Background and Objectives: The objective of the present study was to obtain information about the prevalence of addiction disorders in ADHD patients in a German study population, to compare the prevalence of addiction disorders in ADHD patients to that in the normal population according to the German Epidemiological Addiction Survey, and to determine which drugs are consumed most by ADHD patients. Participants: The sample consisted of 61 patients (average age 35.11 ± 9.33 years) from our ADHD consultation who were consecutively included in our study over a period of 12 months. Measurements: We diagnosed ADHD according to DSM-IV-R and by assessing the WURS-k, CAARS and BROWN ADD scales. For diagnosing addiction we conducted the EuropASI, the IDCL, the QOD and the FTNA. For differential diagnosis we assessed the SCL-K. Results: About half of our study population of ADHD patients were diagnosed with a dependence disorder (50.8%, n = 31). Twenty one dot three percent (n = 13) were suffering from an alcohol dependence, 13.1% (n = 8) from a substance use disorder (SUD) and 18% (n = 11) from a combination of both addictions. The drug consumed most commonly by ADHD paALCOHOL AND DRUG DEPENDENCE IN ADULTS WITH ATTENTION-DEFICIT... 151