The two active compounds in your medicine

THC

Tetrahydrocannabinol

THC is the compound that can produce the 'high' feeling. It also acts on the brain's mood-regulation centres — but dose matters. At low, medically prescribed doses, THC may provide meaningful short-term relief from anxiety and low mood.^3,4

Activates CB1 receptors in areas of the brain that regulate stress, fear, and emotional memory³
At low doses may reduce anxious thoughts and improve mood by modulating dopamine release⁴
Can help break the cycle of intrusive thoughts linked to anxiety disorders and PTSD⁵
Particularly useful when anxiety is accompanied by pain or sleep disruption⁶
Important: High doses of THC can worsen anxiety — always start low and go slow⁴

CBD

Cannabidiol

CBD will not make you feel 'high'. Instead, it gently interacts with serotonin receptors (5-HT1A) and reduces the nervous system's overactivity — making it a promising option for anxiety, and potentially for low mood.^7,8

Acts on 5-HT1A (serotonin) receptors — the same pathway targeted by many antidepressants⁸
A 2024 meta-analysis of RCTs found CBD had a substantial effect on anxiety (Hedges' g = −0.92)⁷
May promote neurogenesis and reduce neuroinflammation — both linked to depression⁹
Can counterbalance THC-related anxiety, reducing unwanted side effects when both are used together⁶
CBD alone did not show anxiolytic effect in all studies — CBD in combination with trace THC (full-spectrum) appears more effective than isolate¹⁰

How does cannabis work for anxiety & depression?

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Your Body's Own System

Your body has a built-in endocannabinoid system (ECS) that regulates mood, stress response, memory, and emotional processing. In people with depression and anxiety, ECS signalling is often reduced. THC and CBD interact with the same CB1 and CB2 receptors used by your natural endocannabinoids — helping restore balance.^3,9

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Serotonin & Dopamine Pathways

CBD partially activates the 5-HT1A serotonin receptor — the same receptor targeted by SSRIs and buspirone. THC modulates dopamine release in the brain's reward circuits. Together, these actions may lift mood and reduce the over-active fear responses typical of anxiety disorders.^7,8

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Reducing Neuroinflammation

Growing evidence links both anxiety and depression to elevated neuroinflammation. CBD has demonstrated anti-inflammatory properties and may promote neurogenesis (growth of new brain cells) in the hippocampus — a region strongly associated with mood regulation and resilience.^9,11

When to take it & how much to start with

THC — Suggested Starting Ranges

Anxiety (new to cannabis) 1–2.5 mg

Anxiety (some experience) 2.5–5 mg

Depression / low mood 2.5–5 mg

When using alongside CBD 1:1 or 1:2 ratio

Best timing (oils/capsules) Evening, 60–90 min after dinner

CBD — Suggested Starting Ranges

Anxiety (gentle daily use) 15–25 mg

Anxiety (moderate-severe) 25–75 mg

Depression / mood support 25–50 mg

Full-spectrum sublingual oil 30 mg/day (split doses)¹⁰

Best timing Morning & evening, under tongue

Start low, go slow. Always begin at the lowest suggested dose and allow at least one week before increasing. THC's effects on anxiety are strongly dose-dependent — what relieves anxiety at a low dose may worsen it at a higher dose. Your MedWest pharmacist will guide you through this process at your own pace.

What a typical treatment journey may look like

Week 1–2

Starting out — finding your dose

Begin with the lowest dose of CBD and/or THC as prescribed. You may notice mild relaxation or improved sleep first. Anxiety relief may take several days to become apparent. Keep notes on how you feel — this helps your pharmacist adjust your regimen.

Week 2–4

Early effects — anxiety and mood

Many patients report reduced daily anxiety within two to four weeks of consistent use. You may notice you feel less reactive to stressors, sleep more soundly, and experience fewer intrusive or ruminative thoughts. Some mood improvement may become noticeable around this stage.^7,10

Month 1–3

Stable use — monitoring & adjusting

If your current dose is effective and well-tolerated, stay with it. If you feel the effects have reduced, speak with your pharmacist before increasing — gradual dose adjustments are always preferred. Your prescriber may review your treatment at this stage.

Ongoing

Long-term — important things to know

Research on long-term effects of medicinal cannabis for anxiety and depression is still emerging. Current evidence supports short-to-medium term benefit.^4,11 Medicinal cannabis is best used as part of a broader care plan — alongside psychological support, lifestyle measures, and your existing treatments where relevant.

Please read — important safety information

⚠ Before You Start

Medicinal cannabis is not a cure for anxiety or depression and should not replace established treatments without discussion with your doctor or psychiatrist. It may offer meaningful symptom relief — particularly when other treatments have been only partially effective.

