Several human studies have begun to evaluate the effects of rTMS protocols applied to the PFC on drug craving and consumption in nicotine. Johann and colleagues reported decreased levels of tobacco craving after single rTMS session over the left dorsolateral prefrontal cortex (DLPFC). In addition, a single session of rTMS over the right DLPFC can reduce cocaine craving. Eichhammer and colleagues in a cross-over, double-blind, placebo-controlled study demonstrated a reduction in cigarette consumption (measured 6 hours following the treatment) but craving levels remained unchanged after two rTMS sessions over the left DLPFC. Amiaz and collegues found that 10 days of high-frequency rTMS over the DLPFC reduced cigarette consumption and nicotine dependence. In addition, the rTMS blocked craving induced by smoking cues. However, the effect tended to dissipate after the 10 daily sessions and the reduction in cigarette consumption was not significant 6 months after treatment termination. Moreover, only 10% among those who responded to the treatment had totally quit smoking. Li et al treated subjects with real high-frequency rTMS or sham TMS over the DLPFC in two visits with 1 week between visits. The participants received cue exposure before and after rTMS. Stimulation of the left DLFPC with real rTMS reduced craving significantly from baseline. When compared with neutral cue craving, the effect of real TMS on cue craving was significantly greater than the effect of sham TMS. Rudction in subjective craving induced by TMS correlated positively with higher Fagerström Test for Nicotine Dependence score and more cigarettes smoked per day. These four studies demonstrate that high-frequency rTMS of the DLPFC can attenuate nicotine consumption and craving. However, the significance and duration of these effects are limited and further investigation is required to identify the appropriate stimulation parameters and targets needed to enhance the effectiveness of such treatment.