[saltcured]

This is a bit like saying coughing is a symptom of the flu. It can be a symptom of the flu, but it can also be a symptom of something else... As best I understand it, schizophrenia may be an umbrella term, a bit like autism has been. We don't really know enough about the mechanisms to identify more specific diseases or conditions.

But, the core features for schizophrenia seem to be disturbed perception (hallucination), beliefs (delusion), and thought processes (abnormal reasoning, speech, and behavior). These can range from subtle or extreme over the life of the patient. The experience of these may lead to agitation, but mania often presents the other way around. The increasing energy seems to precede the other psychotic symptoms.

There are two other common conditions which also have many of the same symptoms, but not in the same pattern. Delirium is often a temporary condition when someone is sick or injured. Dementia is a terminal, degenerative condition. Sometimes a patient can have all of these: a lifetime of schizophrenia shifting into dementia in old age, punctuated with bouts of delirium due to infections etc. The differences may be recognizable and help with treatment plans, but the symptoms can all blur together. One way doctors try to distinguish them is by noting the timing of symptoms.