Health Conditions

What causes it?

The causes of schizophrenia are still not completely understood. Many theories, including hereditary factors, environmental factors, chemical imbalances in the brain, and physical brain development abnormalities, exist. Most likely, a combination of these factors leads to schizophrenia.

There is increasing evidence that schizophrenia is a genetic illness. It has long been known that the mental illness can run in families. It is not clear which genes are involved and how the genetic predisposition is transmitted. And, at this point, science cannot predict whether offspring or siblings of a person with schizophrenia will develop the mental illness.

Environmental factors are merely speculative and may include complications during pregnancy and birth. For instance, some studies have shown that offspring of women whose sixth or seventh month of pregnancy occurs during a flu epidemic are at increased risk for developing schizophrenia although other studies have refuted this. During the first trimester of pregnancy, maternal starvation or viral infection may lead to increased risk for schizophrenia development in the offspring. It has even been conjectured that babies born in the winter season are at higher risk for developing this mental illness in their early adulthood. These, however, are just theories that have not been proven.

Scientists are researching the possible role of chemical imbalances in the brain as a causative factor for schizophrenia. Although the roles of the chemicals are not completely known, scientists think that an imbalance of the neurotransmitters-- substances that allow communication between nerve cells--dopamine and glutamate may be a likely link to schizophrenia.

Finally, abnormalities in brain development may predispose an individual to developing schizophrenia. Scientists have performed brain-imaging scans in patients with schizophrenia and have found subtle abnormalities such as enlarged ventricles (natural fluid-filled spaces in the brain), decreased size of certain brain regions, and changes in the distribution and number of brain cells. Evidence also exists that schizophrenia may be a developmental disorder resulting from neurons (nerve cells) establishing inappropriate connections and abnormal brain circuits during fetal development.