If you have a mental disorder and are considering having children or already have children, one of the questions you are probably asking yourself is whether you could pass your mental disorder on to your child.
According to the National Institute of Mental Health, about 25% of US adults (ages 18 and older) and about 13% of US children (ages 8 to 15) are diagnosed with a mental disorder each year. Examples of mental disorders include:
- Depression – Affects 10% of the population.
- Attention Deficit-Hyperactivity Disorder (ADHD) – Affects 5%-11% of the population.
- Autism Spectrum Disorder (ASD) – Affects 1 in 68 children.
- Substance use disorders (addiction) – Affects 10% of the population.
- Schizophrenia – Affects 1% of the population.
- Bipolar Disorder – Affects 2%-3% of the population.
Diagnosing Mental Disorders
Doctors diagnose mental disorders based on the signs and symptoms of the individual patient. Doctors use the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) to assist in diagnosing mental disorders.
There are no genetic tests to confirm a diagnosis of mental disorder. Because experiences and environment play an important role in the development of a mental disorder, no genetic test will ever be able to tell with absolute certainty who will and who will not develop a mental disorder.
What does it mean if a mental disorder seems to run in my family?
The chance of an individual having a specific mental disorder is higher if other family members have that same mental disorder. Even though a mental disorder may run in a family, there may be considerable differences in the severity of symptoms among family members. This means that one person in the family may have a mild case, while someone else has a more severe case of the mental disorder. Mental disorders, however, do not follow typical patterns of inheritance.
Causes of Mental Disorders
Most mental disorders are caused by a combination of multiple genetic and environmental factors. This is called multifactorial inheritance. Many other common medical problems such as type 2 diabetes, obesity, and asthma also undergo multifactorial inheritance.
Environmental factors contributing to the development of mental disorders include:
- Trauma: Sexual, physical, and emotional abuse during childhood all lead to an increase in the likelihood of developing a mental disorder. Highly stressful home environments, loss of a loved one, and natural disasters are also major contributors.
- Emotional harm: Negative school experiences and bullying can also result in severe long-term emotional damage. The realization of these issues has led to anti-bullying campaigns nationwide, and the implementation of these campaigns has placed a larger importance on the overall mental health of school-aged children and teens.
- Substance Abuse: Exposure tobacco, alcohol, and illicit drugs either prenatally or in childhood has been associated with the development of mental disorders beyond just substance use disorders or addiction.
Environmental factors alone do not cause mental disorders. Genetic factors also play a part in developing a mental disorder.
Genetic factors contributing to the development of mental disorders include:
- Epigenetic regulation: Epigenetics affect how a person reacts to environmental factors and may affect whether that person develops a mental disorder as a result. Epigenetics is not constant over time. This means a gene is not always “on” or “off.” There must be the right combination of environmental factors and epigenetic regulation for a mental disorder to develop.
- Genetic polymorphisms: These changes in our DNA make us unique as individuals. A polymorphism alone will not lead to the development of a mental disorder. However, the combination of one or more specific polymorphisms and certain environmental factors may lead to the development of a mental disorder.
- Single gene changes: Rare.
Mental disorders are the result of both genetic and environmental factors. There is no single genetic switch that when flipped causes a mental disorder. Consequently, it is difficult for doctors to determine a person’s risk of inheriting a mental disorder or passing on the disorder to their children. The causes of mental disorders are complex, requiring many interacting genes and environmental factors.