Mental illness runs in families. The best available method to estimate an individual’s risk of mental illness is to look at their family history. However, family history information is limited, and it is not always known in full. It is also possible to estimate genetic predisposition to mental illness and other traits using polygenic scores (sums of all relevant gene variants across the genome).
Researchers at Dalhousie University wanted to know if these scores could help identify which youth are at higher risk of developing mental illness. Using blood and saliva samples, they calculated the scores from 1,884 young people in eight studies from across the world. Of those, 1,339 had parents with mood or psychotic disorders. The Heinz C. Prechter Bipolar Research Program contributed data for this research.
The Dalhousie research team found that youth with greater genetic predisposition to neuroticism (a personality trait linked to anxiety and mood problems) were more likely to develop major mental illness by adulthood.
They also found that youth with greater genetic predisposition to subjective well-being were less likely to develop major mental illness.
The results suggest that polygenic scores may be used in combination with other information, such as family history, to help identify which youth may benefit from early interventions. Prechter Program Director Dr. Melvin McInnis is listed as a co-author on the study.