Self-Discrepancy in Chronic Low Back Pain: Relation to Pain, Depression, and Psychological Distress

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1 Vol. 27 No. 3 March 2004 Journal of Pain and Symptom Management 251 Original Article Self-Discrepancy in Chronic Low Back Pain: Relation to Pain, Depression, and Psychological Distress Sandra J. Waters, PhD, Francis J. Keefe, PhD, and Timothy J. Strauman, PhD Pain Prevention and Treatment Program (S.J.W., F.J.K.), Duke University Medical Center; and Department of Psychology: Social and Health Sciences (T.J.S.), Duke University, Durham, North Carolina, USA Abstract Self-discrepancies occur when patients evaluations of their actual self differ from their views of who they ideally would like to be (ideal self) or feel they ought to be (ought self), or from patients perceptions of how significant others wish they could be (ideal-other self) or ought to be (ought-other self). These self-discrepancies may be related to psychological functioning and adjustment to pain. This study sought to: 1) determine the reliability of self-discrepancy assessments in patients; 2) determine whether each of the four types of selfdiscrepancies (actual self vs. ideal self, actual self vs. ought self, actual self vs. ideal-other self and actual self vs. ought-other self) measure a distinct type of self-discrepancy; and, 3) examine the relationship of self-discrepancies to pain intensity, depression, and psychological distress in 93 chronic low back pain patients. A semi-structured questionnaire assessed self-discrepancies. Standardized measures were used to assess pain intensity, depression, and psychological distress. Results showed that self-discrepancies can be reliably assessed in patients with persistent pain. Furthermore, data analyses showed that patients who had large ought-other self-discrepancies reported more severe pain and higher levels of psychological distress. Patients who had large ideal self-discrepancies reported higher levels of depression and psychological distress. Taken together, these findings suggest that selfdiscrepancy can be reliably assessed in patients with persistent pain and demonstrate that self-discrepancies are related in meaningful ways to measures of pain, depression, and psychological distress in chronic low back pain patients. J Pain Symptom Manage 2004;27: U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved. Key Words Self-discrepancy, chronic low back pain, pain severity, depression, psychological distress Address reprint requests to: Sandra J. Waters, PhD, Pain Prevention and Treatment Research, Duke University Medical Center, DUMC 3159, Durham, NC 27710, USA. Accepted for publication: July 21, U.S. Cancer Pain Relief Committee Published by Elsevier Inc. All rights reserved. Introduction Persistent pain is one of the most challenging stressors that a person can face. Persons suffering from prolonged pain frequently report that living with pain alters their views of themselves. In specialized pain treatment settings, in /04/$ see front matter doi: /j.jpainsymman

2 252 Waters et al. Vol. 27 No. 3 March 2004 particular, patients often state that, because of changes brought on by pain, they are no longer able to live up to their own views of how they would like to be or how they feel they ought to be. There is growing recognition that a discrepancy between how one is and how one would like to be plays a role in the experience of painrelated suffering. 1 Self-discrepancy theory 2 provides a theoretical model that may be useful in understanding how patients adjust to persistent pain. This theory maintains that discrepancies between who people believe they are and who they would like to be or believe they ought to be are significant influences on people s emotional state. In self-discrepancy theory, the term actual self refers to how a person currently views him- or herself, ideal self refers to how a person would ideally like to be, and ought self refers to the attributes that a person believes he or she has an obligation to possess. This theory maintains that ideal self and ought self are self-guides that function as standards by which the actual self is evaluated and that discrepancies between actual self and ideal self or actual self and ought self may lead to increased psychological distress. Self-discrepancy theory also emphasizes the need to consider individuals beliefs about how others view them, namely, the individual s perceptions of the kind of person others ideally would like them to be (ideal-other self) or believe they ought to be (ought-other self). According to self-discrepancy theory, discrepancies between actual self and ideal-other self and between actual self and ought-other self can also be quite important in influencing psychological functioning and adjustment. 3,4 Researchers working in the area of selfdiscrepancy have developed a methodology for systematically assessing self-discrepancies, the Selves Questionnaire. 