New York, Dec 5 (IANS): People with mental illnesses are more likely to have been tested for HIV than those without such disorders, a new study says.

The researchers also found that those seriously ill - afflicted with schizophrenia and bipolar disease - had the highest rate of HIV (human immuno-deficiency virus) testing.

The team from Penn Medicine and the US Centers for Disease Control and Prevention (CDC) assessed nationally representative data from 21,785 adult respondents from the 2007 National Health Interview Survey (NHIS). The 2007 version is the most recent cycle of the survey that included information both on mental health diagnoses and HIV testing.

The researchers found that 15 percent of the respondents reported a psychiatric disorder.

Of these, 89 percent had symptoms of depression and/or anxiety, 8.5 percent had bipolar disorder and 2.6 percent had schizophrenia spectrum disorder.

Among persons reporting at least one mental illness, 48.5 percent had been tested for HIV.

"The 48.5 percent rate compares with a testing rate of 35 percent among those without mental illness," the authors noted.

More specifically, 64 percent of persons with schizophrenia, 63 percent of persons with bipolar disorder and 47 percent of persons with depression and/or anxiety reported being tested for HIV.

"Our study shows that persons with mental illness and/or their care providers recognise that they are at higher risk and should be tested," said senior author Michael B. Blank, associate professor of psychiatry at the University of Pennsylvania in the US.

The research appeared in the journal AIDS Patient Care and STDs.