Pain Influences Executive Function Via Depression in Adults with Sickle Cell Disease
Authors: Jonassaint Charles R , Bearden Donald L , O'Brien Julia A , Ono Kim E , Cohen Lindsey L , Sil Soumitri L , Dampier Carlton , Saah Elna , Novelli Enrico 
Published: June 2024

Abstract

Presentation Date: 6/9/2024
Presentation Start Time: 3:00:00 PM

Background
Patients with sickle cell disease (SCD) are highly vulnerable to pain, cognitive problems, and depression compared to their healthy peers. A rich literature has shown that pain affects cognitive function and that the mechanism of action through which this takes place (i.e., mediation) is, at least in part, emotional (e.g., depression). However, there is limited published research examining the impact of depression in SCD. In our study, we compared depression, pain, and executive function between a group of adults with SCD and a demographically matched control group. We then examined depression’s role as a mediator between pain and executive function.

Methods
Our study included 97 adult patients (Mage = 35.78 years, SD = 11.64; 55 females) with SCD receiving hematological care at a large medical center in the northeastern United States. The institution’s IRB approved the study, which involved collection of biopsychosocial and neuropsychological data from participants. Rating scales used in the current study included the Patient Health Questionnaire-9 (PHQ-9), Brief Pain Inventory (BPI), Digit Symbol Substitution Test (DSST), and Delis-Kaplan Executive Function System (DKEFS) Trails, Verbal Fluency, and Color-Word Interference subtests. In addition, we collected data using the same rating scales and tests from a demographically matched group of 84 healthy controls (Mage = 36.66, SD = 11.49; 50 females). However, not all participants in either group completed all scales/tests.

Results
After adjusting for covariates, the SCD group rated themselves as experiencing significantly more depression symptoms (PHQ-9) (t(91.564) = -3.832, p = &lt; .001) in daily life than the control group. The SCD group endorsed more pain on the BPI than the control group, which approached significance (p = .053) with a medium effect size (adjusted R2 = .193). Lack of significance was likely influenced by the small number of healthy controls who completed the BPI (n = 12). Independent samples t-tests corrected for familywise error rate using Bonferroni corrections showed that the SCD group significantly underperformed the control group on the DSST (t(143) = 3.728, p = &lt; .001), DKEFS Color Word Interference, Condition 3: Final Weighted Combined Score (t(140) = 3.526, p = &lt; .001), and DKEFS Color Word Interference and Condition 4: Final Weighted Combined Scaled Score (t(139) = 3.363, p = &lt; .001). Using Andrew Hayes’s PROCESS mediation macro, results showed a significant indirect effect such that depression (PHQ-9) fully mediated the association between pain (BPI) and performance on DSST, DKEFS Color Word Interference, Condition 3: Final Weighted Combined Score, and Color Word Interference and Condition 4: Final Weighted Combined Scaled Score (Table 1, Figure 1). The same mediation analyses were conducted for the healthy control group and did not indicate that depression mediated the association between pain and cognitive function.

Conclusions
As has been found in prior research, the SCD group in our study endorsed more depression and pain and exhibited more executive function problems than a group of healthy controls. Consistent with research in other chronic pain populations, depression significantly mediated the association between pain and executive function in adult patients with SCD. Depression may be a focus for treatment to improve executive function in patients with SCD, but more research is needed to substantiate these findings, including studies with larger samples.