5 This semi-structured measure is relatively brief and can be administered in paper-and-pencil or interview format. The Selves Questionnaire was developed to assess actual, ideal, and ought selves from the individual s own standpoint and from the standpoint of others (i.e., ideal-own self, idealother self). Recent studies have used the Selves Questionnaire 6 in normal populations and in populations suffering from depression and anxiety. 7 These studies have revealed several important findings. First, persons who report experiencing a substantial discrepancy between actual self and ideal self are much more likely to feel depressed, sad, and discouraged than those reporting little or no actual-ideal discrepancy. 8 Second, persons who report experiencing a large discrepancy between actual self and ought self have been found to be more likely to report feeling anxious, worried, and fearful than those who reported little or no actual-ought discrepancy. Third, the associations between actual-ideal discrepancy and depressive affect and between actual-ought discrepancy and anxious affect have been obtained even after statistically controlling for the other type of selfdiscrepancy and other type of emotion state. 9 In the Strauman and Higgins 9 study, these associations were obtained when ideal-own and ideal-other self-discrepancies were combined to form a composite ideal self-discrepancy measure. The researchers also combined ought-own and ought-other self-discrepancies to form a composite ought self-discrepancy measure. In the present study, ideal discrepancy was used to denote ideal-own discrepancy; ought discrepancy was used to denote ought-own discrepancy. Discrepancies based on beliefs about the opinions of significant others were labeled as ideal-other and ought-other. No composite measures were used because we wanted to examine each self-discrepancy type individually. Although self-discrepancy measures have been applied in research with normal populations and depressed and anxious populations, to date they have not been used in patients suffering from chronic pain. Understanding self-discrepancies in persons having persistent pain is important for several reasons. First, it is possible that self-discrepancy may be associated with the intensity and unpleasantness of pain. Second, when pain persists, self-discrepancy may be related to higher levels of depression and psychological distress. Finally, newly developed interventions designed to reduce selfdiscrepancy (e.g., Self-System Therapy 10 )maybe beneficial for persons suffering from chronic pain. In order to understand the role of self-discrepancies in patients having persistent pain, however, a number of basic questions need to be addressed. First, can self-discrepancy be reliably assessed in persons having long-standing

3 Vol. 27 No. 3 March 2004 Self-Discrepancy and Chronic Low Back Pain 253 pain conditions such as chronic low back pain? Second, do each of the four types of self-discrepancies (actual self vs. ideal self, actual self vs. ought self, actual self vs. ideal-other self and actual self vs. ought-other self) measure a distinct type of self-discrepancy, or are they simply manifestations of a general type of self-discrepancy in patients suffering from chronic low back pain? Finally, how are self-discrepancies related to pain, depression, and psychological distress? The present study was designed to address these questions. Self-discrepancy was assessed in a sample of patients suffering from chronic low back pain, a common chronic pain condition. Methods Participants Participants were 93 patients (55.9% women) suffering from chronic low back pain (CLBP) and receiving treatment in the Duke University Medical Center Pain and Palliative Care Clinic. The average disease duration for the participants was 8.64 years ( 8.29 SD). The demographic information is presented in Table 1. Procedure and Measures Informed consent was obtained from all patients in the clinic setting. A series of measures was then given to all patients. Table 1 Demographic Information of the Study Population Variable % n Age a (years) Sex a Female Race a African American White Marital status b Married Education c High school High school High school a Based on responses from 93 participants. b Based on responses from 90 participants. c Based on responses from 88 participants. Self-Discrepancy. The interview version 11 of the Selves Questionnaire 5 was used to measure discrepancies between the attributes patients believed they have and the attributes they or others would like them to have or feel they ought to have. Patients generated lists of up to 10 traits for each self-domain: actual self, ideal self, ought self, ideal-other self, and ought-other self. Scoring of the Selves Questionnaire was conducted in the standardized fashion described by Higgins and colleagues. 5 Briefly, each attribute on the four self-state lists (ideal self, ought self, ideal-other self, ought-other self) was compared to each attribute on the actual self list using Webster s New World Roget s A Z Thesaurus. 