Researchers from McGill University have developed a new understanding of the neurobiology of impulsivity. This is using a genetically based impulsivity score, designed to help identify children who are especially vulnerable to ‘impulsivity’.
This matters because impulsivity has bene linked, in young people, with depression, and other forms of mental illness, and substance abuse.
Impulsivity is the tendency to act without thinking, for example if you blurt something out, buy something you had not planned to. Commonly, impulsivity is characterized by failure in inhibiting a potentially risky impulse for the individual or the others around. This is an area that can be subject to neuropsychological assessment.
Identifying mechanisms to spot and treat those who appear particularly vulnerable to impulsivity early in life is especially important. The new approach is by using a genetically based score.
The score was developed by examine three ethnically diverse community samples of children, taken from a cohort of around 6,000 children.
The score was constructed by the co-expression of several genes located in the prefrontal cortex and the striatum. These are areas of the brain that play a role in decision-making and emotional regulation. This approach was based on earlier work in mice models, before tests were undertaken on the human subjects.
Of particular importance is a gene called DCC. This gene acts as a “guidance cue” that determines when and precisely where brain dopamine cells form connections in the prefrontal cortex and striatum. Earlier studies have shown genetic variability within the Netrin-1 guidance cue receptor gene, DCC, and several psychiatric disorders.
The research showed that this coordinated development is essential for the maturation of impulse control. However, to develop the score, the researchers had to track down the genes most closely associated with DCC.
It is hoped that by describing the function of the gene networks that make up the score, the study will stimulate additional research aimed at the development of new therapies in the future.
The research appears in the journal Molecular Psychiatry, titled “Corticolimbic DCC gene co-expression networks as predictors of impulsivity in children.”
