Medicinal Cannabis and Anxiety, explained

Anxiety is an extremely prevalent mental health condition affecting millions of Australians daily. With symptoms ranging from excessive worry and restlessness to panic attacks and sleep disturbance, it’s no wonder so many Australians are turning to a wide range of therapies to help manage their condition.

Anxiety is among the top conditions that cannabis is prescribed to help treat in Australia.¹ In this article, we’ll break down why medicinal cannabis is becoming such a popular treatment for anxiety and how it can help reduce anxiety symptoms in some patients.

What is anxiety?

Anxiety is the body’s physical response to a real or perceived threat. Everyone experiences anxiety from time to time, it can even help us avoid danger in some real-life situations. But for some people, anxious feelings and symptoms don’t go away. They stick around even when there is no real or immediate threat to that person. Anxiety can affect concentration, sleep, relationships and the ability to carry out daily tasks. When anxiety is a problem that persists without the presence of a real or immediate threat, it is generally categorised as an anxiety disorder.

Anxiety disorders are the most common group of mental health conditions in Australia and affect 1 in 4 Australians² at some stage in their life.

The common types of anxiety disorders are:

• Generalised anxiety disorder
• Social phobia or social anxiety disorder
• Panic disorder
• Agoraphobia
• Specific phobias
• Obsessive compulsive disorder (OCD)
• Post-traumatic stress disorder (PTSD)

In some people, anxiety may also be linked to an underlying health issue. For some, this may mean anxiety signs and symptoms are the first indicators of a medical illness. Conditions associated with anxiety can include chronic pain, IBS, drug or alcohol dependence or withdrawal, thyroid problems, heart disease and diabetes. Certain medications can also cause anxiety in some people.

What are the symptoms of anxiety?

Some of the physical symptoms of anxiety can include:

• Panic attacks
• Shortness of breath
• Heart palpitations
• Dizziness
• Excessive sweating
• Sleep issues
• Stomach issues
• Lightheadedness 
• Dizziness
• Trembling
• + more

People who have anxiety may also avoid certain situations, such as crowds or social events, and may experience constant feelings of fear, racing thoughts, difficulty concentrating and memory disturbances.

Anxiety symptoms may also vary depending on the type of anxiety disorder someone has, for example:

• Generalised anxiety disorder may cause excessive worry about a range of issues such as health, work or finances.
• Social phobia or social anxiety disorder often causes people to avoid social or performance situations for fear of being embarrassed or rejected.
• Panic disorder can cause regular panic attacks, which are sudden intense episodes of irrational fear, shortness of breath, dizziness and other physical symptoms.
• Agoraphobia leads people to avoid certain situations due to fear of having a panic attack (often associated with panic disorder).
• Specific phobias will cause anxiety symptoms in one particular situation or context, such as a fear of animals, insects, places or people. 
• Obsessive compulsive disorder (OCD) causes unwanted thoughts and impulses, causing repetitive, routine behaviours as a way of coping with anxiety.
• Post-traumatic stress disorder (PTSD) leads to persistent feelings of fear or avoidance that do not fade after experiencing or witnessing a traumatic life event. PTSD symptoms can include upsetting memories, hypervigilance, flashbacks, nightmares and difficulties sleeping.

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How is anxiety typically treated?

Treatments for anxiety are dependent on the patient’s needs, as well as the type and severity of anxiety being experienced. Anxiety treatment may include psychological therapy, lifestyle changes (including sleep, nutrition and exercise), meditation and mindfulness and/or medication, or any combination of those treatments.

The Royal Australian & New Zealand College of Psychiatrists recommends cognitive behavioural therapy (CBT) as the first line treatment for generalised anxiety disorder, panic disorder and social anxiety disorder.¹⁴ Research shows that CBT is one of the most effective treatments for anxiety, and for preventing future anxiety.¹⁵ CBT treatment involves implementing strategies to change unhelpful thinking patterns and behaviours. It is generally conducted by a trained therapist over 6 sessions or more, and may be used alongside other therapy types, such as exposure therapy or interpersonal therapy.

Pharmacological treatments like antidepressants and tranquillisers are also commonly prescribed to treat symptoms of severe anxiety, panic and stress. For some, these medications can be extremely valuable and even life-saving. They can help patients go about their lives and participate in situations that their anxiety previously prevented. But for others, these treatments come with a wide range of unwanted side effects that make them intolerable. 

