Schizophrenia is defined as any of a group of psychotic disorders, usually characterized by withdrawal from reality, illogical patterns of thinking, delusions, and hallucinations accompanied by other emotional behavioral or intellectual disturbances. (American Heritage dictionary, 1219)
Mania, or manic the other side being depression results in poor judgment. The inability to come oneself during a manic episode often leads to drug or alcohol abuse. It is considered to be the disease of highly intelligent and creative individuals and many famous authors, musicians, have committed suicide during the use of poor judgment to solve their problems. (American Heritage dictionary, 824)
Depression, despondent understood in the mental health field as anger directed at one self and clouds judgment.
Compulsion, obsessive-compulsive usually are driven and have no control over their habit. Usually the habit is ritualistic.
Paranoia fearfulness for reasons that do not appear to be threatening to a reasonable person.
Further definition and descriptions of the vocabulary above can be found in the DSM IV manual.