There are a number of inclusion and exclusion criteria that will help the research team decide whether it is safe for a patient to take part in the COBALT Trial. We have listed some of these below to give an idea of who might be able to take part. Only the trial doctors can make sure that a patient is able to take part in COBALT.

Inclusion criteria (answers must be yes to take part):

• Patients with a diagnosis of probable DLB or probable PDD.
• Aged ≥55.
• Taking a cholinesterase inhibitor for at least 12 weeks
• Sufficient knowledge of the English language or support to understand the Patient Information Sheet and complete the trial assessments

Exclusion criteria – (answers must be no to be able to take part)

• Chronic renal disease stage 5
• History of acute or chronic pancreatitis
• Epilepsy or former history of convulsions
• History of Heart attack withing the last 6 months
• Untreated Hypertension
• Severe liver impairment
• Kidney Impairment Patients taking Memantine, amantadine, ketamine, or dextromethorphan
• Patients without a Study partner who is willing to also take part and answer questions.