positive symptom n. <pos-i-tiv simp-tum> {psychology}

A positive symptom in schizophrenia is the presence of "abnormal" behaviour. This can be things such as hallucinations, delusions, urination at inappropriate times, neologisms, and so on. Contrast this with a negative symptom, which is the lack of "normal" behaviour.

Examples:
hallucinations (visual and auditory), outbursts, inappropriate behaviours.