Schizophrenia is an illness that is not easily defined. There is no single symptom that is found only in schizophrenia, but there are several that are somewhat uncommon in other diseases. Contrary to popular stereotype, it is not a "split personality". Rather it is an illness that affects the performance of the brain. As such, it is often referred to as a brain disease.
An individual with schizophrenia will most likely experience some of the following symptoms: thoughts becoming disjointed and jumbled; communication that is disorganized so that it is hard to follow; or, thinking that is so distorted that it is difficult to separate that which is real from that which is not real. Schizophrenia also affects the individual's emotional life, causing him/her to have difficulty relating to family members and others, and in forming relationships.
Schizophrenia can be a frightening and humiliating experience because it often leads to a decrease in the individual's level of functioning. The individual becomes very disturbed by this since the basic normal intellectual functioning of the individual remains intact. The individual has a more difficult time fulfilling the basic responsibilities of his own life. Independent living skills are not adequate and must be relearned. In addition, the person typically experiences a loss of drive or ambition, a loss of will, and a withdrawal from family and friends resulting in the loss of a natural support system. The individual is very vulnerable to stress, and at the same time experiences a decreased ability to cope and learn from past experiences. Hallucinations and delusions may also be a symptom of this thought disorder called schizophrenia. Hallucination (voices) are experienced as real. Severe thinking problems can occur. Delusions are false beliefs either about whom he/she is or feeling that his/her thoughts are broadcast to or controlled by others. These symptoms have a very frightening and disorganizing effect.
Seventy-five percent of the people who develop schizophrenia will have the symptoms before the age of 25. The illness usually occurs in late adolescence and often interferes when the individual is developing his/her own social and vocational potential. Researchers today believe that a predisposition to schizophrenia is inherited. If one has a brother, a sister, or one parent with the disorder, he/she has about a ten percent chance of developing schizophrenia. We also know that schizophrenia is not caused by bad parenting or environmental factors in early childhood.
Schizophrenia is a serious mental disorder which tends to be intermittent and long-lasting. During the last several decades with significant advancements in research and medication, the outlook for individuals with schizophrenia has improved significantly. While we still do not have a cure for schizophrenia, the illness is very treatable and improvement is nearly always possible. Services such as those offered by Community Alliance can help the individual deal with the symptoms of the illness by creating a routine and low stress environment. This also serves to enhance the rehabilitation and recovery process and prevent relapse of the illness. 
Information was gathered on this topic and additional resources are available from the following sources:
National Institute of Mental Health (NIMH)
National Alliance on Mental Illness (NAMI)