The symptoms are classified into four categories:
・Positive symptoms - also known as psychotic symptoms. For example, delusions and hallucinations.
・Negative symptoms - these refer to elements that are taken away from the individual. For example, absence of facial expressions or lack of motivation.
・Cognitive symptoms - these affect the person's thought processes. They may be positive or negative symptoms, for example, poor concentration is a negative symptom.
・Emotional symptoms - these are usually negative symptoms, such as blunted emotions.
