Understanding the treatment of attention deficit hyperactivity disorder in newly diagnosed adult patients in general practice: a UK database study

Background: Adult attention deficit hyperactivity disorder (ADHD) has been largely ignored in psychiatric and general practice guidance until recently. Adult ADHD has a high social and medical burden, but health care is not well described in the UK. The main study objective was to evaluate a primary care adult ADHD population in terms of prescribing and health care contact rates. Methods: This was a retrospective observational study using data from the Clinical Practice Research Database from January 1, 2002 to July 31, 2011. Adult patients with an incident ADHD diagnosis or ADHD medication were identified as having been free of ADHD medication or diagnoses in the previous 2 years. Patients were followed for 12-24 months after diagnosis. Results: Of the 663 patients with ADHD in the cohort, 54.1% were prescribed ADHD medication during the observation period. During the first 6 months, 34.2% of patients initiated methylphenidates and 14.0% atomoxetine. In total, 36.3% patients were referred to secondary care psychiatry during observation, with the remaining population (63.7%) never having a referral. Most of the referrals were before diagnosis in primary care. At the end of the observation period, 16.2% of patients were on antipsychotics, 17.3% hypnotics, and 34.8% antidepressants or anxiolytics; however, some patients appeared to be prescribed antipsychotic or antidepressant medications even if they did not have an observable diagnosis in their records. Health care contact rates (general practitioner or hospital) increased by 39.2% post-diagnosis (incidence rate ratio: 1.39; 95% confidence interval: 1.32, 1.47), which may be related to the need for medication monitoring and titration. Conclusion: This study has shown in primary care that there is relatively low use of ADHD medication, low referrals into secondary care, high rates of usage of psychiatric non-ADHD medications for different indications, and an increasing burden in terms of health care contacts in adult ADHD patients post-diagnosis.