PHARMACOGENETIC PANEL TESTING IN SPECIALIZED PSYCHIATRIC CARE - PILOT STUDY

ABSTRACT Background: Psychiatric medication response and adverse effects show substantial interindividual variability, partly due to genetic differences in drug metabolizing enzymes, which pharmacogenetics seeks to address to optimize treatment. Although its clinical use has expanded in psychiatry and may improve outcomes and cost-effectiveness, less is known about patient selection and real-world implementation. This pilot study describes pharmacogenetic panel testing in specialized psychiatric care, focusing on patient selection, underlying clinical factors and the testing process timeline. Methods: The study included participants from Oulu University Hospital specialized psychiatric care with individuals identified via the Nordlab laboratory information system. Data was collected manually from the ESKO electronic health record system for participants over 13 years of age who were tested between 1 January and 30 June 2024. Data extracted from patient records included clinical, demographic and testing-related variables. Results: The study included 133 participants who underwent pharmacogenetic panel testing (mean age 32.2 years). The most common diagnoses were unipolar depression (35%) and psychosis (27%). On average, participants had tried 1.33 antidepressants and 1.29 antipsychotics before testing, with antipsychotics being the most used medication group at the time of testing. The main indications for testing were medication optimization, and poor response or adverse effects, however, the indication was not documented in 21% of referrals. The mean time from referral to result availability was 24.8 days and to analysis completion 59.8 days. Conclusions: Pharmacogenetic panel testing appears to be primarily targeted toward general medication optimization and difficult-to-treat psychiatric patients, although the clinical utilization and documentation of test results remain variable. The findings support the need for clearer clinical processes and standardized documentation practices to facilitate the integration of pharmacogenetics into psychiatric care.