Young adults who experienced annual income drops of 25 per cent or more might be more at risk of having thinking problems and reduced brain health in middle age, a study said.
"Our exploratory study followed participants in the US through the recession in the late 2000s when many people experienced economic instability," said the study's lead author Leslie Grasset from the Inserm Research Centre in France.
"Our results provide evidence that higher income volatility and more income drops during peak earning years are linked to unhealthy brain ageing in middle age," Grasset said.
The study published in the journal Neurology, involved 3,287 people who were 23-35 years old at the start of the study and were enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study, which includes a racially diverse population.
Participants reported their annual pre-tax household income every three to five years from 1990-2010.
Researchers have examined how often income dropped as well as the percentage of change in income between 1990-2010 for each participant.
Participants were given thinking and memory tests that measured how well they completed tasks and how much time it took to complete them.
The study found that people with two or more income drops had worse performances in completing tasks than people with no income drops.
Participants with more income drops also scored worse on how much time it took to complete some tasks.
The results were the same after researchers adjusted for other factors that could affect thinking skills, such as high blood pressure, education level, physical activity and smoking.
There was no difference between the groups on tests that measured verbal memory.
Of the study group, 707 participants also had brain scans with magnetic resonance imaging (MRI) at the beginning of the study and 20 years later to measure their total brain volume as well as the volumes of various areas of the brain.
Researchers found when compared to people with no income drops, people with two or more income drops had smaller total brain volume.
People with one or more income drops also had reduced connectivity in the brain, meaning there were fewer connections between different areas of the brain.
