Schizophrenia is a diagnostic category covering a broad range of disorders that have at their core a combination of psychotic symptoms, such as hallucinations, delusions, and thought disorganization (often referred to as positive symptoms, not because they’re good things to have, but because they’re extreme and readily apparent) and a type of blunting and flattening of emotion often accompanied by extreme apathy and lack of motivation (negative symptoms).
As with bipolar disorder, people with schizophrenia can appear many different ways, and there can be a great deal of overlap when someone is in an emergency room in a psychotic state. Being able to differentiate the psychosis of schizophrenia from that which can accompany a mania or depression is not easy. What ultimately makes the difference is that in bipolar disorder, if psychosis accompanies a mood episode, it resolves when the mood returns to a normal state. In schizophrenia, regardless of the person’s mood, the psychosis may persist.