These can include:

Potential adverse side effects of antidepressants: 

• Sleep disturbance
• Changes in sexual function / desire
• Loss of full range of emotions
• Tremors
• Weight gain
• Constipation

‍Potential adverse side effects of long term use of tranquilisers

• Impaired learning
• Increased depression
• Memory loss
• Increased risk of dementia
• Increased risk of death (due to tranquiliser’s impact on respiratory drive in brainstem)

The range of negative side effects that standard pharmacological treatments for anxiety can elicit in some patients has led many to seek alternative medicines and options for treatment, from herbal solutions like kava, ashwagandha and lavender supplements to alternative prescriptions like medicinal cannabis.

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Can cannabis help treat anxiety?

Anxiety is the second most common condition³ that medicinal cannabis (sometimes referred to as ‘medical marijuana’, learn about the history and implications of this term here) is prescribed to treat in Australia. Both THC- and CBD-dominant cannabis treatments are prescribed to help treat symptoms of anxiety. A 2018–2019 survey⁴ of 1388 Australian respondents who were self-medicating with (mostly illicit) cannabis also found anxiety to be the most common ‘main condition’ being treated with cannabis. 

While there is conflicting information surrounding cannabis and anxiety, we know that many patients benefit from using medicinal cannabis to treat their anxiety and those that do maintain an ongoing medicinal cannabis treatment plan for anxiety do so because they prefer these treatments to standard or conventional treatments they have previously tried. 

For others, cannabis may not be an effective treatment for anxiety or it may even increase anxiety in some patients. It comes down to the individual, the type and severity of the anxiety, and the type of cannabis medication prescribed to that patient.

One rationale for the use of medicinal cannabis for treating anxiety symptoms stems from the way cannabis interacts with the body’s endocannabinoid system (ECS). The ECS is a biological system present in all humans (and nearly all animals) which regulates numerous physiological processes including mood, appetite, sleep, cognition and immune function. Our ECS and the physiological processes it regulates can be supported through a range of methods and lifestyle changes, including eating foods rich in omega-3 fatty acids, drinking less alcohol and consuming cannabinoids. Preclinical research5 also suggests that the phytocannabinoids found in cannabis (including THC and CBD) can support the production and release of endocannabinoids which may have efficacy in treating anxiety disorders. However more clinical research is required in this area. Learn more about your endocannabinoid system.

Does CBD help with anxiety?

CBD and CBD oil treatments may help manage the symptoms of anxiety in some patients. CBD has been shown to have anxiolytic (anxiety reducing) potential in numerous studies, including a 2015 review⁶ of 49 primary preclinical, clinical, or epidemiological studies supporting CBD as a treatment for generalised anxiety disorder, panic disorder, social anxiety disorder, obsessive-compulsive disorder, and post-traumatic stress disorder when administered acutely.

This study’s preclinical evidence conclusively demonstrated CBD’s efficacy in reducing anxiety behaviours relevant to the above anxiety disorders with a notable lack of anxiogenic (anxiety causing) effects. 

In 2022, the Cannabidiol Youth Anxiety Pilot Study⁷ conducted by Orygen also found that CBD may be effective in halving the severity of symptoms and impairment caused by chronic anxiety. The study involved 31 participants aged 12–25 who were recruited from Orygen’s primary care services. The participants had a diagnosed anxiety disorder and had failed to show significant improvement in anxiety severity following at least five cognitive behavioural therapy (CBT) sessions.

“Young people with treatment-resistant anxiety had an average 42.6 per cent reduction in anxiety severity and impairment following 12 weeks’ treatment with cannabidiol – a non-intoxicating component of the Cannabis sativa plant which is often referred to as CBD.”

– Orygen, 2022

Orygen’s pilot study found that CBD not only helped to reduce anxiety symptoms, but was also very well tolerated. They noted that they “did not see side-effects like suicidal thoughts, irritability or sleep problems, which are not uncommon in people taking SSRIs.”

CBD works to reduce anxiety in a number of ways. It can activate our serotonin receptors,⁸ modulate the potential anxiety-inducing effects of THC (thanks to the entourage effect) and reduce the fatty acid amide hydrolase enzyme⁹ that breaks down one of the body’s own important endocannabinoids – anandamide – which stimulates feelings of happiness and mental wellbeing. Anandamide deficiency has been shown to be a predictor of stress-induced anxiety, with decreased anandamide corresponding to increased anxiety-like behaviours.¹⁰ So CBD’s ability to prevent a decrease in anandamide levels makes it a promising treatment for anxiety disorders.

Like with any medication, the effects of CBD will vary depending on the individual and the dose taken.

Does THC help with anxiety?

