Pharmacogenetic Testing to Reduce Depression and Anxiety in Adults Treated with Low-Dose Lithium

Abstract

Mental illnesses, including major depressive disorder, bipolar disorder, and generalized anxiety disorder, are leading causes of disability in the United States, affecting about one-third of Americans and one-fifth of Kansas City residents. A substantial number of patients with bipolar disorder are misdiagnosed with major depression. Clinical evidence supports the use of both pharmacogenetics and lithium for treating mood disorders and anxiety. This research aimed to determine whether lithium effectively decreases depression and anxiety in adults with a risk allele on CACNA1C genotypes. The study design was correlational. Fifty patients were treated at a nurse practitioner-owned clinic specializing in psychiatric services in Prairie Village, Kansas. Chart review was used to assess pharmacogenetics in guiding treatment with lithium therapy for depression and anxiety. Adults over 18 diagnosed with major depressive disorder, bipolar disorder, or generalized anxiety disorder presenting with an abnormality in the CACNA1C gene single-nucleotide polymorphism rs1006737 were included in this research. Patients were assessed by a nurse practitioner using the PHQ-9 for depression and GAD-7 for anxiety before and after treatment with low-dose lithium (≤ 600 mg/d). There was a significant reduction in depression and anxiety for all CACNA1C genotypes. Pharmacogenetic-guided treatment is an emerging field. This study could aid in establishing genetic testing as an effective clinical tool for treating depression and anxiety using lithium, an inexpensive and widely available medication.