The association between catastrophizing and craving in patients with chronic pain prescribed opioid therapy: A preliminary analysis

Abstract

A growing number of studies have shown that opioid craving (i.e., the perceived need or desire to consume opioids) is one of the strongest determinants of prescription opioid misuse in patients with chronic pain prescribed opioid therapy. To date, however, the factors that are associated with craving in patients with pain remain largely unexplored. Based on previous research, there is reason to believe that catastrophizing might be associated with heightened opioid craving.

Objectives

To test the hypothesis that catastrophizing would be associated with heightened craving in patients with chronic pain prescribed long-term opioid therapy.

Design & subjects, and methods

In this cross-sectional study, 109 patients with chronic pain were asked to provide self-reports of catastrophizing and craving. Patients also provided self-reports of pain intensity and depressive symptoms.

Results

We found that higher levels of catastrophizing were associated with higher levels of craving. Importantly, results of a regression analysis revealed that the association between catastrophizing and craving remained significant even after controlling for a host of demographic (i.e., age, sex), psychological (i.e., depressive symptoms), medical (i.e., pain intensity, pain duration), and medication regimen (i.e., opioid doses) variables.

Conclusions

Our preliminary findings provide valuable new insights into the determinants of craving in patients with pain. The finding that catastrophizing was associated with craving even after controlling for a host of demographic, psychological, medical, and medication regimen variables is particularly striking, and raises questions concerning the factors that underlie the association between catastrophizing and craving in patients prescribed opioid therapy.

1.0 Introduction

Over the past decade, there has been a substantial rise in the use of opioids for the treatment of chronic noncancer pain. Despite the potential benefits of opioid therapy, the rise in opioid use has been accompanied by escalating rates of prescription opioid misuse, which are up to 40-60% in clinic populations [1-4]. Prescription opioid misuse, which refers to the use of opioids in a manner other than how they are prescribed, may cause numerous adverse consequences, and may ultimately result in fatal opioid overdose [5-10]. Due to the alarming rates of prescription opioid misuse, researchers have turned their attention to the factors that may lead to opioid misuse in patients with chronic pain.

While a number of factors may contribute to prescription opioid misuse, emerging research indicates that opioid craving (i.e., the perceived need or desire to consume opioids) is one of the strongest determinants of opioid misuse. Among patients with chronic pain prescribed long-term opioid therapy, opioid craving has been found to be associated with various indices of prescription opioid misuse, including patient reports of opioid misuse [11-12], physician ratings of opioid misuse behaviors [13], and abnormal urine toxicology screens [13-14]. In a recent study conducted among patients with chronic pain prescribed opioids [11], craving has been found to mediate the association between negative affect (i.e., anxiety, depression) and opioid misuse, suggesting that craving might represent one of the final pathways through which psychologic and/or psychiatric factors may lead to opioid misuse in patients with pain.

In the substance use literature, the concept of craving has long been invoked to explain the development and persistence of substance use problems. Considerable research has been conducted on the determinants of craving, but mainly among illicit drug users (for a review, see [15-16]). In patients with pain, our understanding of craving has lagged behind, and the factors associated with prescription opioid craving remain largely unknown. Some studies have shown that levels of pain experienced by patients are only weakly associated with craving [11-13], which suggests that patients do not simply crave opioids because they experience high levels of pain. Psychological factors such as anxiety and depression (i.e., negative affect) have been found to be associated with heightened opioid craving [11, 13], but these factors cannot fully account for the inter-individual variability that has been observed in craving. Collectively, these studies suggest that an array of factors other than pain and negative affect might contribute to opioid craving in patients with pain prescribed opioids.

There is reason to believe that catastrophic thinking might be associated with heightened craving in patients with pain. Patients who are high in catastrophizing tend to ruminate about pain, to magnify the threat value of pain, and to experience feelings of helplessness when in pain [17-21]. In previous research, catastrophizing has been associated with increased analgesic use [22-25], and with a heightened risk for prescription opioid misuse [26-30]. To date, however, research has yet to specifically examine the association between catastrophizing and craving. Research examining the association between catastrophizing and craving has important clinical implications, and might provide further insights into the determinants of craving among patients with pain prescribed opioid therapy.

