Whether or not a young adult will abuse alcohol or engage in risky sexual behaviour could be predicted using brain scans, according to a research team from Duke University in the US.
The team set out to understand the communications between the brain, genome and environment that are the basis for risky activities foretelling mental illness such as depression, anxiety and addiction.
“By knowing the biology that predicts risk, we hope to eventually change the biology – or at least meet that biology with other forces to stem the risk,” says senior author Ahmad Hariri, a professor of psychology and neuroscience at Duke.
The team used non-invasive functional magnetic resonance imaging (fMRI) to observe the part of the brain that seeks rewards – the ventral striatum – and the part that weighs the consequences of risks – the amygdala.
Working with scans from participants – and later 759 students whose average age was 19 – they determined that an overcharged ventral striatum coupled with a lazy amygdala is a recipe for problem drinking.
Curiously, the inverse situation of having an underactive ventral striatum and a turbo-charged amygdala was also an indicator of problem drinking in the study, published in the journal Molecular Psychiatry.
“If you have high activity in both areas, no problem. If you have low activity in both areas, no problem,” says Hariri. “It’s when they’re out of whack that individuals may have problems with drinking.”
The underlying causes for the problem drinking in both cases could be different, according to Hariri.
Alcohol abuse could stem impulsively from a hyperactive ventral striatum, which, combined with a low-energy amygdala could make the individual less likely to curb his behaviour.
On the flip side, a ventral striatum with low demands for reward makes life seem bleak for the individual and a hyperactive amygdala could make him extraordinarily sensitive to stress and likely to drink as a way of coping.
A separate study, published in the Journal Of Neuroscience, revealed that equilibrium or lack thereof between these two brain regions could be an indicator of sexual behaviour.
Working with 70 heterosexual men and women, the researchers asked them how many sexual partners they acquired over the course of 11 months.
Men who had high levels of activity in the ventral striatum and an underactive amygdala had more sexual partners than those with a balanced brain.
Women proved to be more complicated, for the most promiscuous had high activity levels in both regions, indicating a propensity for thrills and sensitivity to threat that go hand in hand.
“It’s not really clear why that is,” says Hariri. “One possibility is that this amygdala signal is representing different things in men and women.” – AFP Relaxnews