The fMRI activation patterns in right insular, posterior cingulate, and temporal cortex correctly predicted 20 out of 22 subjects who did not relapse, and 17 out of 18 subjects who did. A Cox regression analysis revealed that the combination of right middle frontal gyrus, middle temporal gyrus, and posterior cingulate activation best predicted the time to relapse. In total, this is the first investigation to show that fMRI can be used to predict relapse in substance dependent individuals. It is likely that relapse corresponds with less activation in structures that are critical for decision-making, and thus poor decision-making sets the stage for relapse. The insular cortex may act through the interoceptive system to influence ability to differentiate between good versus poor choices, while the inferior parietal lobule may play a role in poor assessment of decision-making situations and subsequent reliance on habitual behavior. Overall, substance dependent adults show brain patterns that can be used to predict whether and when relapse may occur. Future studies are needed to determine if this is true for adolescents, and whether brain activation patterns can be used to evaluate an individuals’ readiness for treatment completion or treatment response.
