Craving to quit: psychological models and neurobiological mechanisms of mindfulness training as treatment for addictions

Abstract

Humans suffer heavily from substance use disorders and other addictions. Despite much effort that has been put into understanding the mechanisms of the addictive process, treatment strategies have remained suboptimal over the past several decades. Mindfulness training, which is based on ancient Buddhist models of human suffering, has recently shown preliminary efficacy in treating addictions. These early models show remarkable similarity to current models of the addictive process, especially in their overlap with operant conditioning (positive and negative reinforcement). Further, they may provide explanatory power for the mechanisms of mindfulness training, including its effects on core addictive elements, such as craving, and the underlying neurobiological processes that may be active therein. In this review, using smoking as an example, we will highlight similarities between ancient and modern views of the addictive process, review studies of mindfulness training for addictions and their effects on craving and other components of this process, and discuss recent neuroimaging findings that may inform our understanding of the neural mechanisms of mindfulness training.

Figure 1. Associative learning “addictive loop” for nicotine dependence

a) Smoking becomes associated with positive (green) and negative (red) affect through positive and negative reinforcement. Cues that trigger these states (gray arrows) lead to cue-induced craving, furthering this process, which through repetition becomes automated over time. Strategies that teach avoidance of cues or substitute behaviors do not directly dismantle the core addictive loop (black arrows), leaving individuals vulnerable to relapse to smoking. b) Limitation of current treatment paradigms in dismantling the addictive loop: avoidance of cues dampens input into the addictive loop (black arrows). While substitute behaviors, such as eating candy or engaging in an activity that distracts and individual such as going for a walk (blue arrows) circumvent the targeted addictive behavior. However, neither of these strategies dismantles the addictive loop at its core. Copyright 2011 Judson Brewer. Reprinted with permission of author.

Figure 2. Early models of addiction: dependent origination

Copyright 2011 Judson Brewer. Reprinted with permission of author.

Figure 3. Reduction in craving lags behind smoking abstinence

Individuals who maintained smoking abstinence at 4-Months (solid lines) reported similar craving levels to those who did not achieve abstinence (dashed line) at the end of treatment. Craving continued to drop for abstainers, but increased concomitant with smoking for non-abstainers. Adapted from Elwafi et. al. (2012, under review).