“Parkinson’s drug ‘helps’ the elderly think younger and reap the rewards from the choices they make,” according to the Mail Online. It reports that as you age you lose the ability to learn from experiences, which can lead to poor decision making. But the drug levodopa, used to treat Parkinson’s disease, could help the elderly to think again in a ‘younger manner’, it says.
Researchers speculate that the lower levels of dopamine found as people grow older could be harmful to the part of the brain that judges whether choices lead to beneficial rewards. Levodopa can increase levels of dopamine, so researchers wanted to see if it improved decision making skills.
In this study, a small group of older people performed tasks where making the correct decision could win them money. The researchers then looked at the effect that dopamine treatment had on their performance. They also compared the performance of these older adults with 22 healthy young adults.
They found that half of the older people improved performance with levodopa, but there was no improvement in the other half.
The research doesn’t tell us much more than how ageing may affect the chemical processes of the brain. Levodopa is only licensed for use in Parkinson’s conditions. Given the side effects of the drug, and that in this small study it only gave some benefit to half the participants, it is very unlikely that its use would ever be extended to all older adults, simply to boost decision making.
Where did the story come from?
The study was carried out by researchers from University College London and other institutions in the UK and Europe. Funding was provided by the Wellcome Trust.
The study was published in the peer-reviewed Nature Neuroscience.
Overall, the Mail Online’s reporting takes this small scientific research study a step too far, suggesting that the Parkinson’s drug can be used to treat older adults to help improve their decision making. This was scientific research exploring the chemical processes in the brain and how they may affect decision making, but it certainly has no therapeutic implications. Levodopa is licensed only for the treatment of Parkinson’s disease and related conditions.
Even if the medication was found to be effective (which is unproven by this study) it is unlikely it would be used simply to aid decision making, as the small benefits of the drug are unlikely to outweigh the risks. Most people would be unwilling to tolerate the side effects that can occur after levodopa use, such as nausea, vomiting, tiredness and dizziness.
What kind of research was this?
The researchers’ report that older adults are worse at making decisions when there are outcomes with different probability of reward led them to question what accounts for this poor decision making. Evidence from previous human and animal study suggests that an area of the middle of the brain, called the nucleus accumbens, has a key role in any decisions that may involve the likelihood of potential rewards and pleasurable emotions.
The nucleus accumbens is targeted by the chemical dopamine. Previous studies of brain samples of older adults have shown that there is a loss of dopamine nerve cells in certain areas of the brain that increases with age. So the reduction in dopamine levels and the subsequent effects on the nucleus accumbens may be responsible for the poorer reward-based decision making associated with ageing.
The current research used a sample of healthy older adults and gave them a task where they had two choices. At the same time they had functional magnetic resonance images (fMRI) taken, which measures the blood flow in the brain to show what areas of the brain are active.
They also had another special type of MRI scan called diffusion tensor imaging (DTI), which can identify any areas of the brain that are lacking oxygen. For this reason DTI is useful for examining people who have had a stroke, but also is a good technique for looking at conditions involving the nerve fibres (white matter).
The researchers compared the results for the older adults with the results from a sample of adults in their 20s. They also examined the effect of a placebo or the chemical levadopa (L-dopa – which is converted to dopamine in the brain and used in the treatment of Parkinson’s disease) on the older adults’ performance in the tasks….
Source: Read More at NHS