Positive symptoms can be thought of as those symptoms that are in addition to what others without schizophrenia might experience. Positive symptoms include delusions and hallucinations. Delusions are strong beliefs that don’t fit with the person’s culture. These beliefs persist even if not true or logical. For example, a person may think that the FBI is spying on them or they may believe they are famous or that the radio is speaking directly to them. Hallucinations include perceiving things that others do not. This may include any of the five senses. For example, a person may perceive that they see something like a crowd of people or that they hear something like a voice.
Negative symptoms can be thought of as those symptoms that are a deficit to what others without schizophrenia might experience. Negative symptoms include decreased thought and speech productivity (alogia), loss of ability to experience pleasure (anhedonia), decreased initiation of goal-directed behavior (avolition), and speech with little or no change to their tone, little or no change in their facial expression, even if they are talking about something upsetting or exciting (affective flattening). The person may have trouble starting tasks or sustaining activities over a period of time.
Disorganized symptoms include disorganized speech (frequent derailment and incoherence), and disorganized behavior and attention. For example, the person may have trouble organizing their thoughts or behaviors. Conversations with them might be hard to follow because they jump from one topic to another, sentences do not seem to follow from the one before, words may be made-up or strung together in a way that does not make sense. Additionally, the person may behave in ways that others view as bizarre or without purpose.