"Mobility" is a contributing factor in today's society. Drug dependence displays not only a medical but also an economic problem: Especially for an intended reintegration of a drug dependant patient in maintenance therapy the possession of a driving licence could be decisive for a job allocation and therefore the intended reintegration to society.

Subject of this study was to verify if patients under substitution therapy with R, S- Methadone, S- Methadone, Buprenorphine and Buprenorphine plus Naloxone are just as fit to drive a car as a non drug dependent person.

For this investigation we compared 121 drug dependent patients in stable maintenance therapy for a minimum of two years without consumption of any other psychotropic substances than their maintenance drug (including THC) with non- drug dependant subjects of the same gender, age and level of education.

This is the largest study on this topic worldwide. The neuro- cognitive working order was tested by means of the "Vienna Test System" an objective, reliable and valid test quantifying reaction time, attention efficiency, concentration, maximum resilience and orientation. Current use of any other psychotropic substance or alcohol just as any serious illness (including psychiatric diseases, except for an effectively treated depression) lead to exclusion from this study.

Inclusion Criteria:

• Drug dependent patients in stable maintenance therapy for a minimum of two years without consumption of any other psychotropic substances than their maintenance drug (including THC)
• Written agreement on attending this study after full clarification
• majority

Exclusion Criteria:

• Patients, who do not approve or are not able to approve, to this study
• Patients, who are not legally competent
• Patients in emergency situations
• Patients under age
• Consumption of any other psychotropic substances than the maintenance drug
• Severe illnesses p.e. malignant diseases, serious psychiatric illness

drug dependent patients in stable maintenance therapy