Researchers from Karolinska Institutet have discovered how a common Parkinson’s disease treatment, levodopa, can lead to serious psychiatric issues similar to drug addiction.
This complication, known as dopamine dysregulation syndrome (DDS), affects around 5% of Parkinson’s patients who take levodopa, a drug used to manage the disease’s motor symptoms.
Levodopa works by replacing dopamine, a brain chemical that is lost in Parkinson’s patients, which helps improve movement and reduce symptoms like tremors.
However, in some patients, levodopa causes them to feel under-medicated, leading them to take more than the prescribed amount.
This overuse can result in a harmful cycle of addiction-like behavior, where patients ignore recommended doses and self-medicate excessively.
This can cause additional problems, such as dyskinesia, which is uncontrolled, abnormal movements.
According to Gilberto Fisone, a professor at the Department of Neuroscience at Karolinska Institutet and the lead author of the study, this problematic behavior happens because levodopa hyperactivates a specific group of neurons in the brain’s reward system.
These neurons are usually linked to the effects of addictive substances, which explains why levodopa can cause behavior similar to drug abuse.
In their study, the researchers used a rodent model of Parkinson’s disease, which allowed them to recreate the complex pathology of the disease.
They found that the addictive-like effects of levodopa were due to the overstimulation of neurons with dopamine D1 receptors (D1R) in the basal ganglia, a part of the brain involved in movement and reward.
Fisone explains that this overactivation leads to changes in the transmission of signals between neurons and disrupts the function of specific proteins. These proteins could become targets for future treatments to prevent or reduce the psychiatric side effects of levodopa in Parkinson’s patients.
Next, the researchers plan to investigate the role of a protein called Delta-FosB, which is involved in regulating gene expression and is known to be linked to drug addiction.
They have observed that Delta-FosB levels increase in D1R neurons after levodopa is given.
The team believes that controlling the overexpression of Delta-FosB could help prevent DDS and improve the quality of life for Parkinson’s patients.
This new discovery sheds light on the complex effects of levodopa and provides hope for developing better treatments that minimize the psychiatric complications associated with this essential Parkinson’s drug.
If you care about Parkinson’s disease, please read studies that Vitamin B may slow down cognitive decline, and Mediterranean diet could help lower risk of Parkinson’s.
For more health information, please see recent studies about how wheat gluten might be influencing our brain health, and Olive oil: a daily dose for better brain health..
