Researchers have now published a sizeable number of reviews of studies that show a link between emotional states and genes. They have examined the correlations between emotional disturbances—such as schizophrenia, depression, panic, and post-traumatic stress disorder (PTSD)—and gene expression, especially in the brain.
They have come up with startling and compelling evidence that the patterns of gene expression in the brains of these unhappy sufferers are different from those of happier people.
Emotions, it turns out, are epigenetic, and can methylate genes in parts of our brain involved in the stress response.
The scientific world is having to rethink its priorities as it discovers that invisible human emotions have profound epigenetic effects. —Dawson Church
The process is not a one-way street, with emotions turning genes on and off. People with certain genes are more prone to unhappy emotions, though the evidence suggests that most conditions require external epigenetic triggers to stimulate these genes.
A 2008 study funded by the National Institute of Mental Health found there are genes that predispose a person to PTSD as an adult. But PTSD is much more likely to occur in these adults if they also have a history of abuse as children.
It’s an external environmental event, in the form of a traumatic childhood that provides the epigenetic stimulus to the inner environment that triggers the gene changes.
Such studies, using the new technology of DNA microarrays, or gene chips, are allowing scientists to peer into the gene expression in the fight-or-flight structures of the brain and find out how genes are different in people with various flavors of unhappiness.
One study compared the gene expression of medical students to their anxiety scores on a standard psychological test. A measurement of their gene expression was taken just before their licensing examinations, a time of high-test anxiety for the students.
It was compared with a second gene chip sample and psychological test taken nine months earlier to provide a baseline. The researchers found that during the high-stress period, 24 genes were expressed differently. The expression of stress genes tracked the students’ scores on the psychological test.
Another set of researchers looked at people who were lonely and depressed and compared the expression of their entire genome with a happier group. They found 209 genes that were differently expressed in the unhappy people. The nature of the affected genes is particularly interesting.
They code for, amongst other things, markers of our levels of immunity from disease. So unhappy people had weakened immune systems and were more susceptible to illness.
A research team found that depression and elevated cortisol correlate with changes in the expression of many of the genes in the limbic system of the brain, which is central to our stress response.
Another group examined the link between a gene that codes for cortisol and other aspects of the fight-or-flight response and the psychological trait of anxiety.
Anxious children were more likely to have this gene strongly expressed; the children of parents who had panic disorder, a very high degree of anxiety, showed an even stronger association between behavior and gene expression.
To translate what the researchers are saying into plain English (a language carefully avoided in scientific papers), the crazier and unhappier your family is, the more likely it is that you will be anxious and unhappy yourself, with the gene modifications to prove it.
Your Brain on Unhappiness
Not only do your genes change with unhappiness, your brain wiring changes, too.
Jeffrey Schwartz, a neuroscientist at the University of California at Los Angeles, has studied a psychological illness called obsessive-compulsive disorder (OCD). He’s tracked the changes that occur in bundles of neurons in the brain when OCD is treated.
Successful treatment results, literally, in a rewiring of the neural connections inside the brain. Like a house that adds wiring to the electrical connections that are used most frequently, and strips wiring away from neglected circuits, the plastic brain is in constant motion, responding to stimuli by creating new neural pathways.
Unhappiness reinforces our unhappy brain wiring and vice versa.
Science is catching up to where spirituality has been for thousands of years; the Buddha urged us to maintain a calm state of desireless attention to the present moment, reminding us, “We are what we think. All that we are arises with our thoughts. With our thoughts, we make the world.”
It’s interesting to notice that these epigenetic signals were provided by a wide variety of unhappy psychological conditions. Test anxiety is different from loneliness, which is different from PTSD, which is different from schizophrenia, which is different from OCD.
Yet the body seems to interpret them all as similar epigenetic stress signals.
Psychology has made an art of identifying and differentiating psychological conditions. The American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), notes hundreds of classifications of distinct emotional maladies, from “vascular dementia with delirium” (290.41) to “factitious disorder with predominantly psychological signs and symptoms” (300.16).
Although reductionism, the act of differentiating mental disorders into so many categories, has its uses, it’s worth remembering that the body doesn’t work that way. Whereas all these flavors of stressed-out unhappiness may look different to a psychologist analyzing the mind, they look biochemically similar to a biologist analyzing the body.
The Benefits of Reducing Stress
A Harvard physician became famous for asking the logical next question, “How can we reverse stress?”
Herbert Benson developed a method called the Relaxation Response. This stress antidote has practitioners sit quietly for t20 minutes, filling their minds with a positive phrase or belief, and focusing on relaxing their muscles from the feet all the way up to the head.
Studies showed that the Relaxation Response was able to help with many different ailments, from high blood pressure to infertility to rheumatoid arthritis to pain.
“How could a single, simple, stress-reduction technique affect so many different conditions?” researchers wondered. The answer had to wait until the invention of DNA microarrays at the end of the 20th century, which made possible the study of the Relaxation Response as an epigenetic intervention.
Benson took healthy subjects and compared the differences in gene expression patterns between long-term practitioners of the Relaxation Response and nonpractitioners. Then, he put the nonpractitioners through an eight-week training and found that their gene expression profile had changed to substantially resemble that of the long-term practitioners.
He then replicated his findings before publishing them. Among the genes that changed were those involved with inflammation, the rate at which cells regenerate, and the scavenging of free radicals, which are a prime contributor to aging.
“For hundreds of years Western medicine has looked at mind and body as totally separate entities, to the point where saying something ‘is all in your head’ implied that it was imaginary,” said Benson of the study. “Now we’ve found how changing the activity of the mind can alter the way basic genetic instructions are implemented.”
The Benson study’s coauthor says, “This is the first comprehensive study of how the mind can affect gene expression, linking what has been looked on as a soft science with the hard science of genomics.”
Psychology and spirituality have been regarded as less rigorous than biology and physiology, and the scientific world is having to rethink its priorities as it discovers that invisible human emotions have profound epigenetic effects.
