A preliminary study of the neural effects of behavioral therapy for substance use disorders

Abstract

Background: The mechanisms by which behavioral therapies for substance use disorders (SUDs) exert their effects and the components of treatment that contribute most to substance use outcome remain unclear. Disruptions to aspects of impulse control and attention have been hypothesized to contribute to the development and maintenance of addiction; moreover, alterations in these processes may underlie responses to treatment.

Methods: Individuals participating in a randomized clinical trial evaluating computer-assisted cognitive behavioral therapy (CBT) for substance abuse participated in fMRI Stroop before and after treatment. A non-substance-using comparison group performed the same task under test-retest conditions.

Results: The patient group demonstrated decreased Stroop-related BOLD signal in regions including the anterior cingulate, inferior frontal gyrus and midbrain at post-treatment relative to pre-treatment, and displayed a greater decrease in the subthalamic nucleus and surrounding regions compared to healthy controls following test-retest.

Conclusions: Behavioral therapies may be associated with reduction in substance use and effects on neural systems involved in cognitive control, impulsivity, motivation and attention.

Conflict of interest statement

Conflict of Interest Drs. DeVito, Carroll, Rounsaville, Kober, and Mr. Worhunsky declare no conflicts of interest. Dr. Potenza has received financial support or compensation for the following: consulted for and advised Boehringer Ingelheim; consulted for and has financial interests in Somaxon; received research support from the National Institutes of Health, Veteran’s Administration, Mohegan Sun Casino, the National Center for Responsible Gaming and its affiliated Institute for Research on Gambling Disorders, Forest Laboratories, Ortho-McNeil, Oy-Control/Biotie and Glaxo-SmithKline pharmaceuticals; participated in surveys, mailings, or telephone consultations related to drug addiction, impulse control disorders, or other health topics; consulted for law offices, governmental agencies and the federal public defender’s office in issues related to impulse control disorders; performed grant reviews for the National Institutes of Health and other agencies; given academic lectures in grand rounds, continuing medical education (CME) events, and other clinical or scientific venues; guest edited sections of journals; generated books or book chapters for publishers of mental health texts; and provides clinical care in the Connecticut Department of Mental Health and Addiction Services Problem Gambling Services Program.

Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Figures

Figure 1. Change in fMRI ‘Stroop-effect’

I. Change in fMRI BOLD signal across sessions on Stroop-effect (incongruent vs. congruent trials) contrast is displayed. Slice locations are indicated by MNI z levels. R: right side of brain images. Tx: treatment. Color bar indicates size of effect in t-values where blue tones indicate relative decreases in BOLD signal. i. Within-group changes across sessions were assessed with paired t-tests and a threshold of voxel-level p<0.005 with conjoint cluster-level pcorrected<0.05. ii. Group differences in change scores were assessed with a two sample t-test comparing change in BOLD signal activity following treatment (or re-test) masked for regions engaged by the SUD group at pre or post-treatment to a threshold of voxel-level p<0.005 and conjoint cluster extent of k=19. This cluster of significant interaction was saved as a mask in xjview and the mean signal intensity was extracted from the cluster mask region for incongruent vs. baseline and congruent vs. baseline contrasts from each participant at each session. The bar graph illustrates group means (±1 standard error of the mean) of the mean signal intensity from the cluster from each contrast at each time point.