Schizophrenia sometimes runs in families according to the National Institute of Mental Health. However, there is more to the cause then your genes. Many people who have schizophrenia do not have a family member with it and many people with schizophrenia have family members who never developed it. So genes may play a role in raising your risk of developing schizophrenia, they don’t cause it.

For those who developed schizophrenia as adolescents and young adults, family history is more prevalent, however, for those who developed late-onset schizophrenia, family history was not as prevalent and psychosocial factors, such as unemployment, were more likely to trigger the onset of the disease according to a study published in 2018.

Complications during birth, such as preeclampsia, malformations, vacuum extraction, and nerve compression during birth may increase the risk of schizophrenia according to a review of previous studies.

Some experts believe that problems in brain development before birth can result in faulty connections according to the National Institute of Mental Health. The brain changes that occur during puberty may trigger schizophrenic symptoms in people with the faulty connections.

One study found that 59 percent of males and 69 percent of females hospitalized for schizophrenia suffered childhood trauma including physical and emotional abuse. Other stress can include head injury, family breakdown, or a death in the family. In addition, children whose mothers experienced severe stress or mental disorders while pregnant had a higher risk for developing schizophrenia.

Neurotransmitters are substances in the brain that are used to help brain cells communicate with one another. Some scientists believe that an imbalance of the neurotransmitters dopamine and glutamate play a role in schizophrenia according to the National Institutes of Mental Health.

Exposure to bacterial and viral infections, including influenza, before birth is a risk factor for developing schizophrenia. Children whose biological mothers developed measles during pregnancy are also at risk of developing psychosis and schizophrenia.

Children born at the end of winter or early part of the spring may be more at risk of developing schizophrenia. The possible connection with influenza may contribute to this. The lack of vitamin D during the winter months may also result in problems with fetal growth and brain development.

The lack of a healthy diet during pregnancy may also be related to the development of schizophrenia according to the National Institute of Mental Health. Particularly, the lack of unsaturated fatty acids may play a role.

Research is ongoing to try to determine or better understand the causes of schizophrenia. For example, in 2017, a study at the University of Copenhagen found genetic defects that occurred in the embryonic stage. And in 2016, Harvard Medical School studied gene variants as they related to schizophrenia. Scientists believe if they can find the cause, it will lead to more effective treatments.