Study seeks to end guesswork for diagnosing mental illness

    14 December 2015

    Researchers at the University of Georgia have identified several biological markers for mental disorders.

    The research, published in the American Journal of Psychiatry, could lead to improved diagnostics and treatments for mental illness, they say.

    There are no objective medical tests to diagnose mental disorders, which means that doctors treating mental illness often rely on guesswork and trial and error.

    Brett Clementz, the study’s lead author, said: ‘Psychiatry still relies on symptoms as the basis of a diagnosis. It would be like using the presence of fever to diagnose a specific infection. We need some means to help us more accurately differentiate mental disorders.’

    Clementz and his colleagues have created an experimental programme that uses neurobiological measures to identify mental disorders. They aimed to differentiate between types of psychosis, which is a category of conditions ranging from schizophrenia to bipolar disorder.

    Mental health professionals use criteria in the Diagnostic and Statistical Manual of Mental Disorders, or DSM, to identify specific mental disorders based on reported symptoms. ‘We wanted to try to provide neurobiological underpinnings for DSM-type psychosis diagnoses,’ Clementz said.

    The researchers tested over 700 patients with psychosis. They were given examinations and an MRI scan to identify different ‘biotypes’ of mental disorders. They say that these proved to be superior to the traditional criteria.

    The researchers hope that their work will inspire a renewed interest in psychiatric drug development, which has been hampered by a lack of clear biological evidence.

    Clementz said:

    ‘Psychiatry has relied mostly on serendipity for new drugs. All of the medications that we use for psychosis have mostly the same mechanism of action, and there are no unique treatments for the various diagnoses.

    ‘You can’t, for example, use an animal model for schizophrenia. How do you find a schizophrenic mouse? But if we can identify a biological mechanism that contributes to disease, then we may reinvigorate drug development, and that’s what we’re trying to provide.’