Specialisation: Negative Effects Of Medical Marijuana

Negative Effects of Medical Marijuana on Mental Health


In Australia, medical marijuana can be used with a prescription from a medical practitioner. The use is regulated by the Therapeutic Goods Administration (TGA), which oversees the safety and quality of medicines in Australia. Despite the legal availability of medical marijuana in Australia, its use can result in negative health effects, like the potential for worsened depression and increased anxiety caused by interference with the working of the brain system. This paper concludes that these health risks associated with medical marijuana can be addressed by quitting or using marijuana in moderation, seeking social or professional help, and practicing self-care.

1. Introduction

Medical marijuana is a controversial topic that has gained popularity in recent years. In Australia, the use of medical marijuana is legal, but there are strict regulations regarding its use. While there is some evidence indicating that prescribed marijuana can be beneficial for certain health conditions, its use is also associated with possible adverse effects, especially on mental health. Medical marijuana contains cannabidiol (CBD) and tetrahydrocannabinol (THC), which have psychoactive effects on the brain. While mental health disorders are a significant public health issue in Australia, the use of medical marijuana is linked to some mental health issues like depression and anxiety. Therefore, this report provides an overview of the current literature on the effects of prescribed marijuana on mental health, particularly depression and anxiety among Australians.

2. Findings

2.1: Depression and Anxiety

According to available research, medical marijuana can have negative impacts on mental health, especially when used inappropriately and excessively. However, studies conducted in Australia are mixed, with some suggesting medical marijuana alleviates symptoms of depression and anxiety, whereas other evidence supports the hypothesis that medical marijuana increases these symptoms. Medical marijuana disrupts the balance of neurotransmitters in the brain, especially serotonin and dopamine, which plays a huge role in regulating mood. The disruption of the serotonin system leads to increased symptoms of depression and anxiety as the decreasing serotonin receptor sensitivity reduces the effectiveness of this system in regulating mood and anxiety (Baltz & Le, 2020). Excessive use of medical marijuana leads to increased levels of THC, which is associated with depression and anxiety symptoms. A high level of THC overstimulates the amygdala, the part of the brain which is involved in processing emotions like anxiety and fear. Such high levels of THC lead to increased panic and anxiety. Furthermore, high levels of THC alter the prefrontal cortex, a brain system that is involved in impulse control, planning, and decision-making (Baltz & Le, 2020). Thus, altering the prefrontal cortex results in increased risky behaviors and decreased impulse control, contributing to depression.

2.2. Solutions

Studies have suggested that cognitive-behavioral therapy may (CBT) be an effective solution to depression and anxiety caused by the use of medical cannabis. CBT focuses on determining and changing negative behaviors and thought patterns that result in depression and anxiety (Buckner et al., 2021). Motivational enhancement therapy (MET) focuses on assisting individuals to overcome resistance to change or ambivalence. MET is effective in reducing the use or reliance on marijuana and addresses symptoms related to depression and anxiety (Buckner et al., 2021). Moreover, chronic users of medical marijuana are advised to seek social or professional support from family, friends, or mental health professionals since they can provide practical advice and emotional support to help manage depressive and anxiety symptoms and also develop coping strategies.

3. Discussion

According to Gold (2020), the use of cannabis carries unique risks and worsens depression symptoms when used as an ersatz antidepressant. When marijuana is prescribed for medical reasons or as a relaxation tool, there are associated short and long-term changes in mental health like depression and mood. A longitudinal cohort study conducted on the use of cannabis established that early use of marijuana is risky and is linked to anxiety and depression in adult life (Gold, 2020). A study published in the Journal of Affective Disorders indicated that people who used medical marijuana for managing chronic pain demonstrated high levels of depression and anxiety than other who did not use medical marijuana. According to Bahorik et al. (2018), the psychoactive effects of THC contribute to depressive symptoms by altering neurotransmitter function and brain chemistry. A study conducted on 150 patients who used medical marijuana in Australia for various reasons like epilepsy and chronic pain found that those patients had increased symptoms of depression, as their questionnaire responses revealed (Langlois et al., 2021). Therefore, the frequent use of medical marijuana increases the risk of developing anxiety and depression due to the impact of THC on the endocannabinoid system, which is essential for regulating stress and mood responses. For medical cannabis users who suffer depressive and anxiety symptoms, researchers suggest reducing or quitting the use of medical cannabis to allow the body to eliminate such symptoms.

4. Conclusion

Medical marijuana is used for different reasons, such as relieving physical or mental health symptoms through self-medication. Various studies have indicated that Australians use prescribed cannabis for managing chronic pain, sleep disorders, PTSD, migraine, seizure management, and neuropathic pain. However, continued use of marijuana leads to an increase in some health problems or creates new ones, such as depression and anxiety. It may worsen depression symptoms for early or heavy users, and due to its addictiveness, people may find it challenging to seek professional help, which further makes it challenging to recover from depression. Different studies have supported the negative effects caused by medical marijuana on users’ mental health, with many patients reporting increased depression and anxiety symptoms. This is due to the interference of brain processes that control mood and anxiety and increased THC levels that result in challenges in controlling emotions. As a result, using medical marijuana requires individuals to monitor their mental health and seek professional help when depression and anxiety symptoms exacerbate.

5. Recommendations

  • Users should seek alternative treatments available for their physical or health conditions, such as exercising, meditation, mindfulness, and cognitive-behavioral therapy, before considering medical marijuana, which can worsen depression and anxiety.
  • The negative effects of marijuana on mental health are normally influenced by the dose and frequency of use. Users are advised to use medical marijuana moderately since excessive or inappropriate use can trigger symptoms of anxiety and depression.
  • Users should seek help from mental health professionals to determine a treatment plan that better meets their needs. Marijuana is addictive, and failure to seek help can make it harder to recover from depressive symptoms.
  • The effective way to avoid depression and anxiety triggered by medical marijuana is to stop using it, as it helps reduce the symptoms and allows the body to recover. Besides, it is recommended to practice self-care by engaging in activities that enhance physical and mental wellness, like a healthy diet and exercise. Such activities improve mood and reduce stress and anxiety.


Bahorik, A. L., Sterling, S. A., Campbell, C. I., Weisner, C., Ramo, D., & Satre, D. D. (2018). Medical and non-medical marijuana use in depression: Longitudinal associations with suicidal ideation, everyday functioning, and psychiatry service utilization. Journal of affective disorders, 241, 8–14. https://doi.org/10.1016/j.jad.2018.05.065

Baltz, J. W., & Le, L. T. (2020). Serotonin Syndrome versus Cannabis Toxicity in the Emergency Department. Clinical practice and cases in emergency medicine, 4(2), 171–173. https://doi.org/10.5811/cpcem.2020.1.45410

Buckner, J. D., Morris, P. E., & Zvolensky, M. J. (2021). Integrated cognitive-behavioral therapy for comorbid cannabis use and anxiety disorders: The impact of severity of cannabis use. Experimental and clinical psychopharmacology, 29(3), 272–278. https://doi.org/10.1037/pha0000456

Gold M. (2020). Medicinal Marijuana, Stress, Anxiety, and Depression: Primum non nocere. Missouri medicine, 117(5), 406–411.

Langlois, C., Potvin, S., Khullar, A., & Tourjman, S. V. (2021). Down and High: Reflections Regarding Depression and Cannabis. Frontiers in psychiatry, 12, 625158. https://doi.org/10.3389/fpsyt.2021.625158