What are the causes of mental illness? Are they environmental, genetic, or both? Genetic connections with mental illness are the subject of great study today and nearly every major mental illness has been identified with a gene(s). This would include anxiety, depression, ADHD, bipolar disorder, and schizophrenia. See the Article List under the Mental Health Articles tab of this website to read some of these studies about the genetic connections of mental illness. A genetic predisposition to a particular mental illness does not entail a certain prognosis, I hear this question and concern quite often. Just because one is genetically predisposed to depression or another mental illness, one may still avoid the manifestation of the illness in their life. This would be accomplished by avoiding the environmental factors (stressors) that would bring about this illness and also by eating a healthy diet, exercising regularly, and keeping a positive attitude. If you have depression in your family, it is best to acknowledge the genetics involved, and take precautions to avoid a depressive episode. Keep a cautiously optimistic attitude that you will live free of depression or another mental illness. Again a family history of mental illness increases the risk but does not entail with certainty that you will develop a mental illness. Some studies have even demonstrated that it is possible to prevent schizophrenia if one avoids the psycho-social stress, cannabis use, and other environmental and dietary issues that might be responsible for the manifestation of this illness. There are currently no bio-markets for mental illness as of 2012, yet even it there were, they wouldn’t reveal any more than a psychiatric evaluation. If mental illness should become curable in the future through genetic engineering or some other means, then these bio-markers will be more beneficial.
The study of the genetic connection with mental illness has given rise to a field of study known as epigenetics. I personally believe that environment and genetics are inextricably linked together with regards to the causes of mental illness. There has been much debate between those who believe that mental illness is grounded in genetics and those that believe that it is grounded in environmental issues. Ultimately the cause of mental illness is the body’s inability to produce or regulate the neuro-transmitters or chemical in the brain, these irregularities are caused for a variety of reasons. Some are directly caused by genetics, some are directly caused by environmental factors, and some are indirectly caused by environmental factors. Mental illness is no different than any other physiological or bodily illness; in the case of mental illness, the organ that is not functioning is the brain. In the case with diabetes, the organ not functioning is the pancreas. I hope this understanding helps in destigmatizing mental illness because nearly 50% of those with mental illnesses will postpone treatment for up to 11 years due to the stigma attached to these disorders.
The Genetics of Mental Illness: DNA vs Environmental Factors, or Both?
What impact does the environment have on genetics? The following article: Is Anxiety Genetic; highlights an interesting study conducted by Klaus Hansen of the University of Copenhagen. This study demonstrates the influence of stress on the developing fetus and how stress can “turn on” gene settings which can lead to anxiety. This particular study by Hansen suggests that the environment can change the DNA and leave someone with a genetic predisposition for an anxiety disorder later in life. Read the study
I believe that it is cogent to conclude that if environmental stress on a fetus can create a propensity for an anxiety disorder by affecting genetic switches, then young persons with developing brains, and even individuals subjected to horrific trauma can also undergo these genetic changes. This would also give us an answer to how these mental disorders enter our familial gene pools as well with regards to genetic mental illnesses.
The Genes Responsible for Mental Illness Had to Enter The Gene Pool at Some Point in Time By External Causes
How does mental illness enter the familial gene-pool? To say that a mental illness is genetic is quite vacuous because somewhere in the family of origin; this disorder must have entered from outside the family. Now the question of whether the initial cause was a gene mutation or environmental issue cannot be avoided. This also entails another issue viz. if mental illness is initially introduced to a particular gene-pool by means other than DNA, then of logical necessity… mental illness can still (today) be caused by factors other than DNA such as the environment. The question then becomes; what are some of the possible causes of mental illness? Are they biological, genetic mutations, environmental stressors, toxins, or merely passed along to us from our ancestors?
Studies have demonstrated different ways by which the environmental stress impacts on the genes of a fetus, how genetic mutations can be linked with depression, how a lack of vitamin D can be linked to schizophrenia, how missing proteins in the DNA are linked to depression, the possible discovery of a genetic link to suicide, how missing pieces of DNA are being linked to ADHD; and a new study showing a possible link with bipolar disorder and genetics. All of these studies offer prolific explanations regarding the origins of mental illness and the how they may enter a gene-pool.
Studies in Genetics and Medical Technology Are Making Great Strides in Isolating Causes and Treating Mental Illness Which May Lead to Genetically Engineering a Cure in the Future – Research Highlights
Research shows that stress can turn on genetic switches during fetal development which can cause a predisposition to anxiety. “We found that stress-activating factors can control our genes by turning on certain genes that were supposed to be silenced. It is very important that some genes are on and others are off in order to ensure normal fetal development and correct function of our cells later in life,” says Dr. Klaus Hansen, lead study author. The researchers pinpointed that methyl groups needed to be attached to various proteins in order for DNA to have proper gene settings. In common language, the B vitamins, especially folic acid, B12, and B6 are needed to ensure an adequate supply of methyl groups in the presence of stress. If a pregnant mother is lacking certain B vitamins, and thus methyl groups, this deficiency can cause a chemical reaction and deleterious gene settings to establish themselves. While little stress is best during pregnancy, stress can be offset to some degree with the adequate intake of B vitamins, which would appear to be quite protective for the developing fetus.
Another study on genetic mental illnesses from McGill University shows that a lack of a mother’s affection following birth caused the offspring to have DNA that was altered in that GABA was lacking. GABA is needed to relax the nerves. An inability to make GABA, creates a disposition for insomnia, anxiety, and in more advanced cases severe mental illness (such as schizophrenia). GABA serves as the principle inhibitory neurotransmitter in the brain. Once again, the lack of affection in a critical time period shortly following birth can induce gene-related methylation problems. Here again a case of environment again playing a role on the development of our genetics and brain chemistry. This study also supports the idea that a mother needs adequate nutrition to manage mood during and after pregnancy in a way that supports positive emotions which in turn fortify the correct settings for genes. Setting gene switches, is a field of research known as epigenetics, which has a significant influence on future health concerns as these genes are not easily reset later in life to a healthy status. While improvements can be made later on, it takes a lot of work. It is much better to get the genes set properly in the first place, which places a whole new emphasis on the need for healthy pregnancy and a stable and loving environment for both mother and child. The future well being of everyone depends on it. This is the new era of mind-body medicine, linking directly to the emerging field of mind-social medicine.
The issue of the environment affecting cellular structure, neurotransmitters, and DNA is nothing new to science. We see this taking place in carcinogenic substances altering the genetic code thus causing cancer; we see the environment (e.g. substance abuse) altering the neuro-transmitters thus precluding the brain’s ability to produce the proper balance of dopamine, serotonin, and norepinephrine; however these studies in epigenetics are now taking this to a new level. Read about trans fats in our diets being responsible for depression, vitamin D may be a link to schizophrenia; and an article about missing pieces of DNA being linked to ADHD.
As epigenetics progresses, so will our understanding of the primitive causes of mental illness, with the hope that this knowledge will bring about better treatments and maybe a cure someday. Are you seeking an experienced Scottsdale psychiatrist? Please contact my office if you would like to set an appointment. I treat anxiety, depression, OCD, ADHD, bipolar disorder, panic attacks, PTSD, and schizophrenia. I have been a psychiatrist in Scottsdale since 2001 and formerly practiced in Phoenix in 1997.