By Sean P. Horan, DO, Pediatric Psychiatrist and David Mancuso, Executive Director Pharmacy and Laboratory Services
Depression and anxiety significantly affect many children and teens. For those struggling with these conditions, medication often serves as an effective treatment option. Typically, psychiatrists prescribe antidepressants after a thorough examination to exclude other medical or behavioral issues.
Many parents express concerns about starting their child on antidepressants, particularly regarding potential side effects and the medication's efficacy. In response to these concerns, there's a growing shift towards personalized therapy. This approach takes into account individual factors such as genetic makeup, which can influence how a patient metabolizes and responds to medication.
Pharmacogenetics
Pharmacogenetics (PGx) focuses on these genetic factors to predict drug efficacy and side effects, thereby improving outcomes by customizing treatments according to genetic profiles. Studies indicate that genetic differences can account for up to 30% of variability in treatment response.
Families considering antidepressants for their children can find support through the Pharmacogenomics Program at Nicklaus Children’s Hospital. This program offers genomic testing to pinpoint medications likely to produce the best clinical outcomes with the fewest side effects. It is accessible for patients with various diagnoses, including mood disorders, cancer, and blood conditions.
Genes Coding for Drug-Metabolizing Enzymes
The ability to identify optimal medication alternatives through pharmacogenomics represents a significant breakthrough for patients grappling with depression. Traditionally, some patients might need to try multiple antidepressants before finding one that works. Pharmacogenomics improves the chances of identifying a medication that’s more effective and/or has fewer side effects faster than ever before.
For example, genetic variations in enzymes such as CYP2D6, CYP2C9, CYP2C19, and CYP2B6 significantly impact drug metabolism and affect drug blood concentrations. This is crucial for psychotropic medications, with significant percentages metabolized by these enzymes. Antidepressants such as fluoxetine, fluvoxamine, and paroxetine primarily rely on CYP2D6, whereas citalopram and sertraline are metabolized by CYP2C19.
Categories of Antidepressants
Testing can determine which categories of antidepressants and specific products may be most effective:
- SSRIs (Selective Serotonin Reuptake Inhibitors): These medications enhance serotonin flow in the brain, helping regulate mood, sleep, and other functions.
- SNRIs (Serotonin and Norepinephrine Reuptake Inhibitors): This class promotes the flow of serotonin and norepinephrine, neurotransmitters that help regulate mood and anxiety.
- TCAs (Tricyclic Antidepressants): Among the first developed antidepressants, TCAs increase serotonin and norepinephrine in the brain but are less commonly prescribed today due to their side effects compared to SSRIs and SNRIs.
- NDRIs (Norepinephrine-dopamine reuptake inhibitors): For example, bupropion affects mood by increasing dopamine and norepinephrine levels and can be beneficial for those unresponsive to SSRIs.
Starting a Child on an Antidepressant
Given the substantial evidence supporting PGx-guided pharmacotherapy, it is highly recommended for psychiatric patients. After a comprehensive medical examination and reviewing PGx test results, the doctor will discuss potential side effects with the patient and family. This dialogue helps everyone involved recognize and report any concerning signs.
If the family agrees to proceed, the child will have follow-up appointments to monitor progress and assess the medication's effectiveness. Parental insights during treatment are invaluable for evaluating the impact of the antidepressants. Additionally, talk therapy may be prescribed or continued as part of achieving optimal results.
For more information about the Pharmacogenomics Program, please visit www.nicklauschildrens.org/pharmacogenomics.