The study was performed by the Bipolar Disorder Working Group of the Psychiatric Genomics Consortium, and compared the genetic variations in over 29.000 people with bipolar disorder and 160.000 healthy individuals.
The researchers found 30 positions in the DNA sequence that increase the risk of developing bipolar disorder, of which 20 were newly identified. In particular, the analyses pointed to genes relevant to the nervous, immune and metabolic systems.
There were also differences in the genetic make-up between individuals with bipolar 1 disorder, who have a history of severe manic episodes, and those with bipolar 2 disorder, who do not experience severe mania. Bipolar 1 was strongly genetically linked with schizophrenia, driven by psychosis, whereas bipolar 2 was more strongly linked with major depressive disorder.
Such analyses may be used to identify different sub-groups of individuals with bipolar disorder, and may provide useful information to develop new, more effective and tailored treatments and improve the management of bipolar disorder.
The results were recently published in the prestigious journal Nature Genetics. Professor Ole A. Andreassen from NORMENT was among the leaders of the study, and 13 NORMENT researchers and Norwegian collaborators also contributed.
Reference
Stahl et al. Genome-wide association study identifies 30 loci associated with bipolar disorder. Nature Genetics. 2019 May;51(5):793-803.