Medical Cannabis & Depression: What We Know

Alternaleaf Team
Written by
Alternaleaf Team
Dec 4, 2023
Last updated:
May 2, 2024

Approximately 1 in 7 Australians will experience depression in their lifetime and 1 in 13 Australians have reported experiencing a depressive episode over the last 12 months. The prevalence and impact depression can have makes it clear that we need more education, resources and support for people with the disorder.

Depression is a complex and sometimes misunderstood condition, so it’s important to understand exactly what it is, what the risk factors are and what symptoms it can involve.

What Is Depression?

Depression is a serious illness and can have profoundly negative effects on a person’s quality of life. While sadness and occasional bouts of low energy are normal, people with depression experience these feelings more intensely and for a prolonged period.

A depression diagnosis typically involves the following symptoms being present for at least two weeks:

  • persistent sadness
  • low motivation/energy
  • hopelessness
  • anger
  • a loss of pleasure in activities or things the person once enjoyed.

Depression can also involve physical symptoms including sleep issues, appetite changes, feeling tired or run down, nausea, muscle pain and headaches.

Along with these physical symptoms, people with depression may become socially withdrawn, stop engaging in hobbies and become less productive. They might also turn to alcohol or other substances to try and cope with their symptoms.

Certain factors can increase someone’s risk for depression. For example, depression sometimes runs in families – if your parents or grandparents have experienced depression, you may have a higher chance of developing it as well.

Someone's personality may also predispose them to depression: if you experience low self-esteem or have a low stress tolerance you may be at a higher risk. Finally, abuse, neglect, poverty or exposure to violence can contribute to someone developing depression.

If left untreated, the condition can result in suicidal thoughts or intentions, meaning early detection and support for people with, or at risk for, depression is vital.

Symptoms of Depression

The primary symptom of depression is feeling deeply sad and uninterested in daily activities constantly for a period of 14 days or more. Things that used to make you feel satisfied or happy no longer hold the same appeal, rendering you withdrawn from the world.

Along with this can come a variety of other symptoms, such as anxiety, anger, excessive crying, feelings of worthlessness, trouble concentrating, changes in sleep patterns, weight gain or loss due to appetite changes, decreased libido, slowed movements, and thoughts of suicide.

Depression can affect women and men differently. For example, men are more likely than women to withdraw from their family, use substances, experience and express anger, and display risky behaviours when they’re depressed.

In some cases depression can also lead to physical issues such as chronic pain (including headaches and cramps), as well as gastrointestinal (GI) issues.

Does Medical Cannabis Have Any Benefits For Depression?

There’s currently a lack of high-quality studies on how medical cannabis might benefit depression. Although there have been some promising results.

The studies already done have typically relied on self-reported outcomes from patients or lacked a control group. This means that the data on medical cannabis and depression isn’t yet definitive, but some studies show that the potential benefits are worth further investigation.

For instance, one study showed that cannabidiol (CBD), a non-intoxicating cannabinoid, may have some effect on serotonin levels in the brain. Serotonin is a neurotransmitter that is involved in emotion regulation, mood and stress, and is a target of several traditional antidepressants. Researchers have primarily explored CBD’s potential antidepressant effect using animal studies, so more human research is needed before we can say that CBD might help manage depression.

Another recent open-label study found some promise in using CBD to help manage anxiety in young people. The researchers found that along with potentially reducing the participants’ anxiety, CBD may have had a positive effect on their associated depression as well.

The lack of a control group was a limiting factor in the study, along with the small sample size of only 31 participants.

These studies provide good starting points, but more research, ideally randomised controlled trials, are needed to further explore the possible benefits medical cannabis may have for depression.

Could Medical Cannabis Cause or Worsen Depression?

When used under the guidance of a medical professional, medical cannabis is unlikely to cause or worsen depression. However, using illicit cannabis, high-THC strains, using cannabis frequently and/or heavily may increase your risk of developing mental health issues.

One review noted that high-THC cannabis may be associated with a higher risk of depression, but also that people with depression often self-medicate with cannabis products. Because of this, it’s sometimes difficult to determine whether cannabis use causes depression or vice-versa.

The review concluded that low doses of cannabis can generally have positive effects for your mental health, whereas high doses can pose risks and potentially cause or worsen mental health conditions such as depression.

There’s also some evidence to suggest that cannabis may negatively impact a developing brain. One review found an increased risk of developing depression among those who consumed cannabis as adolescents. Medical cannabis clinics don’t prescribe to people under the age of 18 for this reason.

Seeking Treatment for Mental Health Issues

There isn’t enough research to recommend medical cannabis as a treatment for depression, but there have been some promising results with CBD-dominant medications. Medical cannabis is still a new treatment option in Australia — hopefully we’ll see more research into CBD’s potential antidepressant properties in the future.

If you’re worried about how medical cannabis might affect your mental health, it’s important to follow your doctor’s instructions and let them know if your medication is worsening your symptoms. Like other medications, cannabis can pose risks for your mental health when overused or purchased illicitly.

If you’re worried about your mental health, the first thing you should do is book an appointment with your healthcare provider. There are a variety of treatments available for depression, but treatment is highly individual and often requires ongoing monitoring and adjustments until you find what works best for you.

Other resources you may find helpful:


Lifeline Australia - 13 11 14
Suicide Call Back Service - 1300 659 467
Beyond Blue - Anxiety, depression & suicide prevention support
Black Dog Institute - Online help

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