Like CBD, THC has been shown to have the potential to treat anxiety, depending on the individual patient and the prescribed dosage. A 2019 analysis of 83 eligible studies¹¹ found that ‘pharmaceutical THC (with or without CBD) improved anxiety symptoms among individuals with other medical conditions (primarily chronic non-cancer pain and multiple sclerosis).’ While another 2019 review¹² of the evidence supporting the use of THC in PTSD found emerging evidence for positive effects on sleep, nightmares and global PTSD symptoms.

So while there is less evidence to support the use of THC-dominant formulations for anxiety disorders, there is stronger emerging evidence supporting its use in patients with PTSD, as well as anecdotal patient accounts of THC’s efficacy in treating anxiety symptoms.

Unlike CBD which works indirectly with the endocannabinoid system (ECS) and our cannabinoid receptors, THC acts directly upon the body’s ECS¹³ by stimulating our cannabinoid receptors (CB1 and CB2). Because the ECS is responsible for maintaining balance and harmony in the body, the effects of THC will be dose-dependent. Meaning the correct dose of THC can help create balance, while too much THC can cause an imbalance (and potentially increase anxiety). With the help of a prescribing cannabis doctor, therapeutic benefits for anxiety can be achieved by finding the right dose of THC for an individual patient.

It’s important to note that THC can exacerbate anxiety under some conditions and in some patients, and that there are driving restrictions for patients taking THC medications.

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Can terpenes in cannabis help with anxiety?

Terpenes are the organic, aromatic compounds found in plants in the form of oils. Essentially, they are what gives a plant its unique flavour and aroma. The cannabis plant alone contains more than 150 terpenes. But beyond just influencing the cannabis plant’s unique taste and smell, terpenes also play a significant role in the therapeutic effects of cannabis by interacting with cannabinoids and other cannabis compounds to create subtle differences in our experience.

On their own, there are a number of terpenes which can reduce anxiety, including linalool (found in lavender, rose and basil), limonene (found in lemon and citrus fruits), beta-caryophyllene (found in black pepper and cloves), myrcene (found in mango, thyme and lemongrass) and more. Each of these terpenes (and many more) can also be found in the cannabis plant. And by interacting with the range of cannabinoids and other compounds found within cannabis, terpenes can create or emphasise particular medicinal or other types of effects, opening up a world of therapeutic combinations for anxiety and many other conditions (again, thanks to the entourage effect).

Just like cannabinoids, your doctor can help you choose an appropriate cannabis treatment based on its terpene profile and the effects these terpenes may have on your specific symptoms or condition. So, if you’re interested in cannabis treatments for anxiety, we highly recommend talking to your doctor about which terpenes and medicinal cannabis formats might be best suited for you and your condition.

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Can cannabis cause or increase anxiety?

Now that we know medical cannabis has the potential to help treat anxiety in some patients, you might be wondering about some of the conflicting information you’ve seen around whether cannabis can actually cause or increase anxiety in some people.

The simple answer is: yes, cannabis has the potential to cause or increase anxiety in some patients, depending on the type and dose of cannabis administered. 

Let’s break this down into CBD and THC:

CBD → We know now that CBD is a known anxiolytic. Meaning it reduces anxiety with a lack of anxiogenic (anxiety causing) effects. CBD has a narrow side effect profile and does not cause the ‘high’ or any of the impairing effects that are typically associated with certain doses of THC. For these reasons, CBD is not a cannabinoid that is generally known to cause anxiety when taken at recommended doses (which all doctors will follow when prescribing cannabis treatments).

THC → THC is also commonly prescribed to treat anxiety disorders and has been shown to be effective for sleep, relaxation and PTSD. But because THC interacts so directly with the cannabinoid receptors within the endocannabinoid system, it has a stronger impact on the body’s ability to regulate anxiety and may even cause or increase anxiety when taken at too high a dose. With the help of a prescribing doctor, patients can mitigate these side effects by finding the correct product, strain and dose to achieve reduced anxiety levels through their medicinal cannabis treatment plan. But as with any medication or treatment plan, results will vary depending on the individual patient.  

What cannabis formats are best for anxiety?

Cannabis medicine is not a one-size-fits-all approach. This means most doctors will take a unique approach to treating each individual patient they see. Often, doctors will prescribe a combination of THC and CBD to help treat a patient with anxiety. But this will depend on individual factors such as the patient’s driving status and sensitivity to THC. 