THC and anxiety: THC effects are strongly dose-dependent. Low doses may reduce anxiety; higher doses can cause or worsen it. If you ever feel more anxious after taking your medicine, contact your MedWest pharmacist before adjusting your dose.

Not suitable for everyone: Medicinal cannabis is not recommended for people under 25 years of age, during pregnancy or breastfeeding, or for those with a personal or family history of psychosis, schizophrenia, or bipolar disorder with psychotic features.

Driving: Do not drive or operate heavy machinery after taking THC-containing products. Zero-tolerance drug driving laws apply in Western Australia regardless of prescription status.

Drug interactions: Cannabinoids can interact with antidepressants (including SSRIs and SNRIs), benzodiazepines, and other CNS-active medications. Always inform your prescriber of all medicines you are taking.

Questions to ask your MedWest pharmacist

What ratio of THC to CBD is right for anxiety versus depression?

Will this interact with my current antidepressant or anti-anxiety medication?

How do I know if my dose is working — what should I be noticing?

Should I take this in the morning, evening, or both?

Is a full-spectrum product better than CBD isolate for my situation?

What do I do if I feel more anxious after taking it?

Speak with your MedWest pharmacist today

Shop 17, 478 Wanneroo Road, Westminster WA 6061

📞 (08) 6256 1512

scripts@medwestmedical.com.au

Where this information comes from

The information in this guide is based on peer-reviewed research cited below. References are provided for transparency — you do not need to read them, but they are here if you would like to learn more.

1.World Health Organization. Mental disorders [Internet]. Geneva: WHO; 2022 [cited 2025]. Available from: https://www.who.int/news-room/fact-sheets/detail/mental-disorders
2.Fava M. Diagnosis and definition of treatment-resistant depression. Biol Psychiatry. 2003;53(8):649–59. doi: 10.1016/s0006-3223(03)00231-2
3.Morena M, Patel S, Bains JS, Hill MN. Neurobiological interactions between stress and the endocannabinoid system. Neuropsychopharmacology. 2016;41(1):80–102. doi: 10.1038/npp.2015.166
4.Turna J, Syan SK, Frey BN, Rush B, Costello MJ, Weiss M, et al. Cannabidiol as a novel candidate alcohol use disorder pharmacotherapy: a systematic review. Alcohol Clin Exp Res. 2019;43(4):550–63. Cited in: Turna J, MacKillop J, Quilty LC, et al. Cannabidiol as an intervention for addictive behaviors: A systematic review of the evidence. Subst Abuse. 2019;13. doi: 10.1177/1178221819845940
5.de Aquino JP, Sherif M, Radhakrishnan R, Cahill JD, Ranganathan M, D'Souza DC. The psychiatric consequences of cannabinoids. Clin Ther. 2018;40(9):1448–56. doi: 10.1016/j.clinthera.2018.06.019
6.Ferber SG, Namdar D, Hen-Shoval D, Eger G, Koltai H, Shoval G, et al. The 'entourage effect': terpenes coupled with cannabinoids for the treatment of mood disorders and anxiety disorders. Curr Neuropharmacol. 2020;18(2):87–96. doi: 10.2174/1570159X17666190903103923
7.Han K, Wang JY, Wang PY, Peng YCH. Therapeutic potential of cannabidiol (CBD) in anxiety disorders: a systematic review and meta-analysis. Psychiatry Res. 2024;339:116049. doi: 10.1016/j.psychres.2024.116049
8.García-Gutiérrez MS, Navarrete F, Gasparyan A, Austrich-Olivares A, Sala F, Manzanares J. Cannabidiol: a potential new alternative for the treatment of anxiety, depression, and psychotic disorders. Biomolecules. 2020;10(11):1575. doi: 10.3390/biom10111575
9.Zanelati TV, Biojone C, Moreira FA, Guimarães FS, Joca SR. Antidepressant-like effects of cannabidiol in mice: possible involvement of 5-HT1A receptors. Br J Pharmacol. 2010;159(1):122–8. doi: 10.1111/j.1476-5381.2009.00521.x
10.Lake S, Peers C, Daeninck PJ, Bowie C, Milloy MJ, Walsh Z, et al. Clinical and cognitive improvement following treatment with a hemp-derived, full-spectrum, high-cannabidiol product in patients with anxiety: an open-label pilot study. Biomedicines. 2025;13(8):1874. doi: 10.3390/biomedicines13081874
11.Turna J, Patterson B, Van Ameringen M. Is cannabis treatment for anxiety, mood, and related disorders ready for prime time? Depress Anxiety. 2017;34(11):1006–17. doi: 10.1002/da.22664
12.Sarris J, Sinclair J, Karamacoska D, Davidson M, Firth J. Medicinal cannabis for psychiatric disorders: a clinically-focused systematic review. BMC Psychiatry. 2020;20:24. doi: 10.1186/s12888-019-2409-8

Cannabis & Mental Wellbeing