Researchers from the Royal College of Surgeons in Ireland (RCSI) and Beaumont Hospital have conducted a study which has found striking brain similarities in bipolar disorder and schizophrenia. The research has also pinpointed for the first time that a process which controls how information is transmitted from neuron to neuron in the brain is altered in both conditions and may potentially contribute to the developments of improved treatments in the future.

The study was the first to look at sub-regions in the part of the brain known as the hippocampus. Abnormalities in the hippocampus are among the most consistent findings in schizophrenia research and are also implicated in bipolar disorder. Certain areas of the hippocampus (cornu ammonis regions 2 and 3) were found to be different, in terms of how their proteins are affected, in people with schizophrenia and bipolar disorder compared to the general population. The differences observed in these regions were found to be almost identical in both conditions. A process which controls how information is transmitted by the shuttling of proteins to and from the synapse (a junction that permits a neuron to pass a signal to another cell) was also found to be is affected in both illnesses.

Professor David Cotter, Department of Psychiatry, RCSI and Beaumont Hospital commented: "Our study is the first to show the depth of protein similarities between schizophrenia and bipolar disorder as they appear in the brain and the processes associated with them. Although, the two conditions present with different symptoms, the research has shown that they are almost identical in terms of how they present in the brain," Professor Cotter concluded.