**3. DBS for the treatment of addiction**

The use of deep brain stimulation (DBS) for the treatment of addiction was fortuitous, starting from observation in some PD patients the escalation of their intake of dopamine replacement therapeutics in a manner similar in some ways to addiction, a phenomenon known as dopamine dysregulation syndrome (DDS) [18]. Witjas et al. in 2005 described a reduction of the behavioral disorders as well as addiction to dopaminergic treatment in two PD patients who underwent subthalamic nucleus (STN)-DBS [19]. Subsequently, other studies confirmed the resolution of dopamine dysregulation syndrome following STN-DBS for PD [20–22]. In rat models it was demonstrated that lesions of the STN decrease motivation to take cocaine suggesting that STN-DBS might be a therapeutic option for addiction [23]. In 2007, during a DBS procedure of the nucleus accumbens (NAcc) in a heavy drinker patient with agoraphobia and panic attacks, a rapid reduction of the alcohol intake of the patient was observed [24]. Similarly, three additional patients receiving accumbens DBS for other indications were reported to have spontaneously quit smoking [25].
