Understanding drug craving: evidence from fMRI studies

Drug craving is a major crisis experienced by active or former drug abusers. The experience is characterised by an intense desire to abuse drugs for self-pleasure and satisfaction. This desire appears to be the main culprit behind the skyrocketing relapse rate. Neuroimaging has identified neural substrates associated with drug cravings. Here, we provide a mini-review of functional magnetic resonance imaging (fMRI) studies that have examined the brain regions associated with the common types of drug abuse — heroin, methamphetamine, and cocaine. Most studies use visual cues (that is drug-related images) to elicit brain responses in reward-related pathways. Studies have also focused on comparing brain activities between active drug abusers, drug-abstinent individuals, and healthy controls. Current evidence suggests that the dorsolateral prefrontal cortex (DLPFC) is associated with heroin craving, whereas the ventral striatum and medial prefrontal cortex (mPFC) underpin methamphetamine craving. Meanwhile, the hypothalamus is responsible for cocaine cravings. Compared to active drug abusers, drug-abstinent individuals demonstrated fewer brain activations when viewing drug-related images. The relationship between brain response and drug cravings is discussed in terms of brain functions and drug types. The findings offer valuable insights into the potential role of these brain areas in drug cravings and have important implications for drug addiction treatments.