Here are some examples of how doctors may prescribe cannabis to help treat anxiety:

Oral cannabis formats (oils, capsules, tablets, edibles): Often prescribed for ongoing anxiety and may contain just CBD or a combination of THC and CBD and other cannabis compounds such as terpenes. It’s common for doctors to prescribe a CBD only or high CBD cannabis treatment during the day to avoid impairment and then a THC/CBD treatment at night to support sleep – these are likely to be in an oil format. The effects of cannabis oils typically last longer than flower, about 6–8 hours.

Cannabis flower (for inhalation with a vaporiser): May also be prescribed for acute anxiety (such as panic attacks) due to rapid onset of effects. For individuals who are sensitive to THC, a high dose CBD flower may be prescribed. The effects of inhaled flower typically last shorter than oils, about 1–2 hours.

Exploring medical cannabis treatment options for anxiety

To be eligible for medicinal cannabis access as a patient in Australia, the TGA states that you must have a chronic medical condition (lasting 3 months or more) that conventional treatments have failed to treat and/or caused you unwanted side effects. Conventional treatments for anxiety may include any combination of psychological, pharmacological, lifestyle, herbal and other treatments that are commonly used to treat anxiety. So, if you have had chronic anxiety symptoms for 3 months or more and you are not satisfied with your current or past treatments, you may be eligible for medicinal cannabis access. 

If you are interested in exploring medical cannabis treatment options for anxiety, the first thing you’ll need to do is talk to a doctor. Our Polln practitioners are experts in medicinal cannabis who can help determine whether cannabis is a suitable treatment option for you, and which type of cannabis treatment might be right for the type of anxiety disorder you’re experiencing.

While cannabis is not a first line treatment in Australia, it is also not a last resort. Meaning you do not need to have exhausted all of your treatment options to be eligible for medicinal cannabis access. If you’re not sure whether you might be eligible, you can take our free eligibility quiz or sign up as a Polln patient to discuss your options with one of our expert doctors. 

Learn more about medicinal cannabis access in Australia.

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From the Doctor: Dr Amanda Steele, MChD

In Australia, anxiety is the second most common presentation for medicinal cannabis prescriptions³. Whenever a patient presents with symptoms of anxiety, I refer to the RANZCP Anxiety Clinical Practice Guidelines. The important questions I consider include:

• Is this anxiety? If so, how severe? 
• Is it an anxiety disorder?
• Are there comorbid disorders or differentials to consider?
• Does a referral to a psychiatrist and/or psychologist need to be considered?

If a patient presents with an anxiety disorder such as generalised anxiety disorder, social anxiety disorder, or panic disorder, Cognitive Behavioural Therapy (CBT) is the recommended first line treatment. If symptoms are severe, an assessment by a psychiatrist for diagnostic clarification and consideration of adjunct medications such as Selective Serotonin Reuptake Inhibitors (or SSRIs) to help the patient engage in CBT is recommended¹⁴. Although CBT +/- SSRIs help to achieve remission of anxiety for the majority of patients, a significant number of patients do not achieve remission of their anxiety³.

Currently as per the RANZCP guidelines, "There remains insufficient evidence to provide guidance on the use of cannabinoids for treating mental disorders within a regulatory framework."Recent meta analyses and systematic reviews looking at the therapeutic role of medicinal cannabis for mental health disorders have found that “the trial evidence to date is patchy, low quality and at high risk of bias”. There is some evidence to support the use of CBD to treat anxiety symptoms at certain doses, and the use of THC in treating PTSD symptoms.  However, there is insufficient evidence to support the use of THC for treating anxiety disorders with a risk of increasing anxiety due to the psychoactive effects³. Hopefully, as more quality research on using medicinal cannabis as treatment for mental disorders becomes available, clinical guidelines can be developed to provide clinicians a framework for prescribing more safely and effectively.

Anecdotally, some patients have reported benefits with CBD and THC products to help relieve their anxiety symptoms where evidence based modalities have been ineffective. Some patients have also reported an increase in anxiety symptoms with the use of CBD and THC products, in some cases this has been strain dependent.  Although medicinal cannabis has been a useful tool for anxiety symptoms as reported by some patients, it can also be used as an avoidance tool, which will likely make the anxiety symptoms worse with time if the underlying cause of the anxiety is not treated. As such, it is recommended that appropriate therapy, such as CBT for anxiety disorders, remains the mainstay of treatment. It is also important to note that medicinal cannabis does not replace current recommended pharmacological treatments for anxiety disorders e.g. SSRIs, especially if symptoms are severe or co-morbid diagnoses are present.  

Mental health conditions like anxiety can be complex diagnostically and therapeutically. Seeking advice from psychiatrists and psychologists can be extremely helpful for identifying the underlying source of the anxiety and ensuring appropriate evidenced based treatments have been considered.   

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