Hi, I'd like to help you with your question.
Psychosis is used to describe someone who has lost touch with reality. When a person loses touch with reality they are said to be psychotic. This symptom is found in people who have been diagnosed with schizophrenia, Bipolar I disorder, or certain personality disorders. It is a loose term that some therapists feel does not adequately describe a disorder but rather broad range of thought disorders.
A person who has psychosis can have hallucinations, delusions, and thought disorder. It is thought that psychosis is caused by mental illness, brain disorders such as tumors, dementia, or stroke.
It is thought that schizophrenia and Bipolar can be inherited. People who have parents or other relatives with these disorders have a slightly more increased chance of developing the disorder than in families without the diseases. Psychosis itself is not necessarily inherited.
Although your grandfather may have had psychotic symptoms, it is not clear what the cause of his symptoms were. It could have been a brain disorder or other cause not related to schizophrenia. And his daughter may also have something else wrong besides schizophrenia or Bipolar. If you feel you do have some symptoms, you may need to be evaluated by a trained therapist or psychiatrist that can help you pinpoint your symptoms better so you can get a definitive diagnosis. You can try asking your doctor for a referral or you can search on line at http://www.bacp.co.uk/ or http://www.itsgoodtotalk.org.uk/therapists/.
I hope this has helped you,