Preventing Schizophrenia

We wear seat belts when we drive in a car, so that we are protected if we get in an accident. When we are out in the sun, we wear sunscreen to protect our skin from the harmful effects of ultraviolet light. We know not to smoke cigarettes because it increases the likelihood that we will develop lung cancer.

Are there similar preventative measures we can take to prevent schizophrenia? Are there ways by which we can slow the development of this devastating illness?

Prevention of an illness can take two forms: primary and secondary prevention. The goal of primary prevention is to prevent new cases of a disorder from ever developing. One way we can do this with schizophrenia is improving prenatal and obstetric care. Pregnancy and birth complications have been linked to schizophrenia. Clinicians and researchers speculate that by improving health and nutrition in pregnant women, we may prevent the development of schizophrenia in their offspring.

There is a tremendous benefit from this approach, and there are no disadvantages. By improving prenatal care, we improve the health of the mother and the baby and increase the likelihood that both will be safe and healthy. Improving prenatal care is unlikely to cause any harm to the mother or the fetus. Still, because schizophrenia is caused by a whole host of factors, there is no guarantee that a child born to a mother who was healthy during pregnancy will not develop schizophrenia.

The goal of secondary prevention is to identify those who are most at risk of developing schizophrenia and treat them early.

This approach is problematic and has been the subject of great controversy. How does one identify someone at risk for schizophrenia? Can this be done with any degree of accuracy?

Relatives of schizophrenia patient are at risk, but not all relatives will develop the disorder. Another way researchers identify at-risk individuals is with a questionnaire that measures risk for psychosis. The questionnaire measures thoughts and behaviors that have been found to be indicators of future psychotic symptoms. Research has shown that 20 percent to 45 percent of people who score highly on this scale will eventually develop full-blown psychosis. The biggest problem with the secondary prevention approach is that it yields too many false positives.

Concepts of Prevention
The focus on psychosis as the core defining quality of schizophrenia (i.e., the reality distortion emphasis from Schneinderian firts-rank symptoms through DMS-IV) has led some workers to confuse early intervention with prevention. For example, Falloon described treating early psychotic manifestations, and patients who did not progress to full diagnostic criteria were considered instances of prevention.

This is more appropriately viewed as muting the severity of expression rather than prevention. Others have hypothesized secondary and tertiary prevention associated with early intervation. Here the hope is that the more effective management of the first episode will have long-lasting beneficial effects on the disease process. However, because effective psychosocial and antipsychotis drug therapies are not known to alter the course of cognitive and negative symptom pathologies, it seems doubtfull that disease progression is prevented.