Improving Outcomes Through Pharmacogenetic Testing

Pharmacogenetic testing is the most exciting area I have encountered in psychiatric practice since the advent of the SSRIs/SNRIs and the atypical antipsychotics. These tests provide data that truly offer concrete assistance in selecting a pharmacotherapy that is more likely to have both efficacy and tolerability for a particular patient. Until recently, I have been selecting treatment based on diagnosis subtype, past treatment history, family history, and a few clinical pearls related to presentation. In the 40 or so patients with whom I have now used genetic testing, all but 1 patient had significant variations that contributed to my choice of treatment or a change in treatment.

I first used this testing only in patients with treatment-resistant depression, but, after seeing the impact, I have begun to use it more widely. I see a role for pharmacogenetic testing in patients with psychiatric conditions other than depression, including patients who are treated with antipsychotics and stimulants. Our patients are so ill and their quality of life is so impaired that they would benefit from the use of every tool at our disposal.

My colleagues and I reported 2 cases in which we used genetic testing. Mr B, the second patient we described, was able to return to a very competitive university in a challenging course of study once his medications were adjusted and his severe side effects abated. Of course, he still faces challenges because his depression and his ADHD are both chronic disorders. However, he graduated with a bachelor’s degree and a master’s degree at the same time and now has a highly coveted job with a national firm. As his treatment continues, his genetic profile will play a part in any ongoing selection of pharmacotherapy.

I suspect that, without careful parental observation and the genetic testing, Mr B would have become further depressed over his perceived lack of competence in his academic pursuits despite his superior intellectual ability.

One of the most challenging issues in the field of genetic testing is the lack of payer support, and I have made significant efforts to educate our local public sector payers. However, a challenge with insurers often relates to short-term versus long-term gains in a sizeable population. Both treating psychiatrists and patients can provide advocacy to accelerate the acceptance of this valuable testing. Also, further data on clinical outcomes and population cost-savings can be provided by companies engaged in this technology.

In my practice, I have found that reviewing the results of pharmacogenetic testing is a wonderful psychotherapeutic intervention for the demoralized patient who has tried many psychiatric treatments without success. Renewed hope is particularly evident with young adults who, along with their parents, have not understood their lack of treatment response and viewed it as a failure to expend enough effort to get better. I have found that this broader understanding of the link between heredity and treatment response can be a turning point with some patients. Additionally, noting that the parents are the source of the genetic mutations elicits comments about the parents’ psychiatric status.

I look forward to significant advances in the field of pharmacogenetics and the benefits those advances will bring.

Financial disclosure:Dr Rhea is a consultant for United Behavioral Health and Amerigroup. ​