Schizophrenia «SKIHT suh FREE nee uh », is a severe mental disease characterized by unpredictable disturbances in thinking. The word schizophrenia means a splitting of the mind. It refers to the characteristic schizophrenic behavior of withdrawing from reality and thinking in illogical, confused patterns. The term does not mean that a patient has more than one personality. .
Schizophrenia is one of the most common mental disorders. It afflicts about 1 percent of the world's population. Most patients develop the disease from their late teens to mid-20's. Men tend to develop it earlier than women and often more severely.
Many people with schizophrenia develop delusions and behave as though they live in a fantasy world. They may hear "voices" that others cannot hear. The patients may believe that these "voices" carry messages from important people, or even from God. Schizophrenics often suffer disturbances in mood and behavior. Some patients seem to feel no emotions, but others may display inappropriate emotions, such as laughing at sad situations. Some patients withdraw from their family and friends and talk mainly to themselves or to their "voices.".
Physicians do not know the cause of schizophrenia. Viral infections, drug abuse, or trauma during birth may increase a person's risk of developing the disease. Genetic factors may be partly responsible for some cases. Abnormal brain chemistry also plays a role. Chemicals called neurotransmitters, which allow nerve cells to communicate with each other, have been found at abnormal levels in some people with schizophrenia. In addition, medical imaging studies show that schizophrenics have less neural tissue, called gray matter, in their brains than healthy individuals. This loss of brain tissue occurs in regions controlling short-term memory, which is also impaired in patients with schizophrenia. In individuals who develop a severe case of the disease early in life, the loss of gray matter progresses over time, with worsening hallucinations and depression.