Medical Cannabis and Antidepressants: Can You Take Them Together?
Medical Cannabis and Antidepressants: Can You Take Them Together?
If you take an antidepressant such as sertraline, citalopram, fluoxetine or amitriptyline, you may be wondering whether it can be taken alongside medical cannabis.
Taking an antidepressant does not automatically mean that you cannot be prescribed medical cannabis. However, cannabinoids including THC and CBD can interact with some medicines, and certain effects — such as drowsiness, dizziness or changes in mood — may overlap.
That makes your current medication an important part of a medical cannabis assessment. A specialist clinician should review the medicines you take, your medical history and your individual risk factors before deciding whether treatment is appropriate.
In this guide, we look at medical cannabis and antidepressants, potential drug interactions, commonly prescribed antidepressants including sertraline and citalopram, and what patients should discuss with their clinician.
Contents
Can You Take Medical Cannabis With Antidepressants?
It may be possible to take prescribed medical cannabis alongside an antidepressant, but this should be assessed and monitored by a clinician.
There is no single interaction that applies to every antidepressant or every cannabis-based medicine. The potential for an interaction depends on factors including:
- The antidepressant you take
- Your antidepressant dose
- Whether a cannabis medicine contains THC, CBD or both
- The dose and formulation of the cannabis medicine
- Other prescription and non-prescription medicines you use
- Your physical and mental health history
This is why patients should not try to determine compatibility from an online interaction checker alone.
At CB1 Medical, current prescriptions form part of the clinical assessment, allowing potential interactions and suitability to be considered before medical cannabis is prescribed.
Why Can Medical Cannabis Interact With Other Medicines?
A drug interaction occurs when one substance changes the way another medicine works in the body.
One reason this can happen with cannabinoids involves a group of liver enzymes known as the cytochrome P450 or CYP450 system.
These enzymes help the body process many medicines. Cannabinoids, particularly CBD, can affect some of the same enzymes used to metabolise prescription drugs.
A 2024 systematic review of cannabinoid drug interactions found evidence that cannabinoids can alter the pharmacokinetics of certain medicines. The researchers highlighted shared CYP450 pathways as an important potential mechanism.
A more recent 2026 review of cannabinoid pharmacokinetic interactions also examined the way major cannabinoids interact with metabolic pathways used by medicines prescribed for conditions including depression and anxiety.
This does not mean that everyone taking medical cannabis will experience a drug interaction. It means that other medication needs to be considered when cannabinoids are prescribed.
THC, CBD and Antidepressants
Medical cannabis is not one single medicine. Different prescribed products can contain different amounts and ratios of tetrahydrocannabinol (THC) and cannabidiol (CBD).
THC and CBD also have different effects.
THC can be intoxicating and may cause effects such as dizziness, drowsiness, changes in concentration or changes in mood and perception.
CBD is not intoxicating, but it can affect enzymes involved in the metabolism of other medicines.
The UK’s Food Standards Agency advises that CBD can interact with certain medications and recommends that people taking medicines should not use consumer CBD products unless under medical direction.
Prescribed cannabis-based medicines are different from over-the-counter CBD wellness products, but the potential for interactions is one reason why cannabinoid treatment should be considered alongside a patient’s complete medication history.
Medical Cannabis and SSRIs
Selective serotonin reuptake inhibitors (SSRIs) are a widely prescribed group of antidepressants.
Examples include:
- Sertraline
- Citalopram
- Escitalopram
- Fluoxetine
- Paroxetine
SSRIs are not all metabolised in exactly the same way. This means the potential for a pharmacokinetic interaction with cannabinoids can vary between medicines.
There can also be overlapping effects. For example, depending on the individual medicine, antidepressants and cannabinoids may both contribute to symptoms such as dizziness, tiredness or changes in concentration.
For this reason, the name and dose of your SSRI should always be included when discussing medical cannabis and antidepressants with a clinician.
Medical Cannabis and Sertraline
Sertraline is an SSRI commonly prescribed for depression and several anxiety-related conditions.
Research suggests there is a potential interaction between CBD and sertraline because both can involve CYP450 metabolic pathways.
A 2024 review of drug-cannabinoid interactions identified sertraline among the antidepressants for which CBD may alter metabolism.
There are also published reports of adverse events involving cannabinoids alongside psychotropic medicines, including sertraline. However, these reports do not establish that every patient taking the combination will experience an interaction.
