As a genetic counselor who specializes in psychiatric illnesses and addictions, I frequently hear this question from the individuals and families I meet with: Is there a gene that's responsible for my condition? It's also a common question in online searches; depression, alcoholism and schizophrenia are among the top 10 topics that come up in Google searches that ask: “Is there a gene for. . .”
To fully answer these questions, it's important to provide a bit of background about what research has taught us about the causes of mental health-related conditions.
What Causes Problems like Psychiatric Illnesses and Addictions?
People have long wondered whether psychiatric problems and addictions are caused by “nature or nurture” – that is, whether it was genetic factors or our experiences that led to a condition. What we've learned is that both nature and nurture are important. Usually, problems like psychiatric illnesses and addictions arise as a result of the combined effects of genetic factors and our experiences!
There are lots of different genetic factors that can make people more vulnerable to developing psychiatric illness and addictions. And, to complicate matters, the genetic factors involved can vary from person to person.
Is There a Gene for Depression/Alcoholism/Schizophrenia?
When people ask this question, they are usually asking whether the condition in question can be entirely attributed to a single gene. For example, is there one depression or schizophrenia gene, or one gene that destines me to develop alcoholism? The simple answer is “no.” None of these conditions - or any psychiatric illness or addiction - can be entirely attributed to the presence of a single gene.
There are many different genetic factors that can increase a person's vulnerability to a psychiatric illness or addiction, but individually, most of them play only a very small role. Genes alone do not cause psychiatric illnesses and addictions. Experiences also play a role.
But I Would Really like Genetic Testing for Depression/Alcoholism/Schizophrenia…. What Can I Do?
From my experience as a genetic counselor, it seems that for many people questions about whether there is a gene for one of these illnesses often stem from fear of developing the same condition a family member has struggled with. For people who have already experienced psychiatric illness or addictions, these questions are often rooted in the idea that a genetic test might legitimize the illness, and perhaps decrease feelings of responsibility or perceptions of blame from others. Still others may worry about passing their condition on to their children.
These are very real and important concerns, and even though there may be no genetic testing that makes sense in your specific circumstance, a genetic counselor can help you understand your family history and what we know from research about the genetics of the specific condition that is of concern to you, and can work with you to figure out steps you can take to protect your mental health. To find out more about this, see my other blog posts. This article describes exactly how a genetic counselor could help you, and this article lays out what to expect and how to prepare for a genetic counseling session.
If you would like to speak with a genetic counselor about your own experience with psychiatric illness or addictions, or that of a loved one, you can connect with a genetic counselor in your area using NSGC's “ Find a Genetic Counselor ” tool.
Jehannine Austin , Ph.D., CGC is president-elect of the National Society of Genetic Counselors and is an associate professor in the Departments of Psychiatry and Medical Genetics at the University of British Columbia in Vancouver.