12 Four types of attribute-pair associations were calculated: a) attributes synonymous with an actual self attribute were coded as matches; b) attributes that were synonymous with an actual self attribute but varied in degree were coded as mismatches of degree; c) attributes that were antonymous with an actual self attribute were coded as mismatches; and, d) attributes that were neither synonymous nor antonymous with any actual self attribute were coded as nonmatches. Next, the magnitude of discrepancy was quantified for each of the four types of self-discrepancy (i.e., actual self vs. ideal self, actual self vs. ought self, actual self vs. ideal-other self, actual self vs. ought-other self). Self-discrepancies were calculated by subtracting the number of matches (weighted by a factor of 1) from the number of mismatches of degree (weighted by a factor of 1) and the number of mismatches (weighted by a factor of 2). Nonmatches were not included in the calculations. Thus, positive scores represented higher levels of discrepancy and negative scores represented lower levels of discrepancy. Prior studies have provided strong support for the reliability and validity of the interview version of the Selves Questionnaire. Previous studies have reported inter-rater reliability ratings for the four types of self-discrepancy ratings ranging from 0.84 to and an overall inter-rater reliability of Moretti and Higgins 15 reported one-year test retest reliability of r 0.60 for actual self vs. ideal discrepancy and r 0.56 for actual self vs. ought discrepancy. The validity of this measure has been supported by numerous correlational and experimental studies. 16

4 254 Waters et al. Vol. 27 No. 3 March 2004 Pain Intensity. Pain was assessed using the McGill Pain Questionnaire (MPQ 17 ). The MPQ consists of a series of 20 sets of adjective pain descriptors. Patients were asked to check the one adjective in each category that best described their pain. Pain intensity was assessed using the Present Pain Intensity MPQ subscale score. Previous research has provided strong support for the reliability and validity of the MPQ (see Melzack and Katz 18 for a review of this literature). Depression. The Beck Depression Inventory (BDI 19 ) was used as a measure of depressive symptoms. The BDI, which is a 21-item selfreport inventory, assessed current degree of depressive symptomatology through items pertaining to cognitive, affective, motivational, and physiological areas of depressive symptomatology. The BDI has an internal consistency estimate of 0.86, test retest correlations ranging from 0.48 to 0.86 for varying time intervals, and strong support for the construct validity of this measure has been found. 19 The applicability of the BDI to patients with persistent pain has been demonstrated. 20 Psychological Distress. Symptoms of psychological distress were assessed using the Global Symptoms Index (GSI) of the SCL-90-R. 21 Patients were asked to rate the extent to which they had been bothered by each symptom during the past week using a scale ranging from 0 (not at all) to 4 (extremely). The 90-item, self-report inventory measured nine symptom dimensions: somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism. In this study, the GSI, which is the average of the perceived intensity scores for the number of symptoms reported (i.e., 90 if no responses are missing), was used to measure psychological distress experienced during the previous week. The reliability and validity of the GSI as a global measure of psychological distress has been established in prior studies. 21 Results Missing Data Due to time constraints, the majority of patients took several questionnaires home with them to complete and return in self-addressed, stamped envelopes. However, because not all of the participants completed all of the outcome measures, we compared the demographic information of those patients completing all measures to the patients with missing data. A series of t-tests and Chi-square tests of independence found that participants who completed all measures, on average, had some college education while participants who did not complete all measures were more likely to have ended their formal education after completing high school ( vs , M SD, respectively). No other statistically significant demographic differences were found. Next, a series of stepwise regression analyses were performed using the data from patients who had completed all measures. These analyses differed from the overall group analyses only in terms of finding no statistically significant association between measures of self-discrepancy and reported present pain intensity levels. This difference is likely due to low statistical power because of the reduced number of participants in the analysis. Thus, all reported results were based on data from the entire study population. Selves Questionnaire Interviewer Differences The Selves Questionnaire interviews were conducted by research assistants who received systematic training in conducting the semistructured interview. Training included lecture and role-playing sessions that provided guidelines for obtaining brief (i.e., one-word) descriptive trait information from the participants. We conducted a one-way analysis of variance (ANOVA) to identify potential interviewer differences in the number and types of discrepancies obtained. The one-way ANOVA found no statistically significant differences across interviewers in the number of actual ideal, actual idealother, actual ought and actual ought-other self-discrepancies obtained (F(5,90) 0.41, ns; F(5,89) 0.92, ns; F(5,87) 1.65, ns; and F(5,81) 0.42, ns, respectively. Inter-Rater Reliability In order to assess reliability of the scoring of the Selves Questionnaire, two raters scored each interview. Mean reliability of the coding was calculated by comparing the degree of agreement between ratings for each self-discrepancy type. Intraclass correlations (absolute

