Selective deficits and Bipolar Disorder
11 February 2011
Recent genome-wide-association studies in Bipolar Disorder (BD) revealed a strong association with a variant of the ANK3 gene, which controls the firing of brain neurons. Research from the Institute of Psychiatry (IoP), King’ College London, showed, for the first time, how this gene may affect brain function.
The research team used data from the Vulnerability Indicators to Bipolar Disorders study (VIBES) to examine whether this risk gene impacts on core mental processes such as memory, decision-making, inhibition and attention. This investigation revealed that the risk gene has a selective effect on the ability to sustain attention over a prolonged period of time.
Dr Sophia Frangou, a Reader at the IoP and lead author on the research, said: ‘The ability to select the important details of what we see and to maintain that focus over time is fundamental to our every day function.
‘Our findings are important for three reasons. Firstly, they inform us about the function of the ANK3 gene about which very little is known. Secondly, they suggest that the risk gene affects the function of specific brain pathway that deals with attention. This links with clinical experience as problems in attention and concentration are amongst the earliest and the most common complaints of patients. Third, our findings point to a particular biological pathway leading from genes to disorder.’
The scans of one hundred and eighty-nine children carrying the risk gene revealed a disjointed brain, which means that the frontal lobe isn’t properly connected to the rest of the brain, and over-connected to itself. As a result, the frontal lobe “talks to itself” more than it talks to other regions of the brain, and lacks longer-range connections to the back of the brain.
The results suggest that variation in ANK3 impacts cognitive processes which may relate to risk for BD.
‘The Cognitive Impact of the ANK3 Risk Variant for Bipolar Disorder: Initial Evidence of Selectivity to Signal Detection during Sustained Attention’ is published in this month’s PLoS ONE Ruberto G, Vassos E, Lewis CM, Tatarelli R, Girardi P, Collier D, Frangou S (2011) PloS ONE. To read the paper in full, please follow the link