Signs and Symptoms.

A person diagnosed with schizophrenia may demonstrate auditory hallucinations, delusions, and disorganised and unusual thinking and speech. These may range from loss of train of thought and subject flow, with sentences only loosely connected in meaning. Social isolation commonly occurs for a variety of reasons. Impairment in social Congnition is associated with schizophrenia, as are symptoms of paranoia from delusions and hallucinations, and the negative symptoms of apathy or lack of motivation also know as avolition. In one uncommon subtype, the person may be largely mute, remain motionless in bizarre postures, or exhibit purposeless agitation. These are signs of catatonia. No one sign is diagnostic of schizophrenia, and all can occur in other medical and psychiatric conditions. The current classification of psychoses holds that symptoms need to have been present for at least one month in a period of at least six months of disturbed functioning. A schizophrenic-like psychosis of shorter duration is termed a schizofreniform disorder.
Late adolescence and early adulthood are peak years for the onset of schizophrenia. These are critical periods in a young adult's social and vocational development, and they can be severely disrupted. To minimize the effect of schizophrenia, much work has recently been done to identify and treat the pre-onset phase of the illness, which has been detected up to 30 months before the onset of symptoms, but may be present longer.
Those who go on to develop schizophrenia may experience the non-specific symptoms of social withdrawal, irritability and dysphora in the prodromal period, and transient or self-limiting psychotic symptoms in the prodromal phase before psychosis becomes apparent.