5 Vol. 27 No. 3 March 2004 Self-Discrepancy and Chronic Low Back Pain 255 accuracy) for the four self-discrepancy types ranged from Alphas in this range are considered to be excellent. The high alphas obtained in our study were the result of our structured training and rater adherence to strict scoring guidelines. Descriptive Analyses A series of analyses was performed to identify potential differences in self-discrepancy measures associated with sex, age, and pain duration. The results of t-tests found no statistically significant differences between women and men on self-reports of actual ideal, t(89) 1.51; actual ideal-other, t(88) 0.21; actual ought, t(86) 0.58; and actual ought-other self-discrepancies, t(80) Correlational analyses found no statistically significant associations between age and the self-discrepancy types(actual ideal, r 0.002; actual idealother, r 0.15; actual ought, r 0.07; and actual ought-other, r 0.06). Finally, the length of time since the onset of chronic low back pain was not significantly associated with actual ideal, actual ideal-other, actual ought, and actual ought-other self-discrepancies (r 0.01, r 0.11, r 0.02, and r 0.08, respectively). Table 2 presents descriptive information on the measures of actual ideal (n 91), actual ideal-other (n 90), actual ought (n 88), and actual ought-other (n 82) self-discrepanciesandtheoutcomemeasuresofpain(n 67), depression (n 70), and psychological distress (n 60). Negative numbers on the selfdiscrepancy measures denote fewer discrepancies between actual traits and ideal and ought traits. A test of within-subject effects found no significant differences in the magnitudes of the self-discrepancy types, F(3,78) Correlations between the four self-discrepancy types are presented in Table 3. All of the self-discrepancy types were significantly correlated with each other, with the magnitude of the correlations ranging from 0.24 to However, the magnitudes of the correlations indicated some unique variance in the quantitative estimates of the measures and provided evidence of specific self-discrepancy types. Relationships of Self-Discrepancy to Pain, Depression, and Psychological Distress A series of stepwise regression analyses was performed to evaluate the relative contributions of ideal, ideal-other, ought, and oughtother self-discrepancies to the prediction of pain, depression, and psychological distress. For each stepwise regression model, four selfdiscrepancy measures were entered in the following order: actual ideal, actual ideal-other, actual ought, actual ought-other. The rationale for this order is that historically the bulk of research on self-discrepancy and depression has focused on actual ideal discrepancies. Thus, it was important to enter the ideal discrepancies first and control for them prior to entering other self-discrepancy measures. Because actual ought and actual ought-other discrepancies have been more closely associated with heightened anxiety levels, we were interested in determining whether these discrepancies played a role in depression among CLBP patients. Table 4 provides a summary of the results of these analyses. Self-Discrepancy and Psychological Distress. As can be seen in Table 4, ought-other and ideal selfdiscrepancies contributed significantly to the variance in psychological distress (n 56). Discrepancies between patients actual traits and those traits they believed others felt they ought Table 2 Descriptive Statistics for Self-Discrepancy and Outcome Measures n Minimum Maximum Mean SD Actual ideal Actual ideal-other Actual ought Actual ought-other Present pain intensity Depression Psychological distress

