According to study in the January, 2005 issue of the Archives of General Psychiatry the anti-psychotic drugs used to treat Schizophrenia are linked to an increased risk of insulin resistance.
"Harvard Medical School researchers in Boston said the anti-psychotic drugs clozapine and olanzapine are linked to an increased risk of insulin resistance.
Their study, in the January issue of The Archives of General Psychiatry, said insulin resistance is a major risk factor for diabetes."
It's funny this should come up again because I had seen this report before, and one of our patients at GCASA where I work asked me about this a couple of months ago. He is what is referred to in New York State as a MICA patient, Mentally Ill Chemical Abuser. He is doing well with his substance abuse recovery, but struggles which Schizophrenia and is taking olanzapine and has been gaining weight. He told me that someone had told him about the risk of getting diabetes and wondered if he should stay on his meds. I am not his therapist and so referred him back to the psychiatrist prescribing his meds and said he should discuss it with him.
These are the tough questions asked in health care settings where patients need information to make informed consent having weighed the benefits against the possible risks.