Pharmacogenomic Testing for Bipolar Disorder

What is Bipolar Disorder?

Bipolar Disorder (BP) is a mental health disorder that affects an individual’s moods causing them to have episodes or periods of extreme mood swings with symptoms of depression and/or mania.These mood swings can make it challenging for individuals to lead a normal life and perform everyday tasks. The three main types of bipolar disorder are: 

·   Bipolar I Disorder: Characterised by manic episodes which are severe, last for at least 7 days and require hospitalisation.

·   Bipolar II Disorder: Characterised by episodes of hypomania (a less severe form of mania) and typically does not require hospitalisation. 

·   Cyclothymic Disorder(Cyclothymia): Marked by periods of hypomania and periods of depressive symptoms that last for at least 2 years.

Common symptoms of BP include fatigue, loss of interest or pleasure, persistent sadness, unusually happy and euphoric, impulsivity, changes in appetite and sleeping patterns ,and suicidal thoughts.

Is Bipolar Disorder Hereditary?

Research shows that genetics play a major and significant role in the likelihood of an individual developing bipolar disorder. If a close relative such as a sibling or a parent has bipolar disorder, the chances are higher for an individual developing it compared to those who don’t have relatives with it. 

Although, there are other factors such as environmental factors including stress, trauma, significant life changes etc. that can contribute.

Benefits of Pharmacogenomic(PGx) Testing in Bipolar Disorder

There are certain benefits that are associated with Pharmacogenomic testing in BP such as having personalised medication choices, being able to make dose adjustments, avoiding potential adverse drug reactions that might arise and overall having improved treatment outcomes. This ultimately leads to patients having better adherence to prescriptions.

The PGx test results can help give the healthcare provider insight on dosage adjustments that might be required and this is based on how quickly or slowly a patient can metabolise certain medications ultimately reducing the risk of toxicity and treatment failure. 

With PGx testing, healthcare providers can bypass the traditional approaches of often trying different medications until finding one that works for the patient, which can take weeks and months. By identifying which medications are more likely to be effective for the patient based on their genetic profile, healthcare providers are able to reduce the trial-and-error process, ultimately saving time and costs.

Common Medications for Bipolar Disorder

Medications used in bipolar disorder treatment are characterised into:

1. Mood stabilisers include: Lithium, Valproate, Carbamazepine, Lamotrigine
   
   
2. Antipsychotics include: Olanzapine, Quetiapine, Risperidone, Aripiprazole, Lurasidone, Asenapine and Cariprazine
    
3. Antidepressants include: Fluoxetine, Sertraline and Bupropion

 

Using PGx to Help Treat Bipolar Disorder

Treating bipolar disorder can be complex due to the unique genetic makeup of each patient , which affects their response to medications. PGx can help treat BP by optimising medication selection , tailoring dosage levels, minimising the risk of adverse effects, managing antidepressant-induced mania, reducing the time it takes for a patient’s treatment response and individualising the patient’s treatment plan.

For example, Lithium is a common medication used in the treatment of bipolar disorder, however, not every patient responds well to it. PGx testing can assist in predicting whether the patient will benefit from taking it based on specific genetic markers such variants in the SLC6A and GADL1 gene which are associated in lithium response. PGx can also predict how different patients respond to antipsychotics (such as olanzapine, quentiapine) and antidepressants (selective serotonin reuptake inhibitors). The genes that can affect how these drugs are metabolised are variations in the CYP2D6 or CYP2C19.

What will the PGx Test results indicate? 

A PGx report categorises gene-drug interactions as:

• Mild: No dosage adjustments required.
• Moderate: Dosage adjustments may be necessary.
• Serious: An alternative drug is recommended due to the high risk of adverse drug reactions.

The Way Ahead

Pharmacogenomics can revolutionise the treatment of bipolar disorder by providing healthcare providers with insights on how a patient’s genetic makeup can influence the safety, metabolism and efficacy of the drug. Therefore leading to providing the patient with the best possible medications that will have the least risk of side effects , ultimately, enhancing the speed and success of the treatment and better treatment outcomes for the patient.

For more information on our PGx testing services and how they can benefit your practice, please request a quote.