Functional neural changes following behavioral therapies and disulfiram for cocaine dependence

Abstract

A growing literature exists on neural correlates of treatment outcome. However, different types-or components of-treatment have distinct theorized mechanisms of action. And it is not yet known how changes in neural activity across treatment relate to engagement in different treatment components. Participants with cocaine use disorders in a randomized clinical trial received cognitive-behavioral therapy (CBT) plus, in a 2 × 2 design, contingency management (CM) or no CM, and disulfiram or placebo. Participants performed a functional MRI Stroop task, a measure of cognitive control, at the beginning of and after the 12-week treatment. Analyses assessed changes in Stroop-related neural activity within the sample overall and assessed how changes in Stroop-related activity correlated with measures of treatment process specific to each form of treatment (i.e., participation in CBT sessions, receipt of CM prizes, administration of disulfiram pills). Within the sample overall, compared with beginning of treatment, posttreatment Stroop-related neural activity was diminished in the hippocampus, thalamus, cingulate, precentral, post- and precentral gyrus, and precuneus and culmen regions (pFWE < .05). In separate whole-brain correlation analyses, greater reductions in Stroop-related activity were associated with more treatment engagement-"CBT sessions" with the precentral gyrus, inferior parietal lobule, and middle and medial frontal gyrus; "CM prizes" with the postcentral frontal gyrus. Disulfiram "medication days" were not associated with changes in Stroop-related activity. Findings suggest that key process indicators of CBT and CM may be associated with functional changes in cognitive-control-related neurocircuitry. (PsycINFO Database Record

Figure 1. Reduced Stroop-related Activity at Post-Treatment vs. Beginning-of-Treatment

A. Changes in Stroop effect-related activity (incongruent>congruent trials) at post-treatment versus beginning-of-treatment in the sample overall (N=26). Blue indicates regions with lower Stroop-related BOLD signal at post-treatment relative to beginning-of-treatment. fMRI results are family-wise-error-corrected for multiple comparisons at pFWE<.05. For additional details see Table 3A. For full results, see Supplementary Figure 2. B. The mean extracted betas from significant clusters (significant clusters shown in section A, in full Supplementary Figure 2 and reported in Table 3A). Mean betas are presented for each trial type (incongruent, congruent) and time point (beginning-of-treatment, post-treatment), relative to all unmodeled baseline. L= left, R= right. Bars are in following order: Congruent (Beginning-of-Treatment), Incongruent (Beginning-of-Treatment), Congruent (Post-Treatment), Incongruent (Post-Treatment). Fill color indicates trial type (white= congruent; grey= incongruent). Border color indicates time point (black=Beginning-of-Treatment; red= Post-Treatment). Error bars represent +/− 1 SEM.

Figure 2. Correlation between Change in Stroop effect and Treatment Engagement and Outcome

Rank-order whole brain correlations between change in Stroop effect-related activity at post-treatment versus beginning-of-treatment ((post incongruent- post congruent)-(pre incongruent- pre congruent)) and (A) number of cognitive behavioral therapy (CBT) sessions attended (N=26); (B) number of contingency management (CM) prizes received, within group randomized to CM (N=14); (C) percent days of self-reported days of cocaine abstinence during treatment. Blue regions indicate inverse correlations showing lower Stroop-related activity at post- vs. beginning-of-treatment associated with more treatment engagement. Red regions indicate positive correlations showing higher Stroop-related activity at post- versus beginning-of-treatment associated with more cocaine abstinence. Scatter plots show extracted rank order correlations from each significant cluster (see Table 3B). fMRI results are family-wise-error-corrected for multiple comparisons at pFWE<.05. For full sliceout of results, see Supplementary Figure 3.