It hasn’t happened quite yet, but advances in brain scanning technology mean that in future doctors will most likely be able to diagnose mental illnesses, including depression, schizophrenia and bipolar disorder using brain scans.

At the moment there is no biological or physical test for mental illness, and the presence, or not, of disease is down to the experience and the judgement of the consultant psychiatrist.

The decision as to whether a person is mentally ill or not is based on verbal responses, and close observation of body language and things like personal hygiene.

There are plenty of technical obstacles to overcome first, but in future doctors should be able to use brain scans not only to confirm the presence of mental illness, and then to determine how well prescribed medication is working in the brain.

The Clinical Neuroimaging Laboratory in NUI Galway has studies underway using brain scans to look at volunteers that have psychosis and bipolar disorder.

Listen: Interview with Dr Dara Cannon, Co-Director of the Clinical Neuroimaging Lab at NUIG

Broadcast on Science Spinning on 103.2 Dublin City FM on 08.12.2011