The analysis of the utilization of mental healthcare services using routine data provided by statutory health insurance companies and pension funds is a way to assess the frequency of service use, the distribution of the service use among various healthcare settings (inpatients vs. outpatients, rehabilitation according mainly to the German Social Code Book IX vs. curative treatment according to the German Social Code Book V [note that some elements of rehabilitation are financed according to Social Code Book V as well]) and medical disciplines (psychiatry and psychosomatic medicine vs. somatic disciplines and general medicine). In addition, these data can provide information on the social consequences of mental disorders, as assessed by the number of cases and the duration of sick leave or case numbers of early retirement due to mental disorders. In this study, healthcare utilization data from 10 million Germans were analysed. Within a 3 year observation period (2005-2007), about one-third (approx. 3.3 million) persons had a contact with a healthcare service due to a diagnosis of the ICD-10 groups F0-F5. Given the large number of persons with depression in Germany, the initial results of an analysis of mental healthcare utilization due to depression are presented here. Among the study group of 3.3 million Germans with mental healthcare utilization within the observation period, 1.4 million had at least one contact to healthcare system due to the diagnosis of depression. In most cases, depression was diagnosed without specification of severity. It was found that non-psychiatric disciplines like general practitioners were the most frequently used providers in outpatient mental health care, whereas inpatient treatment predominantly occurred in psychiatric departments. For those persons with depression for which a severity-indicating ICD-10 code was used, it was found that utilization of psychiatric and psychosomatic disciplines increased in both in- and outpatient treatment compared to use of general medical facilities with more severe depression. Specialists for psychosomatic medicine and psychological psychotherapists predominantly treated cases of mild and moderate depression, whereas severe cases were mostly cared for by psychiatrists or psychiatric departments.