Genetics and Mental Health
Genetics may play a significant role in shaping our, mental health and the risk of specific psychiatric disorders.
You can think of the brain as a computer. The brain circuitry (neurons, and their connections) is equivalent to the hardware. But we also have the human equivalent of software i.e. the processing of data that constantly bombards the brain through the 5 senses as well as the 6th sense (autonomic nervous system feedback). The software programming is done during the development of the foetus, its birth, and the developmental stages of the child.
All software can have “bugs” or errors of programming that are not obvious most of the time, allowing the application to function as required. However, a certain combination of data input can results in activation of the bug with consequent malfunctioning of the application. Similarly, the genetic and developmental programming of the brain can come with inherent “bugs”. Thus one programmed with a predisposition for mental disorder, but may go through life with perfect mental health as long as they do not encounter the right (or wrong) combination of events. However, when a combination of triggering factors is encountered the genetic “bug” may be activated and mental disorder precipapted. This is the emerging field of epigenetics.
Epigenetics examines the ways by which environmental factors turn genes on (expression) or off (non-expression) depending on environmental inputs. Environmental inputs include both internal, i.e. from the body, and external, i.e, from the surrounds. These epigenetic tags don’t just affect individuals during their lifetime, but can be passed from generation to generation. Research suggests genetics influence many personality traits including emotional stability, social and physical activity and constraint. Variations in a specific gene (RGS2) have been linked with personality traits, specifically those relating to anxiety.
A word of caution about genetic testing for mental disorders
Genetic factor identification makes it possible to develop tests for susceptibility to mental disorders diseases. A specific protein (GS alpha protein) localized to specific genes differs between those attempting suicide due to depression, and individuals without any overt psychological disorder. Treatment with anti-depressants restores normal localization of the protein; Thus GS alpha could serve as a biomarker for depression and for monitoring the effectiveness of anti-depressants.
Genetic research may therefore provide new tools to identify psychiatric diseases or monitor the efficacy of treatment and and tailor-make treatment for individuals.
Psychiatric disorders are complex diseases influenced by the interplay of many different genetic and environmental factors. Even though they seem to have significant genetic contributions, testing to identify the presence of a particular genetic variant that has been associated with a given psychiatric disease does not necessarily provide reliable or indeed useful information about an individual’s susceptibility towards that disease.
Hundreds of genes play a role in normal development and function of the brain, and different combination in these variations might lead to multiple different outcomes. Thus each individual with the same psychiatric disorder might have different genetic contributions to the development of that disease. Therefore testing for specific genetic variants may not have any usefulness in terms of predicting psychiatric disease risk.