Anxiety disorders are among the most common mental health conditions presenting in Australian clinical practice, affecting approximately 1 in 5 Australians at some point in their lives.²

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Anxiety is among the most common conditions for which medicinal cannabis is prescribed in Australia,¹ and a range of pharmacological and non-pharmacological treatments are used to manage the condition. This article outlines the evidence base for medicinal cannabis in anxiety, the roles of CBD and THC, and practical prescribing considerations.

What is anxiety?

Anxiety disorders are characterised by excessive, persistent fear or worry that is disproportionate to the triggering stimulus and causes clinically significant distress or functional impairment. They represent the most common group of mental health conditions in Australia.

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Common anxiety disorder subtypes include:

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

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Anxiety may also be secondary to underlying medical conditions including chronic pain, irritable bowel syndrome, thyroid dysfunction, cardiovascular disease, diabetes, and substance use or withdrawal. Certain medications may also precipitate or exacerbate anxiety symptoms.

How is anxiety typically treated?

Treatment selection should be guided by the individual patient’s presentation, anxiety subtype, and symptom severity. The Royal Australian and New Zealand College of Psychiatrists (RANZCP) recommends cognitive behavioural therapy (CBT) as the first-line treatment for generalised anxiety disorder, panic disorder, and social anxiety disorder.¹⁴ CBT has a strong evidence base for reducing anxiety symptoms and preventing relapse,¹⁵ and is typically delivered by a trained therapist over six or more sessions, sometimes in combination with exposure therapy or interpersonal therapy.

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Pharmacological options, including antidepressants and anxiolytics, are commonly prescribed for moderate to severe anxiety and can provide significant symptomatic relief and functional improvement for many patients. However, these treatments carry a range of potential adverse effects that may limit tolerability in some patients.

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Potential adverse effects of antidepressants include:
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• Sleep disturbance
• Changes in sexual function or libido
• Emotional blunting
• Tremors
• Weight gain
• Constipation

Potential adverse effects of long-term anxiolytic (tranquilliser) use include:
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• Impaired learning and memory
• Increased depression
• Increased risk of dementia
• Increased risk of death due to respiratory depression

Where standard pharmacological treatments are poorly tolerated or insufficiently effective, patients may seek alternative therapeutic options, including herbal preparations and medicinal cannabis.

Can cannabis help treat anxiety?

Anxiety is among the most common conditions for which medicinal cannabis is prescribed in Australia.^1,3 Both THC- and CBD-dominant formulations are used in clinical practice for anxiety management. A 2018–2019 survey of 1,388 Australians self-medicating with cannabis also identified anxiety as the most commonly cited primary condition being treated.⁴

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The evidence base for medicinal cannabis in anxiety disorders is emerging but not yet definitive. Many patients report clinical benefit and sustained engagement with cannabis-based treatment, often citing preference over previously trialled conventional therapies. For others, cannabis may be ineffective or may exacerbate anxiety. Outcomes depend on the individual patient, anxiety subtype, and the specific formulation and dose prescribed.

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One mechanistic rationale for cannabis use in anxiety relates to its interaction with the endocannabinoid system (ECS) — a biological regulatory system present in all humans that modulates mood, appetite, sleep, cognition, and immune function. Preclinical research suggests that phytocannabinoids including THC and CBD may support endocannabinoid tone in ways that are relevant to anxiety pathophysiology.⁵ However, further clinical research is required to substantiate these findings.

Does CBD help with anxiety?

CBD has demonstrated anxiolytic potential across multiple study types. A 2015 review of 49 preclinical, clinical, and epidemiological studies supported CBD as a treatment for generalised anxiety disorder, panic disorder, social anxiety disorder, OCD, and PTSD when administered acutely — with preclinical evidence demonstrating reductions in anxiety-relevant behaviours and a notable absence of anxiogenic effects.⁶

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A 2022 open-label pilot study (n=31, aged 12–25) conducted by Orygen found that participants with treatment-resistant anxiety disorders — who had not responded to at least five CBT sessions — experienced a mean 42.6% reduction in anxiety severity and impairment following 12 weeks of CBD treatment. The authors noted a favourable tolerability profile, with no observed increase in suicidal ideation, irritability, or sleep disturbance. It should be noted that the open-label, uncontrolled design limits the generalisability of these findings.⁷

