Top Five Most Common Mental Disorders Linked By Genetic Variation
Understanding how and why teens develop mental disorders can lead to new approaches in prevention and treatment. As they grow from children into adulthood, teens undergo complicated physical, behavioral and mood changes. Add the risk of mental disorders to the mix and it can be confusing for parents to interpret everything.
Researchers from the Cross Disorders Group of the Psychiatric Genomics Consortium (PGC) have found a genetic link that furthers the understanding of how genetic variations overlap between common mental disorders. They have found that the five most common mental disorders have an overlap in their genetic risk factors. Their findings can help improve mental disorder treatment and assist scientists in developing more effective drugs to help teens manage disorders like attention deficit hyperactivity disorder (ADHD), autism, bipolar disorder, depression and schizophrenia.
In 2013, a large study involving over 800 scientists in 20 countries linked mental disorders with regions in chromosomes but did not disclose the exact genes that were shared by the disorders. This newer research by the PGC specifically studied single nucleotide polymorphisms (SNPs). While all humans share the same genes, there are variations and mutations that can form and change a person’s genetic make-up. SNPs are one of the variations in genes.
Researchers found the highest overlap of genes between bipolar disorder and schizophrenia at 15 percent. Between other mental disorders they found the following percentages of overlap:
- Bipolar disorder and depression – 10 percent
- Depression and schizophrenia – 9 percent
- Autism and schizophrenia – 3 percent.
Dr. Naomi Wray, co-leader of the study, emphasized that her team only analyzed the common gene variants between disorders. That means that the total number of genes that could overlap between disorders is likely much higher.
Parents who have suffered from mental disorders often watch their children for any similar signs of the disorders. Some adolescents have a higher risk of developing a mental disorder simply because of their family genes.
Some adolescents will develop mental disorders spontaneously, as in a mutation. Researchers analyzed the likelihood of a person having a genetic mutation that would increase their risk of developing a mental disorder. They used the SNP mutation to see how often it overlapped in patients with mental disorders. For all disorders, patients displayed more risk from genetic inheritance than mutation, but researchers were able to see how much those mutations also risked the disorder. In ADHD, 75 percent of patients displayed genes from heredity while 28 percent were from spontaneity. Others were as follows:
- Autism – 80 percent heredity, 14 percent spontaneity
- Bipolar Disorder – 75 percent heredity, 25 percent spontaneity
- Depression – 37 percent heredity, 21 percent spontaneity.
Dr. Thomas Lehner, chief of the National Institute of Mental Health, believes that this study leads toward a future finding treatment and prevention of mental disorders through genetic research. When a teen doesn’t want to go to school because someone may notice their hands shaking or their face twitching from anxiety or cannot find the mental energy to interact even with best friends, then mental illness has moved in with cruel control. Teens have enough pressures on them as they grow toward adulthood and mental illness is one more obstacle they have to face. Lehner believes this study brings a bit more hope in mental illness prevention and treatment.