Schizophrenia Daily News Blog

Epigenetic Changes Identified in Schizophrenia

In a new study announced this week scientists say that they have discovered epigenetic changes (that is, chemical changes to a gene that do not alter the DNA sequence) in individuals with schizophrenia and bipolar disorder. This is the first epigenome-wide investigation in psychiatric research, and this groundbreaking data may be a significant step on the journey to fully understanding major psychosis and also helping in identifying with greater knowledge how to prevent schizophrenia. Epigenetics is a fast-growing new area in medicine because some researchers now believe that our diet, the chemicals we are exposed to and even our behavior toward one another can cause changes in the way our genes are expressed, and contribute or trigger mental illnesses like schizophrenia and bipolar disorder - and some of the epigenetic changes may even be passed on to future generations.

In the past we've covered the research that has identified epigenetic changes that have been linked with increased risk of mental illness. For example, researchers have discovered that baby mice and rats - when they are not licked, groomed and soothed by their mother as much as other mice and rats - grow up to be much more fearful and anxiety prone (the rodent version of an anxiety disorder). Interestingly - research is suggesting similar results in humans (see this article on human child environment and depression). This is just one example of many possible epigenetic factors that may play a role in mental illness.

In essence, the epigenetic factors seem to be a way to explain how the "environment" part of the causal factors in schizophrenia are believed to interact with the "genetic" risk factors of schizophrenia - to ultimately trigger schizophrenia. The epigenetic factors seem to be anything from nutritional factors, to early psychological stress, or any of the other identified factors. One important fact to note is that it is impossible to tell retroactively what caused schizophrenia in a person as there are so many different environmental (biological and psychological) factors that have been identified as risk factors.

Studies have shown that the early positive environment of young mammals results in long term epigenetic changes that can help or hinder the animal throughout its life. In fact it is research like this that is suggesting how our psychological and social environment that we grow up in can have long term impact in our biological development. Some researchers believe that it is the epigenetic effects of prenatal (pre-birth) environmental factors like nutrition and stress that may be behind the increased risk for mental illness in some children .

Its also research like this that has resulted in new guidelines for childcare recommendations that suggest the mental health of the child is maximized when they are held by a caring, sensitive and responsive human being, and why doctors are recommending that babies be held at least 4 hours a day, and that sensitive, empathetic parenting is best for long term positive brain development and mental health.

In the new study announced this week Dr. Arturas Petronis, senior scientist in Canada's Krembil Family Epigenetic Laboratory at the Center for Addiction and Mental Health (CAMH), and his team studied 12,000 locations on the genome using an epigenomic profiling technology developed at CAMH. Approximately one in every two hundred of these genes showed an epigenetic difference in the brains of psychiatric patients. Significantly, these changes were noted on genes involved in neurotransmission (the exchange of chemical messages within the brain), brain development, and other processes linked to disease origins.

Dr. Petronis explains that these epigenetic changes may be the missing link in understanding what causes an illness. “The DNA sequence of genes for someone with an illness like schizophrenia and a for someone without a mental illness often look the same; there are no visible changes that explain the cause of a disease. But we now have tools that show us changes in the second code, the epigenetic code, which may give us some very important clues for uncovering the mysteries of major psychosis and other complex non-Mendelian illnesses.”

This proof-of-principle study is the first demonstration of what CAMH epigeneticists have hypothesized for the last 10 years. “Until now, we only had theories that epigenetic changes were important to understanding what causes major psychosis,” explains Dr. Petronis. “Now we have the tools and expertise to support our theories and we can look at conducting larger studies, which will hopefully give us an even better understanding of psychiatric illnesses. And once we understand the primary molecular causes of an illness, we can advance diagnosis and treatment approaches, and possibly even prevent illness.”

The Krembil Family Epigenetics Laboratory is the only psychiatric epigenetics laboratory in North America, one of the few programs in North America that is exploring this field.

Related Reading:

Childcare, Genetics, Epigenetics and Schizophrenia

Early Family Experience Can Eliminate the Effects of Genes, Minimize Risk of Mental Illness

Epigenetics and Mental Illness - Child Care Has an Impact

How Families Can Nurture Resilient Children

Nine Good articles on Epigenetics, from Major Newspapers and Magazines

How to Prevent Schizophrenia - Tactics for Risk Reduction

Children's Vulnerable Brains and Mental Health

Scientific Information: An Epigenetic Hypothesis for Schizophrenia Pathophysiology (Schizophrenia Research Forum)