Psych II

Here it is the terms of Psych:
Mental disease is the disease of the brain, characterized by positive and negative symptoms and global changes of behaviour and personality.

Positive symptoms are those symptoms that are added to the clinical picture, including delusions, hallucinations, agitation.

Negative symptoms are characteristics of the patient that are subtracted form the clinical picture, includin such as poverty of thought and content of speech, social withdrawal and others.