The objective of this brief report was to examine the association between catastrophizing and craving in a convenience sample (n = 109) of patients with chronic musculoskeletal pain prescribed long-term opioid therapy. We expected that patients with higher levels of catastrophizing would report higher levels of craving. The association between catastrophizing and craving was examined after controlling for a number of demographic, psychological, medical, and medication regimen variables.

2.0 Methods

2.1. Participants

The Human Subjects Committee of Brigham and Women’s Hospital (BWH) approved the study procedures and written informed consent was obtained from every participant. A convenience sample of 109 patients with chronic musculoskeletal pain was used in this study. Although this is a convenience sample, none of the patients used for the present analyses have been included in studies on opioid craving or misuse that have been previously published by our group.

At the time of the study, patients had experienced musculoskeletal pain for more than 6 months, were prescribed opioid medication, and were able to speak and understand English (see Table 1). Patients were excluded if they had any active medical illness (e.g., cancer, bone disease, heart disease, neurological disease), cognitive limitations that precluded providing self-report data, or any current (i.e., active) substance use problem. Study eligibility was determined through a structured phone interview conducted by a trained research assistant.

Table 1.

Sample characteristics

	Mean or %	SD
Age	49.4	8.0
Average daily opioid dose (ME)	128.2	154.7
Pain location
Back pain	81%
Neck pain	23%
Radiculating pain; lower	71%
Radiculating pain; upper	37%
Medication types
Opioids	100 %
NSAIDs	14 %
Muscle relaxants	20 %
Anticonvulsants	21 %
Antidepressants	20 %
Benzodiazepines	18 %
Pain severity (BPI)	6.0	1.6
Depressive symptoms (BDI)	16.1	6.4
Catastrophizing (PCS)	23.9	10.4
Craving index	1.4	1.6

Note. SD, Standard deviation; ME, Morphine equivalent (mg/d).

2.2. Measures

2.2.1 Demographic questionnaire

Patients were asked to complete a demographic questionnaire, which included information about age, gender, ethnicity, and history of substance use problems. Patients were also asked to report which opioid medication they were currently taking. Patients’ reports of medication were verified by a research assistant using the electronic medical record system, and published tables were used to convert daily opioid doses into morphine equivalents (ME).

2.2.2 Pain severity

The Brief Pain Inventory (BPI; [31]) was used as a measure of pain severity associated with patients’ musculoskeletal pain condition. On the BPI, patients are asked to rate their current level of pain on a numeric rating scale (NRS) with the endpoints 0 (no pain) and 10 (extreme pain). The BPI has been shown to be a reliable and valid measure of pain severity among patients with chronic pain [29, 31-32].

2.2.3 Craving

Craving was assessed using the 2 craving items from the Screener and Opioid Assessment for Patients with Pain-Revised (SOAPP-R; [14]). The SOAPP-R is a self-report questionnaire validated for patients with chronic pain, and designed to assess patients’ risk for prescription opioid misuse. Craving items on the SOAPP-R are rated from 0 (never) to 4 (very often) (e.g., item # 11: How often have you felt a craving for medication? item #15: How often have you felt consumed by the need to get pain medication?). These craving items have been found to have good reliability and predictive validity, and have been shown to be significant predictors of prescription opioid misuse outcomes derived on the basis of instruments such as the Prescription Drug Use Questionnaire (PDUQ), the Prescription Opioid Therapy Questionnaire (POTQ), and urine toxicology screens [12-14, 33].

2.2.4 Pain Catastrophizing

The Pain Catastrophizing Scale (PCS;[20]) was used as a measure of pain catastrophizing. The PCS contains 13 items describing different thoughts and feelings that individuals may experience when they are in pain. Participants are asked to reflect on past painful experiences and to indicate the degree to which they experienced each of the 13 thoughts or feelings when experiencing pain, on a 5-point scale ranging from (0) not at all to (4) all the time. The PCS yields a total score, and separate scores for the three PCS subscales: rumination, magnification, helplessness. Several studies have supported the reliability and the validity of the PCS among patients with chronic pain [17-19, 21, 34].

2.2.5 Depressive symptoms

The Beck Depression Inventory (BDI-II; [35]) was used as a measure of depressive symptomatology. The BDI consists of 21 items describing various symptoms of depression, and respondents choose statements that describe how they have been feeling over the past two weeks. Responses are summed to yield an overall index of depressive symptoms. The BDI has been shown to be a reliable and valid index of depressive symptoms in patients with chronic pain [36-38].

