Aim: We sought to explore how early adopters use pharmacogenomic (PGx) testing for treating depression and attention-deficit/hyperactivity disorder. Patients & methods: Prescribers of the Informed PGx (Progenity, Inc., Ann Arbor, MI 48108, USA) test completed a phone survey assessing use of PGx testing for different scenarios. We conducted a qualitative thematic text analysis of transcribed audio recordings of open-ended responses (n = 62). Results: PGx testing was used when treating multiple comorbidities or resistant disease, and to ease patients’ concerns with future therapy. Use of PGx testing is influenced by insurance coverage, interpretability of results and results turnaround time. Conclusion: Prescribers used PGx tests to modify medications for complex patients with depression, attention-deficit/hyperactivity disorder and other disorders to alleviate concerns related to adverse effects and lack of effectiveness.