6 256 Waters et al. Vol. 27 No. 3 March 2004 Table 3 Correlations Between Predictor and Outcome Actual Actual Actual Present Psychological Ideal-Other Ought Ought-Other Pain-Intensity Depression Distress Actual ideal Pearson Correlation a a a a b Sig. (2-tailed) n Actual ideal-other Pearson Correlation a b Sig. (2-tailed) n Actual ought Pearson Correlation a Sig. (2-tailed) n Actual ought-other Pearson Correlation b a a Sig. (2-tailed) n Present pain intensity Pearson Correlation a Sig. (2-tailed) n Depression Pearson Correlation a Sig. (2-tailed) n 60 a Correlation is significant at the 0.01 level (2-tailed). b Correlation is significant at the 0.05 level (2-tailed). to possess accounted for 20.9% of the variance in psychological distress scores. Discrepancies between the traits actually possessed and the traits patients would ideally like to possess accounted for an additional 6.3% of the variance in psychological distress scores. An overall R indicated a large effect size. 22 Self-Discrepancy and Depression. As can be seen in Table 4, ideal discrepancy explained the most variance in depression (n 63). Discrepancies between actual traits and the traits patients wished they possessed accounted for 14% of the variance in self-reported depression scores, denoting a moderate effect size. 22 Self-Discrepancy and Pain. As can be seen in Table 4, ought-other was the discrepancy type that explained the most variance in present pain intensity ratings (n 59). Patients with greater discrepancies between how they perceived themselves to actually be and their beliefs about how others felt they ought to be reported greater present pain intensity. Oughtother discrepancies accounted for 7.1% of the variance in present pain intensity levels, indicating a small effect size. 22 A Posteriori Analyses To further examine the relationship between self-discrepancy and depression, separate mean Table 4 Summary of Stepwise Regression Analyses Variable Incremental R 2 B SE B β P Dependent variable: Present pain intensity (n 59) Constant: Actual ought-other Dependent variable: Depression (n 63) Constant: Actual ideal Dependent variable: Psychological distress (n 56) Constant: Actual ought-other Actual ideal

7 Vol. 27 No. 3 March 2004 Self-Discrepancy and Chronic Low Back Pain 257 scores were calculated for the cognitive items (items 1 10) and somatic items (items 11 21) on the BDI. Separate stepwise regression analyses were performed to evaluate the relative contributions of actual ideal, actual ideal-other, actual ought, and actual ought-other self-discrepancies to the prediction of the cognitive and somatic items. As can be seen in Table 5, actual ideal discrepancy explained the most variance in the mean scores on the cognitive items and somatic items associated with depression (n 63). Discussion This study had several major findings. First, the findings indicate that self-discrepancies can be reliably assessed in patients with persistent pain using the Selves Questionnaire. The level of inter-rater reliability obtained in this study of chronic low back pain patients, in fact, is quite similar to that reported in prior studies of self-discrepancy in normal and depressed populations. This finding is important because it suggests that the Selves Questionnaire may provide a reliable and standard method of assessing selfdiscrepancies in persons having persistent pain. Second, this study found that the magnitude of the correlations among the four different types of self-discrepancy were moderate but not so high as to suggest that we were gathering multiple measures of one self-discrepancy construct. As observed in previous studies, although related, each self-discrepancy type seems to measure a unique aspect of self-discrepancy. Third, variations in the level and type of self-discrepancy were significantly related to depression, and psychological distress, also consistent with previous findings. One of the most interesting findings of this study was that self-discrepancy was related to psychological distress and depression in CLBP patients. We found support for the prediction of self-discrepancy theory that greater discrepancies between actual self and ideal self would be associated with increased levels of depression and that the association was evident for both the cognitive and somatic symptoms of depression. We also found an association between higher levels of actual ideal self-discrepancies and greater psychological distress. Actual oughtother self-discrepancies were also associated with greater psychological distress. Based on our findings, actual ideal self-discrepancies may contribute more to specific feelings of depression while actual ought-other self-discrepancies may contribute more to specific feelings of psychological distress. One explanation for why psychological distress is high in patients who experience discrepancies between their actual self and the person they believe significant others think they ought to be may lie in how patients with persistent pain interpret the feedback that they get from significant others (e.g., responses in the form of gestures, words, and actions). The theory of symbolic interactionism maintains that feedback that significant others provide influences views of the self. 23 According to this theory, individuals construct their self-concept, in part, by imagining and experiencing how significant others react to them and then internalizing this feedback into their own concept of their self. Thus, when patients having persistent pain perceive that the behaviors of significant others (e.g., being overly solicitous or overly criticizing) indicate that they are no longer able to be as independent and capable of fulfilling important responsibilities, these patients may adopt self-concepts that reflect this overly negative view. Symbolic interactionism would predict that, as this negative self-concept becomes entrenched, it tends to increase psychological distress. 24 Another interesting finding was that discrepancies between actual self and ought-other self were related to pain intensity in CLBP patients. Table 5 Summary of A Posteriori Stepwise Regression Analyses Variable Incremental R 2 B SE B β P Dependent variable: Depression: cognitive items (n 63) Constant: Actual ideal Dependent variable: Depression: somatic items (n 63) Constant: Actual ideal

