This clinical trial looks to see if the medication memantine, when taken together with your current medication (an acetylcholinesterase inhibitor, such as donepezil, rivastigmine, or galantamine) can help improve symptoms for people with Parkinson’s Disease Dementia or Dementia with Lewy Bodies.

What Happens In This Study?

You will either be given a medicine called memantine or a placebo (a dummy pill that looks like the medicine but has no active ingredients). Neither you, nor the research team, will know which group you are in.

Can I Join This Study?

To take part in this medical trial, you must meet these 6 requirements:

1. Your Diagnosis: A doctor must have confirmed that you have Parkinson’s disease dementia OR Dementia with Lewy Bodies.
2. Your Age: You are 55 years old, or older.
3. Your Current Medicine: You must have been taking the same Parkinson’s medication (an acetylcholinesterase inhibitor) for at least the last 3 months without making any big changes to it.
4. Your Study Partner: You must have a reliable friend of family member who knows you well and helps to care for you, who can also take part, to provide us with information on how you are doing.
5. Your Time: You must do your best to attend all your study visits, and follow the rules of the study until it ends.
6. Taking the Medicine: You must be willing and able to swallow the trial medication.

Study Length: 56 weeks (1 year and 1 month)

Number of appointments: 3 visits, plus check in phone calls (with an optional follow up one year later)

More information on the trial can be found on the COBALT website.