The main objective of this study is to assess the efficacy of bilateral deep brain stimulation (DBS) of the Nucleus accumbens (NAc) as a novel treatment in severe opioid addiction. The included patients have been treated so far with a substitute in form of methadone.

Our hypothesis is that bilateral DBS of the NAc will significantly reduce the craving for heroin and thus enable the patients to decrease their Levomethadone-dosage substantially.

Inclusion Criteria:

• Age > 18 years
• Proficiency in the German language
• Long lasting heroin addiction (fulfilled diagnostic-criteria according to DSM-IV,ICD-10)
• At least one detoxication-treatment without a long-term period of abstinence has already taken place
• Long-term inpatient treatment to support abstinence have occurred
• Free patient's decision / Informed Consent (existing comprehensive ability in meaning, methodology and execution of the study and ability of acceptance)
• If prior medication, stable dosage of psychopharmacological drugs over the last three months, which shall, after checking be retained during the study
• Substitution treatment with constant dose within the last three months before study inclusion

Exclusion Criteria:

• Hospitalization by PsychKG
• Clinical relevant psychiatric comorbidity (schizophrenic psychoses, bipolar affective diseases, severe personality disorder)
• Contraindications of a MRI-examination, e.g. implanted cardiac pacemaker/ heart defibrillator
• Current and in the last six months existent paranoid-hallucinated symptomatology
• Foreign aggressiveness in the last six months
• Verbal IQ < 85 (evaluated with the German Mehrfachauswahl-Intelligenz-Test (MWT-A/B))
• Stereotactic respectively neurosurgical intervention in the past
• Neoplastical neurological diseases
• Contraindications of a stereotactic operation, e.g. increased bleeding-disposition, cerebrovascular diseases (e.g. arteriovenous malfunction, aneurysms, systemic vascular diseases)
• Serious and instable organic diseases (e.g. instable coronal heart disease)
• tested positively for HIV
• pregnancy and/or lactation