Genetic Sequence for Depression
Sun, April 18, 2021

Genetic Sequence for Depression

Mental disorders such as major depressive disorder, generalized anxiety disorder, and schizophrenia are known to be caused by a certain genetic sequence that makes a particular individual predisposed or prone to developing one or more of these illnesses / Photo by: andriano via 123RF

 

Mental disorders such as major depressive disorder, generalized anxiety disorder, and schizophrenia are known to be caused by a certain genetic sequence that makes a particular individual predisposed or prone to developing one or more of these illnesses. Major depression is one of the most common of them with at least 10% of the people in the United States reportedly having experienced symptoms of major depression at some point in their lives. 

According to Stanford Medicine, genes play an important role in causing depression. Scientists have looked at patterns of illness in families to estimate the heritability -- which is apparently common for major depression in which heritability is about 40-50%. This could mean that there is a possibility that the major cause for this specific mental illness can be 50% genetic. 


Psychiatric Disorders Come From Common Genes

The largest study that identified more than 100 gene variants that affect the risk of having a mental condition was done by the Massachusetts General Hospital. The researchers claim that many psychiatric diseases share a common genetic structure, as they stated in their recent study that was presented in the Psychiatric Genomics Consortium and was published in the journal Cell. 

According to Dr. Jordan Smoller, the senior author of the study, the director of MGH’s Psychiatric and Neurodevelopmental Genetics Unit and a professor of psychiatry at Harvard Medical School, identifying gene variants that can influence the person’s risk for having a mental condition is a critical step in improving the diagnosis and treatment for mental disorders. It is important to understand how specific genetic variations can contribute to the different kinds of mental conditions that can tell researchers and scientists something about the degree to which these disorders may share similar biology. 

The team had to identify multi-purpose gene variants by using a technique called genome-wide association to analyze genetic data from 494,162 healthy control participants and 232,964 people who were diagnosed with at least one common psychiatric disorder. Then the analysis identified 109 gene variants that affect the risk for more than one psychiatric disorder. The researchers were able to divide the conditions into three groups of genetically-related conditions because some psychiatric disorders have shared many gene variants.

The researchers claim that many psychiatric diseases share a common genetic structure, as they stated in their recent study that was presented in the Psychiatric Genomics Consortium and was published in the journal Cell / Photo by: Katarzyna Białasiewicz via 123RF

 

The first group involved compulsive behaviors that include anorexia nervosa, obsessive-compulsive disorder, and Tourette syndrome. The second group is made up of mood and psychotic disorders such as bipolar disorder, major depressive disorder, and schizophrenia. The last group is made up of early on-set neurodevelopmental disorders such as autism spectrum disorder, ADHD, and Tourette syndrome. Moreover, the researchers also found out that genes linked with multiple disorders show increased expression at the start of the second trimester of pregnancy and appear to be a critical component in the development of the child’s brain inside the womb. 

Dr. Phil Lee, the lead author of the study and a computational geneticist at the Center for Genomic Medicine at the Harvard Medical School, explained that knowing which kind of gene variant can increase the odds for developing multiple psychiatric disorders can provide new clues about the biological pathways that can contribute to the development of mental illnesses. It is crucial to learn how different kinds of disorders are related at a biological level since it can inform us how to classify and diagnose mental health conditions and it can also allow us to find the most optimal way to treat it. 

Furthermore, the research team also identified several gene variants that can influence the risk of a person developing a number of psychiatric disorders -- this is important to understand in order to find the proper prevention and care for psychiatric patients. These shared genes can be potential targets for developing new treatments that can benefit multiple kinds of psychiatric disorders, as reported on Science Daily, a psychology and neuroscience academic news website. 

How Depression Is Currently Treated

Depression is considered to be one of the most treatable of mental disorders and about 80% of the people with depression have responded well to treatment, with almost all patients gaining some type of relief from their depressive symptoms. Before being diagnosed, a doctor will do a thorough evaluation of the patient and might also get a blood test in order to make sure that the depression is not due to a thyroid problem or any other physical illness. 

Usually, people use medication such as antidepressants to treat or regulate the mood of the patient. The different brain chemistry of each patient will contribute to the individual’s depression and may factor into their treatment. Antidepressants might be prescribed to help modify one’s brain chemistry. Moreover, antidepressants may produce some improvement of mood within the first week but full benefits will only be seen after two to three months. 

Moreover, psychotherapy or talk therapy is also used for treatment and it is often used along with medication. Cognitive-behavioral therapy (CBT) has been found highly effective in treating depression. It helps a person recognize distorted and harmful thinking and also identify unhealthy coping mechanisms, and then change their behavior and thinking. 

With this recent development in genetic research, psychiatrists and researchers can identify better ways to treat a patient, specifically through their genetic makeup, and to prevent more severe cases.