Schizophrenia

Schizophrenia is  the most chronic and disabling of mental disorders.  It is considered a severe mental disorder. This is associated with abnormalties of  the brain structure, disorganized speech and behavior, and hallucinations. The symptoms of schizophrenia can appear at any time. The symptoms most likely appear when a person is around eight years old. Schizophrenia that appears after age 45 is considered late-onset schizophrenia. About 1%-2% of cases are diagnosed in patients over 80.

Source: http://www.minddisorders.com/Py-Z/Schizophrenia.html

Kleptomania

Kleptomania is an irresistable urge to steal items of value. People with this mental disorder are naturally compelled to steal things. But these people steal objects that have limited or no vaule such as pens, pencils, paper clips, and tape.  Some kleptomanincas are not aware that they committed theft. People with this mental disorder are most likely to be paranoid. Kleptomania can occur after a traumatic accident or brain surgery.


Source: http://en.wikipedia.org/wiki/Kleptomania