2.5 Data reduction and analysis

All analyses were conducted using SPSS 20 (SPSS, Inc., Chicago, IL, USA). A craving index was computed by averaging patients’ scores from the craving items on the SOAPP-R. Descriptive statistics were reported as percentages, means, and standard deviations. A Pearson correlation was first conducted to examine the association between catastrophizing (PCS) and the craving index. A series of Pearson correlations were then computed to examine associations between PCS subscales (i.e., rumination, magnification, helplessness) and the craving index. A follow-up hierarchical multiple regression analysis was used to examine if catastrophizing (total PCS) was associated with craving after controlling for demographic (i.e., sex, age), psychological (i.e., depressive symptoms, history of substance use problems), medical (i.e., pain intensity, pain duration), and medication regimen (i.e., daily opioid dose) variables.

3.0 Results

Descriptive statistics for patient characteristics and all study measures are presented in Table 1. Results of a correlation analysis revealed a significant positive correlation between the PCS and the craving index (r = .41, p < .001), indicating that higher levels of catastrophizing were associated with higher levels of craving.

Three separate correlations were computed between PCS subscales (i.e., rumination, magnification, helplessness) and the craving index. Results of correlation analyses revealed that craving was associated with higher scores on the rumination (r = .44, p < .001), magnification (r = .35, p < .01), and helplessness (r = .31, p < .01) subscales. Results of a series of Steiger’s Z-tests indicated that the magnitude of correlation coefficients did not differ across PCS subscales (all p’s > .05).

A hierarchical multiple regression analysis was conducted to examine the relative (i.e., unique) association between catastrophizing (total PCS scores) and craving. In this analysis, patients’ sex and age were entered in the first step of the analysis, but failed to contribute significantly to the prediction of craving scores, R = .01, F (2, 106) = .01, ns. History of substance use problems, daily opioid doses, levels of pain (BPI), and depressive symptoms (BDI) were entered in the second step of the analysis and contributed significantly to the prediction of craving scores, R² change = .16, F (4, 102) = 4.4, p < .01. Catastrophizing (total PCS) was entered in the final step of the analysis and contributed significant ‘unique’ variance to the prediction of craving, R² change = .09, F (1, 101) = 11.2, p < .01.

4.0 Discussion

There is a growing number of studies showing that opioid craving is one of the strongest determinants of prescription opioid misuse in patients with chronic pain prescribed long-term opioid therapy. To date, however, the factors that are associated with opioid craving in patients with pain remain largely unexplored. The objective of this brief report was to examine the association between catastrophizing and opioid craving in a sample of chronic pain patients prescribed long-term opioid therapy.

In our study, we found that higher levels of catastrophizing were associated with higher levels of craving. Importantly, results of a regression analysis revealed that the association between catastrophizing and craving remained significant even after controlling for a host of demographic, psychological, medical, and medication regimen variables. To our knowledge, this is the first study to show that catastrophizing is associated with heightened reports of craving in patients with chronic pain. While catastrophizing has previously been found to be associated with an increased risk for opioid misuse in patients with pain [26-30], this is the first study to specifically examine the association between catastrophizing and craving. The finding that catastrophizing was associated with craving even after accounting for patients’ depressive symptoms (i.e., negative affect) is particularly striking. While negative affect is known to be an important dimension of catastrophizing [17-18, 39-40], our results suggest that specific aspects of catastrophizing that are independent of patients’ affective/emotional states might contribute to the association between catastrophizing and craving.

There are a number of psychological factors independent of those included in our study that might account for the observed association between catastrophizing and craving. First, it is possible that high catastrophizers possess certain psychological characteristics that may heighten the experience of craving. For example, it is possible that catastrophizers have difficulty coping with pain, which in turn might enhance craving and/or the perceived need to use medication. In previous studies, high catastrophizers have been found to have poor pain-related coping skills (for a review, see [17-18, 21], and poor coping has been linked to heightened reports of craving in patients with substance use problems [41-43]. Similarly, it is possible that high catastrophizers hold pre-existing personality traits that increase their propensity to experience craving. For example, catastrophizing has been associated with heightened impulsivity and sensation-seeking [44-45], two personality traits that have been consistently associated with reports of craving in patients with substance use problems [46-48]. Finally, catastrophic thinking represents one of the core features of borderline personality disorder [49-53], a psychiatric condition that frequently co-occurs with substance use problems (for a review, see [54]). It is thus possible that the influence of catastrophizing on craving is due, in part, to personality or psychiatric issues characterizing chronic pain patients with high levels of catastrophizing.