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Proposed mechanisms of CBD’s anxiolytic action include activation of serotonin (5-HT1A) receptors,⁸ modulation of THC’s potential anxiogenic effects via the entourage effect, and inhibition of fatty acid amide hydrolase (FAAH) — the enzyme responsible for degrading anandamide.⁹ Anandamide deficiency has been associated with stress-induced anxiety, with reduced anandamide levels correlating with increased anxiety-like behaviour in some patients.¹⁰ CBD’s capacity to preserve anandamide availability therefore represents a plausible therapeutic mechanism in anxiety disorders.

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As with any medication, the clinical effects of CBD will vary depending on the individual patient and the dose administered.

Does THC help with anxiety?

THC has demonstrated potential benefit for anxiety in specific populations. A 2019 systematic review and meta-analysis found that pharmaceutical THC (with or without CBD) improved anxiety symptoms in patients with comorbid medical conditions, primarily chronic non-cancer pain and multiple sclerosis.¹¹ A separate 2019 review identified emerging evidence supporting THC use in PTSD, with positive signals for sleep quality, nightmare frequency, and global PTSD symptom burden.¹²

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Unlike CBD, which acts indirectly on the ECS, THC acts directly on CB1 and CB2 receptors,¹³ producing dose-dependent effects. At appropriate doses, THC may support ECS homeostasis and reduce anxiety; at higher doses, it may precipitate or exacerbate anxiety in susceptible patients. Careful dose titration is therefore essential when prescribing THC-containing formulations for anxiety.

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Clinicians should also note that THC-containing medications carry driving restrictions under Australian law, which must be communicated to patients prior to prescribing.

Can terpenes in cannabis help with anxiety?

The terpene profile of a cannabis formulation may contribute to its anxiolytic potential through the entourage effect — the synergistic interaction between cannabinoids, terpenes, and other phytochemicals that can modulate overall therapeutic effect. Several terpenes found in cannabis have demonstrated anxiolytic properties in preclinical research, including linalool (also found in lavender), limonene (citrus), beta-caryophyllene (black pepper and cloves), and myrcene (mango and lemongrass).

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Terpene profile is a clinically relevant consideration when selecting a medicinal cannabis formulation for patients with anxiety, and may contribute to meaningful differences in treatment response between products.

Can cannabis cause or increase anxiety?

Cannabis has the potential to cause or exacerbate anxiety in some patients, depending on formulation and dose.

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CBD is a known anxiolytic with a narrow side-effect profile and no intoxicating effects. It does not typically produce anxiety at recommended doses and has not demonstrated anxiogenic effects in the reviewed literature.

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THC, while therapeutically useful for anxiety in appropriate doses, acts directly on cannabinoid receptors and has a stronger modulatory effect on the ECS. At excessive doses, THC may cause or worsen anxiety in some patients. Identifying the correct formulation, dose, and titration schedule for each individual is key to minimising this risk.

Prescribing formats for anxiety

Given the individual variability in response to medicinal cannabis, treatment should be tailored to each patient’s clinical profile. Format selection will depend on symptom type, severity, and whether the goal is acute or ongoing management.

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Oral formats (oils, capsules, tablets, pastilles)

Commonly prescribed for ongoing anxiety management. May contain CBD only, or a combination of THC, CBD, and other cannabinoids and terpenes. A common approach is to prescribe a CBD-dominant formulation during the day to minimise impairment, with a THC/CBD combination at night to support sleep. Duration of effect is typically 6–8 hours.

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Inhaled formats (dried herb, oil cartridges, metered dose inhalers)

May be appropriate for acute anxiety presentations, including panic attacks, due to rapid onset of action. For patients with THC sensitivity, high-CBD inhaled formulations may be preferable. Duration of effect is typically 1–2 hours.

Clinical considerations

Medicinal cannabis is not a first-line treatment for anxiety in Australia, but eligibility does not require exhaustion of all prior treatment options. It may be considered as part of a broader, individualised treatment plan.

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Given the diagnostic and therapeutic complexity of anxiety disorders, concurrent referral to a psychiatrist or psychologist is recommended where appropriate, to address underlying drivers of anxiety and support holistic patient management.

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