Prescribed THC and ADHD

At Bluewater Health, patient safety and evidence-based practice are the foundation of all prescribing decisions.

This policy outlines our position regarding the use of cannabis products containing tetrahydrocannabinol (THC) in patients prescribed, or seeking prescription of, stimulant medications for Attention-Deficit/Hyperactivity Disorder (ADHD).

Clinical Rationale

Stimulant medications are prescribed to improve executive functioning, focus, and emotional regulation. The concurrent use of THC directly interferes with these therapeutic goals and introduces significant psychiatric and neurological risks.

Current clinical evidence demonstrates that combining these substances compromises both the safety and the effectiveness of ADHD treatment.

Identified Risks

The combined use of THC and stimulant medications is contraindicated at this clinic due to the following evidence-based risks:

Counteractive Effects: THC impairs attention, working memory, and processing speed. This directly negates the intended cognitive benefits of stimulant therapy.
Psychosis Risk: Both substance classes increase dopaminergic activity. Concurrent use significantly elevates the risk of acute psychosis, paranoia, and thought disorders.
Seizure Threshold: Combined use may lower the seizure threshold, introducing risk even in individuals with no prior history of epilepsy.
Cardiovascular & Autonomic Strain: Concurrent use increases the likelihood of tachycardia (rapid heart rate), hypertension (high blood pressure), and anxiety.

Prescribing Policy

Our policy is divided into two categories based on the type of medication being considered.

1. Stimulant Medications (Schedule 8)

Examples include: Ritalin, Concerta, Vyvanse, Dexamphetamine.

Due to the safety risks outlined above, our policy regarding stimulants is strictly enforced:

No Co-Prescribing: Bluewater Health does not prescribe stimulant medications to patients who are currently using cannabis products containing THC, regardless of whether the THC is prescribed or illicit.
Initiation of Care: Stimulant medications will not be initiated until abstinence from THC is confirmed.
Driving & Legal Safety: Both THC and stimulants have implications for driving legality and insurance. The combination presents an unacceptable legal and safety risk for both the patient and the community.

2. Non-Stimulant Alternatives

Examples: Atomoxetine (Strattera), Guanfacine (Intuniv), Clonidine.

For patients unwilling or unable to cease THC use, non-stimulant medications offer an alternative treatment pathway.

A Case-by-Case Approach: Unlike stimulants, these medications are not strictly contraindicated with THC. We are open to discussing and potentially prescribing these options based on individual assessment.
Impact on Effectiveness: It is important to note that while the safety risks are lower, concurrent THC use may still reduce the overall effectiveness of non-stimulant medications.

Cessation and Verification (For Stimulant Pathways)

For patients wishing to commence a trial of stimulant medication, the following steps are required:

Requirement: Cessation of all THC use is a prerequisite for any stimulant trial.
Verification: Abstinence must be confirmed via Urine Drug Screening (UDS) ordered by the clinic.
Washout Period: Patients should be aware that chronic THC use may result in positive UDS results for several weeks after stopping use. A confirmed negative result is required before stimulants can be commenced.

Coordination of Care

If a patient elects to continue using THC and declines or is unsuitable for non-stimulant alternatives, Bluewater Health cannot safely proceed with ADHD management.

In these instances, the patient’s care will need to be coordinated by their General Practitioner or their THC-prescribing clinician.

Note on CBD-Only Products
This policy does not apply to CBD-only products.
Patients using CBD isolates or broad-spectrum products confirmed to contain 0% THC remain eligible for stimulant treatment, as these products do not carry the same documented risks regarding psychosis or cognitive impairment in combination with stimulants.

Support for Reducing or Stoping THC

Bluewater Health recognises that some patients wish to reduce or stop using THC-containing cannabis products, regardless of the original reason for use or prescribing pathway. Support is available.

Patients seeking help to reduce or cease THC use are welcome to discuss this with their treating psychiatrist at Bluewater Health, who can provide clinical guidance, brief intervention, and support with planning a safe and supported reduction or cessation. Where appropriate, care can be coordinated with the original prescriber or the patient’s GP.

Additional support options include:

Referral via your GP to local alcohol and other drug (AOD) services
Self-referral to specialist services, such as Cyrenian House, which provides confidential counselling and treatment programs for cannabis and other substance use
- Website: https://www.cyrenianhouse.com

Seeking support to reduce or stop THC use does not require a specific diagnosis or referral reason and does not preclude future psychiatric care. Patients are encouraged to seek help early if THC use is causing concern, side effects, or functional impairment.