Cause

Experts don't know what causes schizophrenia. It may have different causes for different people.

• Genetics: Your chances of getting schizophrenia are greater if your parent, brother, or sister has it. But most people who have a family member with schizophrenia don't get it.
• Brain chemistry and structure: It's possible that neurotransmitters, which send messages between parts of the brain, don't work the right way in people who have schizophrenia.
• Problems during pregnancy: Schizophrenia may be related to problems during the mother's pregnancy that can harm a baby's developing brain and nervous system. These problems include poor nutrition or a viral infection during pregnancy.

Schizophrenia is not caused by anything you did, by personal weakness or bad choices, or by the way your parents raised you.

Symptoms

The symptoms of schizophrenia can be negative, positive, or cognitive.

Negative symptoms

"Negative" doesn't mean "bad." Negative symptoms are things that are "lost" from your personality or how you experience life. You may:

• Find little or no pleasure in life. You may not enjoy things you once enjoyed, such as playing sports or video games or visiting with friends. This is a common symptom of schizophrenia.
• Feel like you have no emotions. You may not smile or frown, make eye contact, or use other facial cues that show how you feel.
• Have a hard time focusing or paying attention. You may not understand how to use information well, so you may feel confused. You may not have complete thoughts.
• Not be interested in succeeding or meeting goals. Many people with schizophrenia don't do well at work or in school.
• Not take care of yourself. You may not bother to wash, do laundry, eat on a regular basis, or clean your living space.

Positive symptoms

"Positive" doesn't mean "good." Positive symptoms are things "added" or "new" to your personality or how you experience life because of schizophrenia. You may:

• Have hallucinations. Most people with schizophrenia hear noises or voices that aren't there. Some people with the illness also may see, taste, touch, or smell things that aren't there.
• Have delusions, which are ideas that aren't true. For example, you may think that you are a powerful person or that the police or demons want to harm you or cause problems for you.
• Act oddly. You may become very excited or angry with other people. You may have odd body movements, such as often rocking back and forth or making faces.
• Show emotions that don't fit the situation. For example, you may smile when talking about sad topics or laugh at the wrong time.
• Not be able to keep your thoughts straight and not make sense to others when you talk. For example, when someone asks you a question, you may give an answer that doesn't make sense, not be able to say much, or only give one-word answers.

Cognitive and other symptoms

Other symptoms include:

• Cognitive symptoms. These symptoms affect how you think. They include memory loss and not being able to understand things well enough to make decisions. Cognitive symptoms often aren't obvious to you or others.
• Specific behavior changes.Different types of schizophrenia may cause different behaviors, such as being afraid with little reason, standing in awkward positions for a long time, or making up words.