Using a pharmacogenomic algorithm to guide the treatment of depression

Abstract

The objective of this study was to evaluate the potential benefit of utilizing a pharmacogenomic testing report to guide the selection and dosing of psychotropic medications in an outpatient psychiatric practice. The non-randomized, open label, prospective cohort study was conducted from September 2009 to July 2010. In the first cohort, depressed patients were treated without the benefit of pharmacogenomic testing (the unguided group). A DNA sample was obtained from patients in the unguided group, but the results were not shared with either the physicians or patients until the end of the 8-week study period. In the second cohort (the guided group), testing results were provided at the beginning of the 8-week treatment period. Depression ratings were collected at baseline and after 2 weeks, 4 weeks and 8 weeks of treatment using the Quick Inventory of Depressive Symptomatology, Clinician Rated (QIDS-C16) and the 17-item Hamilton Rating Scale for Depression (HAM-D17). Clinician and patient satisfaction was also assessed. The reduction in depressive symptoms achieved within the guided treatment group was greater than the reduction of depressive symptoms in the unguided treatment group using either the QIDS-C16 (P=0.002) or HAM-D17 (P=0.04). We concluded that a rapidly available pharmacogenomic interpretive report provided clinical guidance that was associated with improved clinical outcomes for depressed patients treated in an outpatient psychiatric clinic setting.

Pharmacogenetics of Antipsychotics

“…These include the assessment of drug metabolizer status and inclusion of other pharmacodynamics genes with promising findings showing superiority to treatment as usual. 176 Those tests are still relatively expensive and need to be improved by adding more gene variants. They also need to be implemented in ways that allow their use in clinical routine (that is, rapid processing and convenient costs), and physicians need to learn how to use their results in their practice.…”

Clinical Utility of Combinatorial Pharmacogenomics-Guided Antidepressant Therapy: Evidence from Three Clinical Studies

“…Based on the composite phenotype measured for each patient, the GeneSight test generates a report that provides prescribing options for 99% of all FDA-approved antidepressant and antipsychotic drugs used to treat depression. The test has predicted health care utilizations [10] and antidepressant outcomes [11,12,13] of patients with major depressive disorder, and does so with a precision that exceeds traditional pharmacogenomic associations based on single allelic variants [14]. …”

The Limitations of Genetic Testing in Psychiatry

“…An 8-week open study of 44 patients assigned in a nonrandom manner to treatment guided by the composite report (guided treatment) or nonguided treatment by the same clinicians, who were involved with the product, reported that patients in the guided group were less likely to receive medications in the ‘use with caution and with more frequent monitoring' category, presumably because of reluctance by the guided clinicians to prescribe medications that required more monitoring [47]. Although improvement of depression was similar for the first 4 weeks in both groups, a single measure at 8 weeks indicated increased depression scores for the nonguided but not the guided group.…”