Craving consists of cognitive, emotional, and behavioral elements related to a desire to drink alcohol, and can be experienced during intoxication, withdrawal, and/or prior to relapse. Different types of craving are hypothesized to be associated with different neurotransmitter systems. For example, reward craving may be mediated by dopamine and opioids, obsessive craving by serotonin, and relief craving by glutamate. A new study used magnetic resonance spectroscopy (1H-MRS) to examine the correlation between craving and glutamate levels in the left dorsolateral prefrontal cortex (LDLPFC) of patients with alcohol use disorders (AUDs).