A world-first study claims to have ‘mapped-out’ the bipolar brain, in a bid to identify how the condition affects certain brain regions, such as those associated with inhibition, emotion and motivation.

The research, which was carried out by scientists at the University of Oslo in Norway in collaboration with the ENIGMA consortium, is the largest ever brain-scanning study into the effects of the condition, which is thought to affect up to three in every 100 people.

Scientists MRI-scanned the brains of more than 6,500 people – 2,447 of which had previously been diagnosed with bipolar disorder.

Through comparing the scans, the study found “important clues” as to how the condition affects the brain – predominantly in terms of its grey matter.

The study found that grey matter – which is made up of the bodies of nerve cells – was typically ‘thinner’ in specific regions of the brain in people with the condition. This difference was found to be most profound in the regions associated with motivation and inhibition.

The research also found that patients who had been taking certain treatments for bipolar disorder – such as lithium or anti-psychotic and anti-epilepsy treatments, appeared to have less ‘thinning’ of grey matter in these areas.

Ole Andreassen, of the Norwegian Centre for Mental Disorders Research at the University of Oslo, said: “We created the first global map of bipolar disorder and how it affects the brain, resolving years of uncertainty on how people’s brains differ when they have this severe illness”.

Study co-author and director of the ENIGMA consortium, Paul Thompson, said: “This new map of the bipolar brain gives us a roadmap of where to look for treatment effects.

“By bringing together psychiatrists worldwide, we now have a new source of power to discover treatments that improve patients’ lives”.

The World Health Organisation (WHO) estimates that approximately 60 million people worldwide are affected by bipolar disorder.