Ever since the discovery of the double helix structure of DNA in 1953, we’ve seen how picking apart the complex pattern of our genetics allows us to further understand our inner workings. It’s a window into the intrinsic design that shapes not only our physical fabric but our mental attributes as well.

Historically, we often viewed our mental health as being separate from our physical well-being, as if they were isolated parts of our existence. However, as our understanding of genetic science grows, we can see the ways in which our inherited traits are intertwined. As well as opening up new fields of exploration, these discoveries can help us make more accurate diagnoses and help us build towards a future that provides better support, insight, and empathy for those facing mental health challenges.

What Have Historical Studies Revealed About Genetics in Mental Health?

Since the mid-1980s, the understanding of the genetic basis of mental disorders has evolved, with family, twin, and adoption studies playing a pivotal role. These studies provided consistent evidence for the substantial role of genetic factors in the aetiology of mental illnesses, with heritability estimates for most psychiatric disorders found to be high, between 0.4 and 0.81.[1]

In the case of bipolar disorder, for example, family, twin, and adoption studies have helped define the genetic epidemiology of the condition, showing that first-degree relatives of affected people have an increased risk of developing the condition.[2]

Similarly, these types of studies provided significant evidence for the role of genetics in numerous psychiatric disorders, including obsessive-compulsive disorder, panic disorder, major depressive disorder, and schizophrenia, among others.[3] Specifically, US-based studies conducted from 1980 to 2015 have also reinforced the role of genetics in mental health, particularly in understanding the risk factors associated with bipolar disorder.[4]

How Do Environmental Factors Interact With Genetics in Mental Health?

While it’s recognised as a scientific fact that our genes can affect mental health, this doesn’t mean it’s an open-and-shut case. It’s a story of interaction, where many factors play significant roles in shaping our psychological landscape. The places we inhabit, our early childhood, social relationships, or even the daily stressors we encounter can influence our mental health.

In addition, research accentuates the synergy between genes and environmental influences. For instance, if we have a genetic predisposition to anxiety or depression, we may experience heightened symptoms in stressful or adverse environments. Our genes set the stage, but environmental factors often play a leading role.

Epigenetics – the study of how environmental factors can alter gene expression – has helped us understand this relationship further. Environmental stressors such as trauma or substance use can trigger epigenetic changes, potentially leading to mental health disorders. These changes, although not altering the DNA sequence, can affect how genes are expressed, thus contributing to the onset or exacerbation of mental health conditions.

Which Mental Health Disorders Are Linked Genetically?

Researchers have found several links between genetic predispositions and increased probability of mental health conditions. While these can indicate increased risk, we need to remember that the presence of these genes is not a definitive outcome – no one factor is a guarantee we’ll develop them.

Bipolar Disorder

Bipolar disorder affects 1.3 million people in the U.K. and is characterised by extreme mood swings that alternate between mania and depression. While research is ongoing, it’s apparent that bipolar disorder has familial ties, with higher risks among those with a first-degree relative diagnosed with the disorder. A 2014 study revealed a connection between single nucleotide polymorphisms (SNPs) and the development of bipolar disorder, indicating a notable genetic aspect, although more research is needed to understand this association fully.

Depression

Depression affects approximately 350 million people globally. It’s more than mere sadness; it involves severe feelings of hopelessness and agitation. Studies involving twins have shown a 37% rate of inheritance for depression, which indicates a substantial genetic component. Genes regulating neurotransmitters, particularly the serotonin transporter gene, are believed to play a role in depression, though the full genetic landscape is yet to be fully understood.

Anxiety

Anxiety disorders also have a genetic component. These disorders will affect about 20% of the population at some point in their lifetime, and studies on twins and close family members have revealed a genetic role at a rate of 30-50%. Genetic association studies have linked anxiety to certain genes, including 5-HTT, 5-HT1A, BDNF, and MAOA; however, the precise nature of these associations and their interaction with environmental factors is still being studied.[5]

Schizophrenia

Schizophrenia affects approximately 1% of the population and exhibits strong genetic links. Having a close family member with schizophrenia increases one’s risk from 1% to 10%, and if both parents have it, the risk increases to 50%. Current theories suggest that a microdeletion in chromosome 22 (22q11) may contribute to the development of schizophrenia, though the complete genetic picture is still being compiled.[6]

Eating Disorders

In anorexia, abnormalities in genetic factors regulating cholesterol production, body mass index, obesity, fasting insulin, and fasting glucose have been identified, describing it as a disease rooted in both mental health and metabolism. Similarly, bulimia and binge eating disorder exhibit genetic influences, with family and twin studies highlighting the hereditary nature of these disorders.[7]

Addiction

Research has shown that people with a family history of addiction are at a higher risk of developing addiction themselves. Various genes have been associated with an increased susceptibility to addiction, although the exact genetic mechanisms remain under investigation. The interplay between genetic predisposition and environmental triggers, such as stress or exposure to substances, significantly contributes to the onset and progression of addiction.[8]

What Are the Pitfalls of Genetic Self Testing for Mental Health Conditions?

Genetic testing has become more and more accessible in recent years; however, it’s not without its problems, and testing for mental health risks can be a double-edged sword. On the one hand, it offers insight into our genetic predisposition, but on the other, the results can be hard to interpret and without professional guidance, the data can be confusing and misleading.

There’s also a risk of overestimating the influence of identified variants. We already know mental health is a complex interplay of genetics, environment, and personal experience, so taking a test’s results as a surefire way of determining that we’re either safe or destined to have a condition could cause undue anxiety or false reassurance. Although many organisations are offering this service, it’s best to refer to advice from the National Institute of Mental Health, “no gene variant can predict with certainty that a person will develop a mental disorder.”[9]

Contact Us Today

While Assured Healthcare and Wellness doesn’t provide genetic testing, we offer something equally integral: compassionate community care led by nurses who are experienced in dealing with the unique challenges and nuances of mental health.

While we acknowledge that genetics can lay the foundation for mental health conditions, we also know the strength of support and care we provide can help shape a positive future. If you’re seeking caring and professional mental health support, contact us today, and let us help you step into a brighter, supported tomorrow.

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The Role of Genetics in Mental Health