Reviewed by John M. Grohol, Psy.D.
Researchers at Dartmouth College have found that exercise can benefit memory, as well as help children with attention deficit hyperactivity disorder (ADHD).
Over the past few years data has shown that exercise creates neurobiological changes, according to David Bucci, an associate professor in the department of psychological and brain sciences.
His latest research finds that the effects of exercise are different on memory, as well as on the brain, depending on whether the exerciser is an adolescent or an adult. Researchers have also identified a gene that seems to mediate the degree to which exercise has a beneficial effect, which has implications for the use of exercise as an intervention for mental illness, Bucci said.
He said he began his pursuit of the link between exercise and memory with ADHD, one of the most common childhood psychological disorders, noting he is concerned that the treatment of choice is medication.
"The notion of pumping children full of psycho-stimulants at an early age is troublesome," Bucci said. "We frankly don't know the long-term effects of administering drugs at an early age — drugs that affect the brain — so looking for alternative therapies is clearly important."
Anecdotal evidence from colleagues at the University of Vermont pointed Bucci toward studying exercise and ADHD. Researchers observed that ADHD children in Vermont summer camps, athletes or team sports players were found to respond better to behavioral interventions than more sedentary children. While systematic empirical data is lacking, this association of exercise with a reduction of characteristic ADHD behaviors was persuasive enough for Bucci.
Coupled with his interest in learning and memory and their underlying brain functions, Bucci and teams of graduate and undergraduate students embarked upon a series of experiments to investigate the potential connection between exercise and brain function.
Early on, they found that laboratory rats that exhibit ADHD-like behavior demonstrated that exercise was able to reduce the extent of these behaviors. The researchers also found that exercise was more beneficial for female rats than males, similar to how it affects male and female children with ADHD.
Next they investigated a mechanism through which exercise seems to improve learning and memory called brain-derived neurotrophic factor (BDNF), which is involved in the growth of the developing brain. The degree of BDNF in exercising rats correlated positively with improved memory.
The researchers also found that it had longer-lasting effects in adolescents compared to adults.
"The implication is that exercising during development, as your brain is growing, is changing the brain in concert with normal developmental changes, resulting in your having more permanent wiring of the brain in support of things like learning and memory," says Bucci. "It seems important to [exercise] early in life."
Bucci's latest paper was a move to take the studies of exercise and memory in rats and apply them to humans. The subjects in this new study were Dartmouth undergraduates and individuals recruited from the Hanover community.
According to Bucci, an interesting finding was that a person's genotype for BDNF affected whether exercise benefited learning and memory.
"This could mean that you may be able to predict which ADHD child, if we genotype them and look at their DNA, would respond to exercise as a treatment and which ones wouldn't," he said.
The notion that exercise is good for health, including mental health, is not a huge surprise, he concludes. "The interesting question in terms of mental health and cognitive function is how exercise affects mental function and the brain," he said.
Source: Dartmouth College