A brain imaging study of young people at high risk of developing bipolar disorder has sound evidence of weakening connections between key areas of the brain in late adolescence.
Over the course of two years, persons with a high hereditary risk of bipolar disorder had less connectedness between emotion processing and cognition, while those with no family history had stronger relationships.
People with the illness are ten times more likely to develop it if they have a parent or sibling who has it. Professor Philip Mitchell of the University of New South Wales expects that new intervention tactics will be developed to lessen the effects of the condition.
Until now, medical researchers had known that bipolar disorder was linked to reduced communication between brain networks involved in emotional processing and thought, but how these networks originated before the condition was unknown.
Researchers from UNSW Sydney, the Hunter Medical Research Institute (HMRI), the University of Newcastle, and international institutions published a study today in The American Journal of Psychiatry showing evidence of these networks diminishing over time in young adults at high genetic risk of developing bipolar disorder, which has important implications for future intervention strategies.
Over the course of two years, the researchers scanned the brains of 183 people using diffusion-weighted magnetic imaging (dMRI). They compared the progression of alterations in brain scans of persons with a high hereditary risk of getting the illness to a control group of people with no risk during a two-year period.
Genetic links of bipolar disorder
People who have a parent or sibling with bipolar disorder are at a 10 times higher chance of developing the illness than those who do not have a close family connection.
During the two years between scans, the researchers noticed a loss in connectivity between regions of the brain devoted to emotion processing and cognition in 97 patients with a high genetic risk of bipolar disorder.
However, when the adolescent brain evolved to become more skilled at the cognitive and emotional reasoning necessary in adulthood, they saw the opposite: strengthening in the neural connections between these same regions in the control group of 86 people with no family history of mental illness.
The findings, according to Scientia Professor Philip Mitchell AM, a practicing academic psychiatrist with UNSW Medicine & Health, present fresh ideas for therapy and intervention in young persons at risk of developing bipolar disorder.
Professor Michael Breakspear, who headed the team at HMRI and the University of Newcastle that analyzed the dMRI images, said the study shows how technological advancements might possibly lead to life-changing breakthroughs in the treatment of mental diseases.
“Relatives of persons with bipolar disorder, particularly siblings and children, frequently inquire about their own future risk, and this is a very sensitive subject,” he says.
“It’s also a problem for their doctors because bipolar disorder has significant pharmaceutical consequences.”
Innovative approaches to bipolar disorder
“This study is an important step toward having imaging and genetic tests we can use to help identify those who are likely to develop the bipolar disorder before they develop the disorder’s disabling and stressful symptoms, bringing psychiatry closer to other branches of medicine where screening tests are part of standard care,” said Scientia Professor Philip Mitchell AM.
More research is needed, according to the experts, before present treatment methods are changed. It would also be impractical and expensive to have brain scans performed on everyone who has a genetic risk of developing bipolar disorder to assess if the brain is displaying evidence of reduced connectivity.
Prof. Mitchell adds, “The main conclusion of our study is that there is a progressive change in the brains of young people at risk of bipolar disorder, which underscores how crucial intervention tactics might be.”
“By improving our understanding of the neurobiology of risk and resilience in these high-risk individuals, we will be able to intervene and improve the quality of life of those who are most vulnerable.”
The researchers plan to conduct a third follow-up scan of study participants as a result of the new findings. They’re also working on building online programs to help young people develop resilience while also teaching them how to manage anxiety and depression, which they think will minimize their risk of developing a bipolar illness.