You may have heard about genetic testing as the foundation of a new approach to medicine. It has been successfully applied to areas like cancer and cardiology treatment. But what about for mental health conditions?
The field of psychiatric genetics has made great strides in the past 20 years, particularly for illnesses such as schizophrenia and neurodevelopmental disorders. Read on to learn more how this impacts medicine for depression, anxiety, and bipolar disorder.
Understanding Genetic Testing for Mental Health
The main goals of genetic testing are to [1]:
- Help in understanding a patient’s diagnosis, either for a current or future illness, or that of one’s family.
- To inform clinicians of the presence, or future risk, of physical or mental illnesses and the need for monitoring.
- To predict response to possible treatment approaches and assist in choosing treatments with higher likelihood of success, or lower likelihood of harm.
The key here is to consider whether or not a test has usefulness and potential risks or harm, as well as advantages. And as with any medical investigation, before doing genetic testing it’s important to consider whether learning the results will have any influence on management of the condition or will helpfully predict the outcome.
Precision medicine, or personalized medicine as it’s also called, is the application of genetics for healthcare treatment. This innovative approach considers individual genetic differences, environments, and lifestyles. The objective is to customize healthcare interventions to the unique characteristics of each patient and thereby improve the effectiveness of treatments while reducing the risk of adverse effects.
Mental health conditions are complex, often involving a number of factors including:
- Genetic predisposition
- Environmental stressors
- Personal experiences such as trauma
- Chemical imbalances in the brain
Genetic testing technology is rapidly developing. Progress has been made over recent years in identifying genetic contributions to major psychiatric conditions. There are hundreds of individually rare—but collectively common—single gene or variants that can cause mental disorders.
And it’s not just genetics labs that offer genetic testing. Various kits are commercially available that you can buy directly, such as the well-known 23andMe. However, these kits have significant limitations and potential for harm when their results are incorrectly interpreted or misunderstood [1].
Advances in genetics research have added to our understanding that many mental health disorders have a number of causes or factors at play. The interaction of multiple genetic and environmental factors influences an individual’s risk of developing a mental health disorder, its progression, and potential treatment responses [1].
Autism spectrum disorder (ASD) and intellectual disability, collectively referred to as neurodevelopmental disorders, at present qualify as the only psychiatric disorders with enough evidence supporting genetic testing as part of standard clinical practice [2].
It’s especially important to be clear that psychiatric genetic testing, for the most part, cannot either confirm or rule out any psychiatric diagnosis [1].
Research shows that, as with almost all human traits, there is some genetic contribution to the susceptibility to develop mental illness. This is substantial for schizophrenia and bipolar disorder, but is smaller, although present, for conditions such as anxiety and depression. Genetic variation even has an effect on the likelihood for conditions like post-traumatic stress disorder which has a clear environmental cause.
Genetic Testing for Depression and Anxiety
Research suggests that depression and anxiety are heritable, meaning they can run in families. Mental health disorders are influenced by both genetic and environmental factors. So while a test may show an increased risk, it cannot definitively predict whether an individual will develop depression or anxiety.
But a recent groundbreaking study found that youth with a greater genetic predisposition to neuroticism—a personality trait linked to anxiety and mood problems—were more likely to develop major mental illness by the time they reached adulthood [3].
Nonetheless, several key factors must be considered:
- Polygenic risk scores: Such scores, which aggregate genetic variants associated with traits like neuroticism, can help estimate susceptibility to conditions like depression and anxiety. Nonetheless, these are not standalone predictors and are most effective when combined with family history and environmental factors [3].
- Biomarkers for anxiety: Studies have identified blood biomarkers that map to states of anxiety. This shows potential for predicting the severity and progression of illness. But they are still undergoing research and are not widely used clinically [4].
- Limitations: While genetic predisposition plays a role, environmental triggers such as stress or trauma often have a more significant effect on whether these conditions develop [1].
