Incubation of cocaine craving after withdrawal

Relapse to cocaine addiction is frequently associated with subjective reports of craving, a poorly understood state that precedes and accompanies cocaine-seeking behaviours1. It has been suggested2 that over the first few weeks of withdrawal from cocaine, human addicts become sensitized to drug-associated environmental cues that act as external stimuli for craving, although the evidence for this is inconsistent3. Here we provide behavioural evidence from laboratory animals suggesting that the onset of craving is delayed and that craving does not decay, but rather increases progressively, over a two-month withdrawal period.