifty of the words were adjectives that an independent sample of depressed patients had rated as highly self-descriptive and manic patients had rated as not self-descriptive (depressed-content words). Similarly, 50 of the words were adjectives that manic patients had rated as self-descriptive and depressed patients had rated as not selfdescriptive. These manic-content words were included both to determine whether differential response latencies to the depressed-content words might be a function of the affective nature of the words rather than the depressed content per se, and to assess the effects of a positive priming procedure on responses to positive words. The final 50 words (neutral content) were selected from Thorndike and Lorge's (1944) list and were matched with the depressed- and manic-content words with respect to frequency of occurrence (see Gotlib & McCann, 1984, for a more detailed description of the procedure used to select the words). The words were printed in capital letters, 5/i6 in. (8mm) high, on 4 X 6 in. (10.2 X 15.3 cm) white index cards. Each word was printed in red, blue, yellow, green, or brown ink, with 10 words in each of the three categories printed in each color.

Procedure The procedure was identical for both sessions. Each subject was tested individually. An experimenter told subjects that they would be asked to name aloud the colors of a series of words. The words were presented in random order for each subject via a two-field tachistoscope. A microphone was positioned approximately 2% in. (7 cm) from the subject's mouth. The microphone was connected to a voice-activated relay that stopped a timer at the initiation of the subject's vocal response. Subjects were told that five colors would be used and were given five practice trials, naming the colors of the words one, two, three, four, and five. When it was clear that each subject understood the task requirements, the experimenter presented half of the 150 stimulus words, 25 from each of the three categories. Each trial consisted of a 1-s presentation of a fixation cross, followed by a 250-ms blank interval, followed by the presentation of a stimulus word. Onset of the stimulus started the timer, and the subject's vocal response stopped it. Each stimulus remained in view for 1.5 s, regardless of the subject's reaction time. The interval between stimulus presentations (approximately 5 s) was used by the experimenter to record the response latency and to reset the equipment for the next trial. When the 75 words had been presented, the subject was exposed to a procedure, similar to that developed by Higgins, Rholes, and Jones (1977), designed to prime (or increase the accessibility of) either positive or negative categories. This procedure, presented as a memory task, required the subject to listen to each of 15 positive or negative priming words. The two sets of words were selected from the positive and negative ends of Osgood's semantic differential. The positive priming words included beauty, excellent, and love, whereas the negative priming words included bad, disease, and hate. None of the priming words was also used as a stimulus word. For each priming word, the subject was required to listen to the word and repeat it immediately, then to view and name the color of a square presented on the tachistoscope, and finally, to again repeat the priming word. This procedure was repeated for all 15 words. Following this priming procedure, the subject completed the

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Results Group Characteristics Of the 34 depressed patients, 27 received a diagnosis of major depressive episode, and 7 received a diagnosis of dysthmic disorder. Mean ages were 33.7 (SD = 9.3) for the depressed patients and 30.8 (SD = 11.1) for the nondepressed subjects, f(46) < 1. The depressed group contained 10 men and 24 women, and the nondepressed group contained 6 men and 8 women, \2(l,N = 48)