One research group with a major study on anxiety disorders expressed the hope that biomarkers for future risk of developing anxiety may be useful in preventive approaches before the full-blown disorder appears or reappears. These include social, psychological or biological interventions such as medications or nutraceutical supplements.
They emphasized the importance of this research work, given that [4]:
- 1 in 3 people will have a clinical anxiety disorder episode in their lifetime.
- Anxiety appears to be increasing in younger people.
- Anxiety can severely affect the quality of life, sometimes leading to substance use disorder and even suicide.
- Not all patients respond to current treatments.
Genetic Testing for Bipolar Disorder
Medication is successfully used in bipolar disorder to control episodes of mania and depression and to prevent relapse once the mood has stabilized. Once the doctor finds the right drugs and dose, it’s possible to manage symptoms effectively. However it’s not always easy to do so and without undesirable side-effects. Traditionally, a trial and error approach has been used to find the right drug or combination.
However, genetic testing is increasingly being used for this purpose. By identifying the person’s unique genetic markers, a lab can accurately predict which drugs are likely to be effective and which are not. Genetic testing can also be used to show the optimum dose to achieve the desired results without unwanted side effects [5].
One scientist reported it is well established that bipolar disorder has a substantial genetic basis and identifying DNA variations can provide insights into the condition’s underlying biology. Their study found DNA variations involved in brain cell communication and calcium signaling an increased risk of bipolar disorder [6].
Several key factors need to be considered:
- Genetic variants: Studies have identified numerous genetic regions associated with bipolar disorder.
- Heritability: Bipolar disorder is highly heritable, with genetics explaining up to 70% of cases. Nonetheless, genetic testing alone is not adequate for diagnosis and needs to be complemented with clinical assessments and family history.
Limitations of Genetic Testing for Mental Health
There are several existing limitations of genetic testing for mental illness, despite the great strides made and ongoing, including:
- Not diagnostic: Genetic testing cannot definitively predict mental illnesses and should be viewed as a supplementary tool. This is due to the complex interplay of genetic, environmental, and lifestyle factors. Genetic testing can indicate a higher risk, but cannot predict if you will have depression or anxiety.
- Potential for misinformation: It’s complicated to interpret genetic test results and there can always be the risk of misinterpreting them. It’s essential to consult with a genetic counselor or qualified healthcare provider who can explain what the results mean and how they can guide your mental health care.
- Cost and accessibility: Genetic testing can be costly and not all tests are covered by insurance. Availability of testing services can also vary depending on where you live.
- Emerging research: Ongoing efforts continue to refine genetic tests for better accuracy and clinical use in psychiatry.
.Improving Mental Health in Utah
Treatment is available in Utah. Are you or a loved one looking for a compassionate space to heal from trauma or PTSD, other mental health conditions, or addictions? Our licensed trauma-informed professional therapists and counselors at Corner Canyon Health Centers can provide compassionate help using a range of therapeutic and holistic techniques.
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Sources
[1] Royal College of Psychiatrists (2023). College Report CR237– The role of genetic testing in mental health settings.
[2] Pinzón-Espinosa, J., van der Horst, M., Zinkstok, J. et al. Barriers to genetic testing in clinical psychiatry and ways to overcome them: from clinicians’ attitudes to sociocultural differences between patients across the globe. Transl Psychiatry 12, 442 (2022)
[3] D’Entremont, Y. 2023. Genetic testing could help identify youth at risk of developing mental illness, Dal study finds. Halifax Examiner.
[4] Roseberry, K. et al. 2023. Towards precision medicine for anxiety disorders: objective assessment, risk prediction, pharmacogenomics, and repurposed drugs. Nature. Mol Psychiatry 28, 2894–2912 (2023).
[5] Bipolar Disorder. Myogenes.com
[6] Largest Genetic Study of Bipolar Disorder Identifies 64 Regions of the Genome That Increase Risk for the Condition. Mtsinai.org
