Schizophrenia is a chronic and severe mental disorder that affects how a person thinks, feels, and behaves. People with schizophrenia may seem like they have lost touch with reality. Although schizophrenia is not as common as other mental disorders, the symptoms can be very disabling.
Symptoms of schizophrenia usually start between ages 16 and 30. In rare cases, schizophrenia has been found in children under the age of 16.
The symptoms of schizophrenia fall into three categories: positive, negative, and cognitive.
“Positive” symptoms are psychotic behaviors not generally seen in healthy people. People with positive symptoms may “lose touch” with some aspects of reality. Symptoms include:
“Negative” symptoms are associated with disruptions to normal emotions and behaviors. Symptoms include:
For some patients, the cognitive symptoms of schizophrenia are subtle, but for others, they are more severe and patients may notice changes in their memory or other aspects of thinking. Symptoms include:
There are several factors that contribute to the risk of developing schizophrenia.
Scientists have long known that schizophrenia sometimes runs in families. However, there are many people who have schizophrenia who don’t have a family member with the disorder and conversely, many people with one or more family members with the disorder who do not develop it themselves.
It is believed that many different genes may increase the risk of schizophrenia, but that no single gene causes the disorder by itself. It is not yet possible to use genetic information to predict who will develop schizophrenia.
Scientists also think that interactions between genes and aspects of the individual’s environment are necessary for schizophrenia to develop. Environmental factors may involve:
It is believed that an imbalance in the complex, interrelated chemical reactions of the brain involving the neurotransmitters (substances that brain cells use to communicate with each other) dopamine and glutamate, and possibly others, plays a role in schizophrenia.
Some experts also think problems during brain development before birth may lead to faulty connections. The brain also undergoes major changes during puberty, and these changes could trigger psychotic symptoms in people who are vulnerable due to genetics or brain differences.