If you take sertraline, do not stop it because you are considering medical cannabis. Tell the prescribing clinician that you take sertraline, including your current dose, so they can assess the combination appropriately.
Medical Cannabis and Citalopram
Citalopram is another commonly prescribed SSRI, and this is an area where newer human evidence is particularly useful.
A 2026 clinical pharmacology study investigated CBD alongside citalopram in healthy adults.
After 12 days of CBD administration, researchers found that overall exposure to citalopram was higher when it was taken with CBD than when citalopram was taken alone.
This provides direct human evidence that CBD can affect citalopram pharmacokinetics under the conditions used in the study.
It does not mean that citalopram and prescribed medical cannabis can never be used together. It does mean that the combination deserves appropriate clinical consideration and monitoring.
Medical Cannabis and Fluoxetine
Fluoxetine — often known by the brand name Prozac — is another SSRI used in the treatment of depression and some other mental health conditions.
Fluoxetine is processed through liver enzyme pathways and can itself affect the metabolism of other medicines.
Cannabinoids can also influence CYP450 enzymes, creating the potential for pharmacokinetic interactions.
However, the amount of direct clinical evidence specifically examining prescribed cannabis alongside fluoxetine remains limited. Rather than assuming the combination is either safe or unsafe, patients should have their medication reviewed individually.
Medical Cannabis and SNRIs
Serotonin and noradrenaline reuptake inhibitors (SNRIs) are another group of antidepressants.
Common examples include:
- Duloxetine
- Venlafaxine
Duloxetine may also be prescribed for certain types of nerve pain, meaning some people exploring medical cannabis for chronic pain may already be taking it.
As with SSRIs, there is no universal rule that applies to every SNRI and every cannabis-based medicine. Potential metabolic interactions, overlapping side effects and the patient’s wider medication list all need to be considered.
If you take duloxetine or venlafaxine, include the medicine and dose when providing your medication history to a medical cannabis clinician.
Medical Cannabis and Amitriptyline
Amitriptyline is a tricyclic antidepressant. Although originally developed as an antidepressant, lower doses are also commonly used for certain chronic and neuropathic pain conditions.
This makes amitriptyline particularly relevant to patients considering medical cannabis for persistent pain.
Amitriptyline and cannabinoids can have overlapping effects such as drowsiness and dizziness. Amitriptyline is also metabolised through CYP450 pathways that cannabinoids may affect.
A published review of cannabinoid-drug interactions identifies amitriptyline as one of the antidepressants for which CBD could potentially affect metabolism and adverse effects.
Patients taking amitriptyline should therefore make sure their clinician knows the dose, why it has been prescribed and whether they take any other medicines that can cause sedation.
Medical Cannabis and Mirtazapine
Mirtazapine is an antidepressant that can cause sleepiness, particularly for some people when treatment begins.
Because some cannabis-based medicines can also cause drowsiness or dizziness, there is potential for overlapping effects.
Mirtazapine is also metabolised using enzyme pathways that may be affected by cannabinoids. Reviews of cannabinoid interactions therefore identify it as a medicine where an interaction is biologically plausible.
Again, this is not the same as saying that everyone taking mirtazapine is unsuitable for medical cannabis. It means the combination should be assessed rather than self-managed.
What Side Effects Should Patients Look Out For?
The effects experienced when combining medicines vary from person to person.
Depending on the antidepressant and prescribed cannabis medicine, clinicians may consider effects such as:
- Increased drowsiness or tiredness
- Dizziness or feeling light-headed
- Changes in concentration
- Changes in coordination
- Changes in mood or anxiety
- Gastrointestinal symptoms
THC-containing medicines can also be intoxicating and may worsen anxiety, paranoia or other psychiatric symptoms in some people. Mental health history is therefore an important part of assessing suitability.
You can read more about treatment safety in our guide to medical cannabis eligibility and suitability in the UK.
Should You Stop Taking Your Antidepressant?
No — you should not stop taking a prescribed antidepressant simply because you are considering medical cannabis.
Stopping some antidepressants suddenly can cause withdrawal symptoms and may cause the condition being treated to worsen.
Instead, continue taking your prescribed medication as directed and tell the medical cannabis clinician exactly what you take.
