Transcutaneous Non-invasive Vagus Nerve Stimulation (t-VNS) in the Treatment of Schizophrenia

Inclusion Criteria: * Diagnosis of a schizophrenic disorder (F20 according to ICD-10),duration of disease ≥ 12 months * Appliance of the t-VNS® medical device according to the manual Exclusion Criteria: * Improvent of the PANSS score within the period of 2 - 4 weeks from screening to the baseline * Pregnancy * Bronchial asthhma in medical history * clinically relevant internistic, neurological or psychiatric diseases * abuse of drugs or alcohol until 4 weeks to enrollment * Traumatic brain injury in medical history as well as invasive and non-invasive methods of treatment (e.g. tumor surgery (Gammma knife surgery)) * indication of structural impairment of the basal ganglia or the brain stem * malformations of the pinna * further circumstances that at the discretion of the investigator will not allow to include the subject into the clinical study