Tobacco addiction is treatable with behavioral and pharmacological means, but results are often less than optimal. Transcranial direct current stimulation is a new non-invasive technique that applies weak electrical currents through the skull and has been shown to alter the excitability of certain brain areas. It is currently being tried in disorders where there is abnormal brain excitability, such as epilepsy and depression. A few studies have also been able to diminish drug craving, suggesting that brain excitability might also be altered in drug addiction.