Research has not yet determined whether schizophrenia is a single disorder or a group of related illnesses. The illness is highly complex, and few generalizations hold true for all people diagnosed with schizophrenia disorders. However, most people initially develop the symptoms between the ages of 15 and 25. Typically, the illness is characterized by thoughts that seem fragmented and difficulty processing information.
Symptoms of schizophrenia disorders are categorized as either "negative" or "positive." Negative symptoms include social isolation or withdrawal, loss of motivation, and a flat or inappropriate affect (mood or disposition). Positive symptoms include hallucinations, delusions, and thought disorders.