Active not recruitingPHASE2INTERVENTIONAL

Cannabis (THC vs. CBD) in Multiple Sclerosis

This research aims to understand how two different components found in cannabis, THC and CBD, affect people living with Multiple Sclerosis (MS). Specifically, it will look at their impact on memory, thinking skills, and bladder issues. MS is a long-term condition affecting the brain and spinal cord, and bladder problems are a common symptom. We know that some people with MS use cannabis, but there's a need to understand its effects better, especially on thinking abilities, which MS can already affect. Participants will be randomly given either THC or CBD oil to take for 15 weeks, and their progress will be monitored through questionnaires and memory tests.

At a glance

Status

Active not recruiting

Phase

PHASE2

Sponsor

University of Calgary

Enrolment target

Start

05 Dec 2025

Estimated completion

01 Sep 2026

Multiple Sclerosis

What is this study about?

This study is designed to explore how two specific substances found in cannabis, called THC and CBD, might affect people who have Multiple Sclerosis (MS). MS is a condition that impacts your brain and spinal cord, and it can cause a range of symptoms, including difficulties with memory and thinking, as well as problems with bladder control. Many people with MS already use cannabis or cannabis-based products, hoping for some relief, but we don't fully understand how it affects them, especially their thinking abilities.

The main goal of this trial is to compare the effects of THC and CBD on memory, thinking skills, and bladder symptoms in people with MS. We want to see if one has different effects than the other, particularly regarding thinking, which can sometimes get worse with cannabis use, and is already a challenge for many people with MS. Understanding these differences is really important because it can help doctors and patients make better choices about using cannabis-based treatments.

By taking part in this study, you would help researchers gather vital information. This information will not only help people with MS manage their symptoms but also provide clearer guidance on the potential benefits and risks of using different cannabis components. The findings could lead to safer and more effective ways for people with MS to manage their condition.

Key takeaways

This study compares THC and CBD in people with MS.
It focuses on memory, thinking skills, and bladder issues.
Participants will take either THC or CBD oil for 15 weeks.
The study aims to provide clearer guidance on cannabis use for MS.
You'll undergo questionnaires and cognitive (thinking) tests.
It's a 'double-blind' study, meaning you won't know which oil you're taking.

Who may be eligible?

To be considered for this study, you need to be between 18 and 59 years old and have a confirmed diagnosis of Multiple Sclerosis. You should also be experiencing bladder problems linked to your MS. If you’re already taking medication for your bladder issues, you need to have been on a steady dose for at least four weeks.

There are also some important things that would prevent you from joining. For example, if you have a major mental health condition like schizophrenia or bipolar disorder, or if you have another serious brain condition like dementia or a history of severe head injury. You also can't participate if you have seizures, take certain antipsychotic medicines, or regularly use benzodiazepines (unless it's just for sleep).

You can't join if you've had an MS relapse in the last three months, or if you currently use cannabis more than three times a week. If you use cannabis less often but aren't willing to stop during the study, you also won't be able to take part. Other reasons include very poor eyesight, severe arm or hand disability that would make it hard to do tests, having a permanent bladder tube (catheter), or if you are pregnant or breastfeeding.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you between 18 and 59 years old?
Do you have a diagnosis of Multiple Sclerosis?
Are you experiencing bladder problems due to MS?
Have you *not* had an MS relapse in the last 3 months?
Do you use cannabis less than 3 times a week, and are you willing to stop during the study?
Are you *not* pregnant or breastfeeding?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, you'll first complete some questionnaires and tests that check your memory and thinking skills. After that, you'll be randomly assigned to receive either a THC oil or a CBD oil. This means you won't get to choose which one you receive. You'll take this study oil every day for 15 weeks. Throughout these 15 weeks, you'll have regular check-ups where you'll answer more questions about your symptoms and repeat the memory and thinking tests. The research team will guide you through each step and explain everything in detail. The total duration of your active participation, including all tests and taking the study oil, will be about 15 weeks.

Potential risks and benefits

Taking part in this study could offer several potential benefits. You might gain a better understanding of how cannabis components affect your MS symptoms, particularly regarding bladder control and cognitive function. However, there are also potential risks to consider. While THC and CBD are generally well-tolerated, they can cause side effects. For instance, THC can sometimes affect thinking and mood, and both can interact with other medications. It's important to remember that you are free to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (1)

University of Calgary
Verified postcode
Calgary, Canada

Common questions

What is the main purpose of this study?

The study aims to compare how THC and CBD, two parts of cannabis, affect memory, thinking, and bladder problems in people with Multiple Sclerosis (MS).

Will I know if I'm getting THC or CBD?

No, you will be randomly assigned to receive either THC or CBD oil, and neither you nor the researchers will know which one you are taking until after the study is over. This is called a 'double-blind' study.

How long will I be taking the study oil?

You will take the assigned study oil every day for 15 weeks.

What kind of tests will I have?

You will complete questionnaires about your symptoms and take tests to check your memory and thinking skills.

Can I continue my other MS medications?

You should discuss all your current medications with the study team. If you are taking medication for your bladder, it needs to have been stable for at least 4 weeks before joining.