8 258 Waters et al. Vol. 27 No. 3 March 2004 Patients who reported larger discrepancies between how they saw themselves (actual self) and how they believed others felt they ought to be (i.e., ought-other self-discrepancy) reported more intense pain. Two explanations for this association come to mind. First, perhaps greater experiences of pain result in a greater number of ought-other self-discrepancies. That is, increases in pain may make it difficult to maintain behaviors and engage in activities deemed important by family and other significant people in patients lives, resulting in discrepancies between patients perceptions of the traits they actually possess and the traits they believe others feel they ought to possess. Second, perhaps patients view their greater pain as a way of justifying the discrepancies they identify. Attributing the selfdiscrepancies to heightened pain levels may minimize individual responsibility and protect self-esteem, 25 especially for CLBP patients who may be experiencing a lot of negative feedback from significant others. Although the underlying reason for the association between actual ought-other self-discrepancies and pain remains to be determined, this finding fits with a growing body of literature noting the importance of the social context in understanding the pain experience. 26 This study found that two of the four types of self-discrepancy (i.e., actual self vs. ideal self, and actual self vs. ought-other self) were meaningfully related to measures of pain, depression, and psychological distress. We note that the same two self-discrepancies were the strongest predictors of distress in the original selfdiscrepancy research reported by Higgins and colleagues. 6 These findings provide evidence that the self-discrepancy type constructs are functionally distinct and suggest that participants are able to distinguish between ideal and ought traits as viewed from their own standpoint and the standpoint of others. The findings also underscore the need for using caution when combining separate self-discrepancy types to form composite self-guides. Limitations and Future Directions There are several limitations to the present study. First, the presence of missing data reduces statistical power and may have lessened our ability to accurately assess the impact of self-discrepancies on pain, depression, and psychological distress. Thus, additional studies with larger sample sizes are needed to identify the correlates of self-discrepancies in CLBP patients. Another limitation to the present study is the use of patient volunteers, which raises the issue of sampling bias and generalizability. Perhaps patients experiencing greater emotional distress associated with self-referential personality changes may be less likely to participate in a study that asks them to identify these selfdiscrepancies. Future investigations designed to target specific patient groups (e.g., clinically depressed CLBP patients) may provide additional insight into the relationships between self-discrepancies and other correlates of interest (e.g., medication use, pain, and depression). Finally, the correlational results collected in the present study do not allow us to infer causality. As such, we are unable to determine if increased self-discrepancy leads to increased pain, depression, and psychological distress or vice versa. Research paradigms, such as randomized control trials that examine the efficacy of interventions designed to alter self-discrepant feelings, should be useful in determining the direct effects of selfdiscrepancy on various outcome measures. For example, Self-System Therapy is a new approach for treating depression that directly addresses selfdiscrepancies that can lead to depression. 10 This novel treatment already has shown promising results, with overall efficacy comparable to cognitive therapy and superior efficacy for depressed individuals with significant problems in selfregulation and self-discrepant beliefs. 10 Conclusion To our knowledge, this study represents the first investigation to systematically examine selfdiscrepancy in a clinical population of patients suffering from a persistent pain condition. Taken together, these findings suggest that self-discrepancy is a useful concept in understanding pain, depression, and psychological distress in CLBP patients and support the need for future research in this area. Acknowledgments This work was supported, in part, by funds from the Fetzer Institute.

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