The Dangers of Stimulants and THC

The Dangers of Stimulants and THC.
Medicinal cannabis and stimulant medications are both used to treat ADHD and other neurodiverse conditions in Australia. When taken together, they potentially pose significant health implications.
Impact of Stimulants
Stimulant medications increase the production of dopamine and other neurotransmitters in the brain. The outcome of these increased chemicals improves focus, memory, motivation, and thinking speed. More information can be found here.
Impact of THC:
THC (the active ingredient in cannabis) activates cannabinoid receptors and increases dopamine too, causing the “high” feeling.
THC can also disrupt memory, reduce motivation, and impair thinking and decision-making. A report by Harvard Medical School outlines the effects of THCon the brain and body.
The Problem
When both medications are taken together the potential of negative implications may develop including,
- Severe anxiety or panic attacks
- Paranoia or psychotic symptoms (hallucinations, delusions)
- Poor judgment and risky behaviour
- Addiction potential
- Uncontrollable mood swings
The brain’s dopamine system can handle one psychoactive medication, but two at the same time creates unpredictable and dangerous effects.
Stimulants and Your Heart
Stimulant medications increase:
- Heart rate and blood pressure, often raising your normal heart rate and resting heart rate
- Your body’s stress response
- The effort required to keep blood flowing to your organs, which increases workload on the heart muscle
For most healthy people, this is safe in the short term. Your heart can handle these changes when you’re only taking one medication.
Cannabis and Your Heart
It can cause:
- Increased heart rate
- Dizziness when standing up
- High blood pressure
- Increased heart strain and changes in blood flowing through the coronary arteries
Regular cannabis use in people with existing cardiac risk factors or a known heart condition can increase the risk of heart attack or cardiac arrest, especially when combined with stimulant medications.
When You Take Both Together
Higher strain is placed on the heart leading to:
- Heart palpitations (feeling your heart skip or race)
- Dangerous blood pressure spikes and abnormal heart rate and blood pressure patterns
- Irregular heartbeats, including atrial fibrillation in people with structural heart disease
- Fainting
- Chest pain
- In rare cases, heart attack and life-threatening cardiac arrest
People at highest risk include those with:
- Existing heart conditions such as coronary heart disease, atrial fibrillation, or other structural heart disease
- Anxiety disorders
- High baseline or elevated resting heart rate
- Family history of heart problems or premature heart attack
Major organisations, including the National Heart Foundation of Australia and leading cardiology groups in the United States, highlight stimulant medications, cannabis use, and other cardiac risk factors as important issues to discuss with anyone who has a heart condition or is at increased risk of heart attack.

Your thinking Gets Worse, Not Better
One of the biggest problems with combining these medications is that cannabis can prevent the effectiveness of stimulant medications.
Cannabis Cancels Out Stimulant Benefits
Stimulants are prescribed to improve:
- Attention and focus
- Working memory
- Processing speed
- Executive function (planning and organization)
If you’re taking a stimulant for better focus and then use cannabis, you are offsetting the positive effects of the stimulant. Additionally this article provides more information on the useof Medical THC in ADHD populations.
Greater Likelihood of further problems
Combined use also increases psychiatric problems:
- Mood instability/ irritability
- Paranoia and suspicion
- Anxiety and panic
- Feeling disconnected from reality
- Psychosis (seeing or hearing things that aren’t there)
What the Law Says in Australia
Both stimulants and medicinal cannabis are Schedule 8 (S8)controlled medicines. This means they have strict rules around prescribing and monitoring.
Why This Matters
When a doctor prescribes both S8 drugs together, it triggers:
- Automatic flagging and prescription monitoring systems
- Increased government oversight and audits
- Requirement to document why both drugs are necessary
- Extra scrutiny from health departments
Legal Responsibility for Doctors
If a patient experiences problems while on both medications—such as psychosis, heart problems, or dangerous driving—the doctor can be held legally responsible.
In practice, most Australian doctors consider it impossible to justify co-prescribing these medications because the risks are well-known and documented.

Clear Clinic Policies
Dokotela will only allow suitable patients to be prescribed stimulants when medicinal THC is not present within a patient’s treatment plan.
This approach protects patients by:
- Maximising the likelihood that stimulants are an effective treatment
- Reducing heart and mental health risks
- Avoiding dangerous drug interactions
- Keeping your care within legal guidelines
The Bottom Line
Don’t mix stimulants and medicinal cannabis.
Both treatments have real benefits when used alone. Stimulants are effective for ADHD. Cannabis can help with certain conditions like Tourette syndrome or severe behavioural problems.
Where to Get Help
For more information:
- Talk to your GP or psychiatrist about your treatment options
- Ask your clinic about their prescribing policies
- Contact Beyond Blue or Headspace if you have concerns about medications or mental health
Further Information
RACGP medicinal cannabis safety guide
https://www1.racgp.org.au/ajgp/2021/june/a-primer-on-medicinal-cannabis-safety-and-potentia
AHA cannabis cardiovascular warning
https://www.ahajournals.org/doi/10.1161/CIR.0000000000000883
UK cannabis ADHD registry data
https://onlinelibrary.wiley.com/doi/10.1002/npr2.12400
.png)
Integrated Care for Co-occurring Addiction and Mental Illness
Integrated Care for Co-occurring Addiction and Mental IllnessIntegrated Care for Co-occurring Addiction and Mental Illness
Integrated Care for Co-occurring Addiction and Mental Illness.png)