CB1 Medical’s patient information guidance advises patients to continue taking their existing medication as normal. If changes to other medication later become appropriate, they should be made gradually and with appropriate clinical guidance.
Medical cannabis should therefore not be viewed as a reason to independently stop, reduce or replace an antidepressant.
What Should You Tell Your Medical Cannabis Clinician?
Before a prescription is considered, give your clinician an accurate and up-to-date medication history.
That includes:
- Prescription antidepressants
- Other prescription medicines
- Over-the-counter medicines
- CBD products
- Vitamins and supplements
- Any recent medication changes
- Any side effects you currently experience
You should also discuss your mental health history openly. THC can affect mood, anxiety and perception, so previous or current psychiatric symptoms can influence whether a particular treatment is appropriate.
CB1 Medical considers current medication and medical history when assessing conditions that may be suitable for medical cannabis treatment.
Medical Cannabis and Antidepressants FAQs
Can You Take Medical Cannabis With Sertraline?
It may be possible for some patients, but sertraline and cannabinoids can involve overlapping metabolic pathways and side effects. If you take sertraline, tell your medical cannabis clinician the medication and dose so the potential interaction can be assessed before treatment is prescribed.
Can You Take Medical Cannabis With Citalopram?
Potential interactions need to be considered. A 2026 human study found that repeated CBD administration increased exposure to citalopram under the conditions tested. This does not automatically rule out treatment, but it provides a good reason for clinical assessment and monitoring.
Can You Take Medical Cannabis With Fluoxetine?
Fluoxetine and cannabinoids can both interact with liver enzymes involved in drug metabolism. Direct clinical evidence specifically examining the combination remains limited, so suitability should be assessed individually rather than assumed.
Can You Take Medical Cannabis With Duloxetine?
Taking duloxetine does not automatically make someone unsuitable for medical cannabis. However, the potential for drug interactions and overlapping effects should be considered by the prescribing clinician.
Can You Take Medical Cannabis With Amitriptyline?
Amitriptyline and cannabis-based medicines can both cause effects such as drowsiness and dizziness, while CBD may also affect enzymes involved in amitriptyline metabolism. A clinician should therefore review the combination before medical cannabis is prescribed.
Can You Take Medical Cannabis With Mirtazapine?
Potential overlapping effects include drowsiness and dizziness, and there are possible metabolic interactions. This does not mean the combination is automatically unsuitable, but it should be clinically assessed.
Does CBD Interact With Antidepressants?
CBD can inhibit some of the enzymes the body uses to metabolise medicines. The significance varies by drug and dose. Human research has demonstrated a pharmacokinetic interaction between CBD and citalopram, while laboratory, clinical and review evidence identifies potential interactions with several other antidepressants.
Does THC Interact With Antidepressants?
THC can contribute to effects such as dizziness, drowsiness and changes in mood, anxiety, perception or concentration, which may overlap with effects from some antidepressants. Cannabinoids may also be involved in pharmacokinetic drug interactions, so THC-containing treatment should be considered alongside a patient’s medication history.
Can Medical Cannabis Replace Antidepressants?
You should not stop or replace an antidepressant without medical guidance. If a clinician later believes changes to existing medication are appropriate, this should be planned and monitored rather than done independently.
Do I Need to Tell My Medical Cannabis Doctor About My Antidepressants?
Yes. Tell your clinician about all prescription medicines, over-the-counter medicines, supplements and CBD products you use. This allows potential interactions and overlapping side effects to be considered as part of your assessment.
The Bottom Line
Taking antidepressants does not automatically mean that medical cannabis is unsuitable for you.
However, cannabinoids can interact with some medicines through metabolic pathways, and antidepressants and cannabis-based medicines can sometimes have overlapping effects.
Research is also still developing. We have direct human evidence for some combinations, such as CBD and citalopram, while evidence for many other individual antidepressants remains much more limited.
That is why medical cannabis and antidepressants should be considered on an individual basis by a clinician who can review your medication, medical history and treatment needs.
Considering Medical Cannabis?
Medical cannabis has been legally available on prescription in the UK since 2018. It is not suitable for everyone, and treatment requires an individual clinical assessment.
At CB1 Medical, your current medication and medical history are reviewed as part of the assessment process so that suitability and potential interactions can be considered before treatment is prescribed.
If you have tried at least two conventional treatments for your condition, you can check your eligibility online to see whether you may be suitable for a consultation.
