Signs and Symptoms
Symptoms of schizophrenia usually start between ages 16 and 30. In rare cases, children have schizophrenia too.
The symptoms of schizophrenia fall into three categories: positive, negative, and cognitive.
Positive symptoms: “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:
- Thought disorders (unusual or dysfunctional ways of thinking)
- Movement disorders (agitated body movements)
Negative symptoms: “Negative” symptoms are associated with disruptions to normal emotions and behaviors. Symptoms include:
- “Flat affect” (reduced expression of emotions via facial expression or voice tone)
- Reduced feelings of pleasure in everyday life
- Difficulty beginning and sustaining activities
- Reduced speaking
Cognitive symptoms: 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:
- Poor “executive functioning” (the ability to understand information and use it to make decisions)
- Trouble focusing or paying attention
- Problems with “working memory” (the ability to use information immediately after learning it)
There are several factors that contribute to the risk of developing schizophrenia.
Genes and environment: 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.
Scientists believe 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:
- Exposure to viruses
- Malnutrition before birth
- Problems during birth
- Psychosocial factors
Different brain chemistry and structure: Scientists think 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.