Is Mental Illness Hereditary?

What causes mental illness?

There are several causes of mental illnesses. And, each cause can impact the type of mental illness experienced. The most common causes include:

A person may be born with mental health issues if their mother experienced injury or trauma while pregnant. Other causes of prenatal injury may include consuming alcohol — which can lead to Fetal Alcohol Spectrum Disorders(FASDs) — as well as tobacco, and/or other controlled substances.

When the body has an infection, the immune system is activated to fight it. However, when the inflammation caused by the infection is chronic, the response of immune system cells may also cause damage to healthy brain tissue.

Trauma encompasses many aspects of human health — including abuse, emotional, sexual, or physical. Any event that causes physical or emotional injuries can lead to anxiety disorders, PTSD, borderline personality disorder, and/or depression.

Approximately half of all individuals with mental health issues also experience substance abuse and vice versa. Substance abuse can also lead to addiction, which is often accompanied by depression. Developing both disorders often results in a dual diagnosis of mental illness.

Your lifestyle and environment can contribute to your mental health. Pollution, long-term exposure to toxins — found in food treated with pesticides and/or antibiotics, the environment, personal hygiene products, and detergents — sleep deprivation, substance abuse, and/or hazardous conditions at your place of employment can all lead to mental illness.

The likelihood of developing a mental illness is higher for individuals with a family history of that same disorder. That being said, symptoms could range from mild to severe — even to a different degree than how it affected your family member. How your genes express themselves — epigenetics — will also determine whether you’ll develop a hereditary condition.

Although genes are certainly a risk factor, the development of mental illness doesn’t have to be your child’s destiny. For these genes to manifest a mental health condition, they have to encounter the right combination of epigenetics and environmental factors. Factors that can influence this include lifestyle, environment, and/or underlying health conditions.



One of the mental illnesses that is most likely to run in families is bipolar disorder. If one parent has the condition, their child has between 15% and 30% likelihood of developing it. If both parents are bipolar, the probability skyrockets up to 75%. It’s also possible for the child of a parent with mental health issues to experience trauma during childhood, increasing their own likelihood of developing other types of mental health issues in the future.

At St. Hope, we serve many patients living with a myriad of medical conditions. We believe that treating people with compassion is as important as the medicine they receive. We foster a trusting patient/medical provider relationship to ensure that everyone who walks through our doors feels comfortable and receives the care they deserve.



We take same-day appointments, accept all insurance plans, and welcome walk-ins. Call us at 713-778-1300 or visit us at one of our five locations.