There are also a number of biological explanations that could possibly account for the association between catastrophizing and craving. One possibility is that catastrophizing influences the central nervous system (CNS) processes that are involved in the regulation of craving. Previous research has shown that drug craving is regulated by a host of CNS processes that may be directly or indirectly influenced by psychological factors, such as mood, affect, or catastrophizing [55-59]. Evidence from brain imaging research indicates that the experience of craving is primarily regulated through mesolimbic pathways and brain regions such as the nucleus accumbens, the amygdala, the prefrontal cortex, the insula, and the anterior cingulate cortex (for a review, see [5, 57, 60]). The mesolimbic system shares neural pathways with some of the brain areas involved in the regulation of catastrophizing [5, 61-64], providing a neural basis for the influence of catastrophizing on craving. Another possible explanation is that patients with high levels of catastrophizing experience high levels of opioid craving due to a dysfunction in endogenous opioidergic systems. Previous studies conducted among patients with substance use disorders have shown that abnormal μ-opioid receptor binding activity [59, 65-66] and lower circulating beta-endorphin levels [67-68] may contribute to enhancing craving. Interestingly, there is research suggesting that catastrophizing may alter the functioning of endogenous opioid systems [18, 40, 69], which could explain why patients high in catastrophizing tend to experience high levels of craving. Future research will be needed to elucidate the biological mechanisms that underlie the association between catastrophizing and craving in patients with pain. In addition to opioidergic systems, future research should explore the potential role played by dopaminergic, serotonergic, and noradrenergic systems in the catastrophizing-craving association. All these systems have been found to be involved in the experience of craving among individuals with substance use disorders (for a review, see [15, 55, 70-71]), and may be modulated by a wide range of psychological factors and personality dispositions [64, 67, 72-80].

There are limitations to the current study that must be considered when interpreting our findings. First, the cross-sectional nature of our study design precludes any firm conclusions regarding the directionality of associations between study variables. Second, our analyses were performed using a convenience sample, which limited our explanatory reach in accounting for some of the findings that were reported in the present study. Third, patients included in our study were recruited from a tertiary pain center and were taking relatively high doses of opioids (i.e., average daily morphine equivalent dose > 100 mg), which places limits on the generalizability of our findings.

Despite these limitations, our findings provide valuable new insights into the factors that may influence opioid craving in patients prescribed opioids. The finding that catastrophizing was associated with craving even after controlling for a host of demographic, psychological, medical, and medication regimen variables is particularly robust, and warrants further attention. Our findings also lend insights into the association that has previously been observed between catastrophizing and heightened risk for prescription opioid misuse in patients with chronic pain [26-30]. Although speculative, our findings suggest that craving might represent one of the factors by which catastrophizing may lead to prescription opioid misuse. Research should be conducted to examine whether craving is responsible (i.e., mediates) the association between catastrophizing and prescription opioid misuse in patients with pain. As discussed earlier, further research will also be needed to examine the specific biological and psychological factors that underlie the association between catastrophizing and craving. Advances in this domain could have important theoretical and clinical implications, and could ultimately lead to reduced rates of prescription opioid misuse in patients with chronic pain.

Table 2.

Hierarchical multiple regression analysis examining the unique association between catastrophizing and craving

	B	R2	R2 change	F change
Step 1		.01	.01	.01
Sex	−.01
Age	−.01
Step 2		.17	.16	4.4 **
Hx. Sub. use problems	.02
Daily opioid doses	.03
Pain intensity (BPI)	.27**
Depressive sx. (BDI)	.32 **
Step 3		.25	.09	11.2 **
Catastrophizing (PCS)	.33**

Note. Opioid dose represents the average daily opioid dose (morphine equivalent).

B, Standardized Beta coefficients.

^*p < .05

^**p < .01