Depression could be caused by genetics. According to the EurekaAlert release, “The researchers examined the functional relevance of the genetic association between SLC6A15 and major depression. Already nondepressed subjects carrying the risk-conferring genetic variants showed lower expression of SLC6A15 in the hippocampus, a brain region implicated in major depression.” This is not the first time science has suggested genetics may play a role in depression.
Last year, a study published in Biological Psychiatry identified a set of blood markers believed to be the “genetic signature” of major depressive disorder (MDD). The results showed a set of seven gene products present in the blood of MDD patients, but not in healthy patients. To verify their results, the researchers used blood from the remaining subjects – 12 with MDD and 13 healthy – to run the test with a more commonly used and less expensive DNA amplification method called polymerase chain reaction (PCR). Once again, they found the same seven markers in the MDD patients and not in the healthy ones. The researchers are therefore confident that they found a set of detectable markers that can be used as a simple blood test to confirm a diagnosis of hereditary MDD.
How Scientists Read Genes
All genes result in the production of molecules — such as RNA and proteins – that can usually be detected in the blood. RNA molecules are direct transcriptions of the DNA messages contained in genes, kind of like photocopying a page from a book. This knowledge has lead scientists to suspect that they can develop blood tests to detect the presence of most hereditary disorders, including depression.
Genetic Studies Could Help Develop Blood Tests
Indeed, unlike other illnesses like diabetes and heart disease, there are no blood tests to determine if a patient definitively has depression or many other mental illnesses. The diagnosis of psychological disorders is frequently complicated by the fact that symptoms are often self-reported by patients, and therefore are highly subjective. This can lead to misdiagnoses when patients misunderstand or are uncomfortable revealing the true nature of their symptoms.
Other Recent Genetic Discoveries
OCD Researchers studying mutant genes in mice have found a link that someday could help people suffering from compulsive disorders such as trichotillomania, an obsessive disorder that leads to compulsive hair pulling. A team from the University of Utah School of Medicine discovered that mice with mutations in the Hoxb8 gene groomed themselves twice as much as other mice, causing hair loss and open skin lesions. The gene can be found in microglia, which is a type of immune cell that originates in bone marrow and migrates to the brain. To test their theory, the researchers performed bone marrow transplants on the over-grooming mice. Once the new microglia reached their brains, they displayed normal, noncompulsive grooming behavior. The researchers’ line of reasoning follows other research into microglia and immune system breakdowns that lead to the onset of an obsessive compulsive disorder (OCD). The findings, however, could prove to be a valuable tool for neurobiological studies of OCD and shed more light on the roles of different microglia in the brain.
ADHD The common symptoms of ADHD include hyperactivity, the inability to focus, and clumsiness or carelessness. For kids with ADHD, it can be a real struggle to stay seated during class, finish homework, and stay focused on a task. The problem for parents, teachers and the medical community is that currently the tests for ADHD are subjective, which can lead to over-diagnosis or a misdiagnosis. We may be getting a few scientific steps closer to proving ADHD is a genetic condition. New research coming out of Cardiff University in Wales is suggesting that chromosomal defects are responsible for ADHD. The study also suggests that those subjects presenting with a mental disability like autism or schizophrenia were twice as likely to also have ADHD.
Liberal Politics Yes indeed, new research suggests that a person’s political beliefs may be in part genetic. In a new study, scientists have pinpointed a gene that they suspect is partially responsible for people developing into liberals. The key word is partially. Of the people in the study who were liberal leaning, many of them had a similar gene variant — DRD4. In fact, DRD4 is referred to as the “thrill-seeking” gene. Gambling, extreme extroversion, sexual promiscuity and other adventurous human traits have also been blamed on DRD4 expression. Indeed, the research showed that DRD4 expression alone is not enough to make someone a Democrat, as much as that may have made a good headline when this research was first released. No, rather it was a combination of DRD4 expression and varied socialization.