“What mental illness can cause psychosis?”

Other than schizophrenia, Dementia sometimes can cause psychosis. Severe depression or mania is also associated with psychosis.

At her age, I would take her to a doctor to check for a urinary tract infection, evaluate her medication regimen, dementia, infection, thyroid disease. Also consider a head cat scan to rule out any brain lesions. I would also check into a family history of schizophrenia and environmental exposures.

Psychosis is a symptom found in many psychiatric and non-psychiatric diagnoses. There are also many many forms of psychosis. To understand how a psychotic experience happens, there needs to be a very thorough neurological and medical intake history and physical exam, often in addition to many laboratory exams. Establishing the cars or probable cause of the psychosis is critical in both acute and long-term treatment. My advice would be to have a very thorough work up by a neurologist in addition to a psychiatrist. This is an absolutely critical part of treatment. Best of luck! Lots of hope and help!

Psychosis onset typically has a “bimodal” peak, meaning that it usually either starts at an early age or late age. Early age onset psychosis, usually around age 15-25, has different causes than late-onset psychosis (after 65). After 65, psychosis is usually caused by something neurological, medical, or medication-induced. Neurological causes may include dementia, stroke, or neurodegenerative disorders (such as Parkinson's or Huntington's disease. Medical causes may include delirium from an underlying cause, such as a urinary tract infection or pneumonia. Medications inducing confusion or psychotic symptoms are extremely common. Older individuals are very sensitive to the side effects of medicine, particularly antihistamines or sedatives, and this should be ruled out first.

At this age, probably dementia can or if she had depression that can also cause it. It's hard to say without doing an evaluation.