Scared about speaking in public? Nervous about a job interview? These anxious feelings are familiar to most of us. But while some people are able to sweep them under the rug, for others, anxiety can become such a problem that it controls their day-to-day lives. And according to a new study, it may even lead to bad decision-making.
Lead author Bita Moghaddam, of the Department of Neuroscience at the University of Pittsburgh in Pennsylvania, and colleagues publish their findings in The Journal of Neuroscience.
According to the National Alliance on Mental Illness (NAMI), anxiety disorders - including post-traumatic stress disorder (PTSD), panic disorder and social anxiety disorder - affect around 18.1% of the population in the US.
Moghaddam and her team note that previous research investigating the effects of anxiety on the brain has primarily focused on the emotional response, such as how the brain cells of animal models respond to threatening situations.
But anxiety does not only have emotional implications for humans; it can also negatively impact everyday life, from preventing a person going to work, to interfering with personal relationships.
As such, the team set out to investigate how anxiety impacts one key aspect of day-to-day life: decision-making - defined as the cognitive process of making a choice from a number of possible alternatives.
Anxiety interferes with choice-making cells in the prefrontal cortex
To reach their findings, the researchers analyzed the brain cells, or neurons, in the prefrontal cortex (PFC) of two groups of rats as they completed a decision-making task, in which they had to make a decision about which choice was most logical for receiving a reward.
The PFC is an area of the brain that plays a key role in flexible decision-making.
One group of rats received a low-dose anxiety-inducing drug prior to the task, while the other group received a placebo injection.
While the anxious rats did complete the decision-making task - as would humans with anxiety - the team found that the rodents made significantly more mistakes than the non-anxious rats when the decision-making process involved ignoring distracting information to reach a logical choice.
The researchers found that these mistakes were down to anxiety's effects on a group of neurons in the PFC that code specifically for making choices; anxiety hampered their coding ability.
Overall, the team believes the findings indicate that anxiety may interfere with our ability to make good decisions by interfering with a specific set of neurons in the PFC.
Commenting on the findings, Moghaddam says:
"We have had a simplistic approach to studying and treating anxiety. We have equated it with fear and have mostly assumed that it over-engages entire brain circuits. But this study shows that anxiety disengages brain cells in a highly specialized manner."
She adds that gaining a better understanding of how anxiety affects decision-making could eventually lead to improved treatments for anxiety disorders and other psychiatric illnesses.
In January, Medical News Today reported on a study suggesting anxiety may increase the risk of dementia by affecting the PFC and amygdala regions of the brain.