Will I inherit a mental illness?

You might be aware that many medical conditions such as coronary heart disease, diabetes and hypertension are hereditary. Similarly, if someone in your family has a mental illness, you may wonder if you will inherit it. If you or your spouse is getting treated for a mental illness, you may be worried about your children inheriting the illness.

Although mental illness can run in families, research evidence indicates that most people with mental illnesses do not have relatives with a mental illness.

“Genetic studies show that it is not just a single gene that puts someone at the risk of a mental illness. It is a combination of genes on different chromosomes that increase the tendency to inherit a mental illness. One can draw parallels to the risk of inheriting diabetes, hypertension or cardiovascular disease,” says Dr Deepak Jayarajan, assistant professor, department of psychiatry, NIMHANS.

So, what are the chances of inheriting a mental illness?

*Sources:

Empiric Risk Data by National Coalition Professional Education in Genetics 
Does mental illness run in families?

These are worldwide numbers, and the risk of inheriting a mental illness signified is representative for the overall population. The statistics suggest that the risk of having a mental illness is higher if a first degree relative (parents or siblings) has been diagnosed with a mental illness. 

Are only genes responsible for mental illness?

No. Research points out that genes alone don’t typically cause mental illness and that there are other factors at play. Mental illnesses occur due to the interaction of genetic and environmental factors such as stress, abuse, childhood trauma, poverty and malnutrition. This means that even if an individual is carrying ‘risk genes’ (genes associated with a mental illness); the environmental and social factors can alter the way in which the inherited genes are expressed.Therefore, there are other factors involved that can trigger or precipitate a mental illness. Also, the chance of inheriting an illness reduces with age; as the onset age for most mental illnesses is 18-25 years. 

How will knowing the risk of inheriting the genes and other risk factors associated with mental illness help me? 

Now, you may wonder - how do the numbers indicated in the table translate to my situation? Knowing that you have a certain amount of risk for a mental illness due to inherited genetic vulnerabilities, and that other factors can alter gene expression, there are ways of reducing the risk. Just as in the case of diabetes and hypertension, the risk of inheriting a mental illness remains but can be reduced and altered by:

• Being aware of stress
• Improving your ability to handle and cope with emotional distress and challenges
• Bringing certain changes in your lifestyle to reduce the stress, if any
• Maintaining a healthy diet 
• Exercising regularly
• Getting enough sleep
• Talking about your problems to someone you trust
• Avoiding alcohol, tobacco and other mood altering substances. Consuming substances don’t just increase the risk of mental illness, but if you happen have a mental illness, they can change the course of the illness and thereby affect the effectiveness of medication.
• Knowing the potential signs of mental illness from a reliable source

Family members and caregivers who have any doubts or concerns about themselves or their children inheriting a mental illness can discuss with a psychiatrist and/or a genetic counsellor.