OBJECTIVES: To put the apparent rise of the administrative prevalence of attention-deficit/hyperactivity disorder (ADHD) in the region of Nordbaden in Southwestern Germany into context by analyzing the most frequently diagnosed mental health problems in this population. METHODS: The complete claims database of the organization of physicians registered with statutory health insurance [SHI] (Kassenaerztliche Vereinigung, KV) in Nordbaden/Germany was available for analysis, covering the total regional population enrolled in SHI (>2.2 million).  The dataset for years 2003 to 2009 was reorganized as to allow patient-centered evaluation.  RESULTS: Most frequently diagnosed mental health problems in 2009 were depressive episodes (ICD-10 code F32.9), with an overall administrative 12-months prevalence rate of 8.3%; unspecified somatoform disorders (F45.9), 4.8%; harmful use of tobacco (F17.1), 3.4%; neurasthenia (F48.0), 2.3%; and adjustment disorders (F43.2), 2.2%.  Uncomplicated hyperkinetic disorder (HKD, F90.0) was the number one reason for contacts with health care providers in children (age group 6-12 years, 7.2%) and adolescents (13-17 years, 3.7%), reported more than twice as often as the next frequently diagnosed mental health problems, namely various developmental, speech, and adjustment disorders.  In preschoolers, speech and developmental problems were diagnosed more frequently than HKD (1.0%).  From 2003 to 2009, the administrative prevalence of ADHD (HKD/F90.0 and hyperkinetic conduct disorder, HKCD/F90.1, combined) increased by 79%, i.e., from 0.53% in 2003 to 0.95% (overall; 6-12 years, 8.0%; 13-17 years, 4.2%) in 2009.  Notwithstanding lower absolute numbers, ADHD prevalence in adults increased more than fourfold, from 0.04% (2003) to 0.17% (2009). CONCLUSIONS: By 2009, ADHD represented the leading mental health related cause of service utilization among children and adolescents in Nordbaden.  The present analysis underscores the need for in-depth research addressing the quality, cost, cost effectiveness, and broader economic implications of health and social service provision for children, adolescents, and adults with a diagnosis of ADHD.