Introduction

Bipolar disorder (BD) is a mental illness that affects many people worldwide. BD has previously been referred to as manic depressive disorder and may appear in other literature under this name. Often, people who have bipolar disorder have severe mood swings. These rapid changes occur quickly and can last from a few weeks up to a few months at a time. These changes in emotion can be overwhelming to many who have the illness and can make life harder to manage.

The severity of these feelings can vary hugely. Some may have episodes of depression or become manic, becoming overwhelmingly happy and overactive. These emotions can vary between episodes. These types of emotions can also become mixed, where one may feel a mix of both mania and depression, making a person restless. This article will explore the potential uses of cannabis to treat bipolar disorder, looking at both the potential benefits and disadvantages.¹

Current treatments for bipolar disorder

Currently, there are medications available to help manage bipolar disorder. These medications are known as mood stabilisers, and sometimes multiple medications are needed for effective treatment of the disorder. Lithium for example, is a notorious mood stabiliser, known for its use for decades now. 

It is often advantageous because of its use in long-term treatment of bipolar disorder to treat all types of episodes, whether manic or depressive. Though its effectiveness has been clear, side effects can make the treatment more challenging to stay consistent with, particularly in those first weeks of treatment.² 

Alternatively, the use of cannabis as a therapeutic for bipolar disorder has been introduced and discussed in medical literature, exploring its potential as a therapeutic for bipolar disorder. Its prospective use as a treatment has presented a possible option for management of the disorder, especially in those who are not so tolerant of traditional medications. This article will explore the potential uses of cannabis to treat bipolar disorder, looking at both the potential benefits and disadvantages.¹

Cannabis and its active compounds

In cannabis, at least 100 cannabinoids can be found. Different cannabinoids have different functions, therefore, their effects on a person will vary between them. Their interaction with the brain can alter things like mood, pain and memory. Tetrahydrocannabinol (THC) and Cannabidiol (CBD) are two examples of the primary compounds that can affect the brain. THC and CBD usually have opposing effects.

• THC: This is the psychoactive cannabinoid responsible for the ‘high’ associated with cannabis use, and it can impair short-term memory
• CBD: This is a non-psychoactive compound recognised for its therapeutic properties, including anti-inflammatory effects and potential benefits for anxiety and pain, and it typically does not impair memory

Cannabinoid receptors are primarily located in the brain and immune cells. Compounds like THC interact with these receptors, influencing various physiological and psychological responses.³

Potential therapeutic benefits of cannabis use in bipolar disorder

Already, many people who have bipolar disorder are frequent users of cannabis. In fact, people with bipolar disorder have often been described to be among the highest users of cannabis. 71% of people diagnosed with BD have had a lifetime of cannabis use.⁴ Several studies have examined the impact of cannabis on psychiatric symptoms. However, much of this research has focused on conditions such as schizophrenia, and literature specifically addressing BD remains limited.⁷

Short-term use of cannabis has been reported by some individuals with BD to provide symptom relief, potentially reducing the severity or frequency of episodes.^4,5 One notable benefit includes improved sleep, which is often disrupted in BD. Cannabis has been shown to aid with insomnia and hypersomnia, and improved sleep may help stabilise mood fluctuations.^9,10 Improved sleep can be advantageous in restabilising mania and other emotions that come with episodes of bipolar disorder.

It's important to acknowledge here that though these studies show benefits in regard to tackling bipolar disorder symptoms, limitations have been highlighted. Research into the effects of cannabis on bipolar disorder is often not extensive enough to determine the effectiveness of cannabis. This should be considered when reading about the potential of cannabis to aid in the management of bipolar disorder.¹⁰ There have also been studies which contradict the advantages of cannabis use in people with BD. Particularly for those who use it as a long-term therapeutic.

Challenges and risks of cannabis use in bipolar disorder

Despite some potential benefits, there are significant risks associated with cannabis use in individuals with BD, particularly with long-term use. Long-term cannabis use can often make both manic and depressive episodes much worse.⁶ Cannabis use disorder is often seen and described in cannabis users who have bipolar disorder. This ultimately means that a person who frequently uses cannabis will become dependent and addicted to the drug.

Although some individuals may initially use cannabis to alleviate BD symptoms, chronic use has been linked to worsening of the disorder. Furthermore, cognitive impairments such as reduced attention, memory problems, and difficulties with verbal fluency are already common in people with BD. The use of THC-containing cannabis may further impair cognitive function.^4,6 

Some studies have indicated that CBD alone may not provide sufficient mood-stabilising effects or alleviate manic symptoms, highlighting the need for more targeted research on cannabinoid-based therapies.⁸

The current research

The literature on whether cannabis can be effective as a treatment is still somewhat limited. Therefore, its use as an effective and safe therapeutic can be unpredictable. There have been some studies which suggest that cannabis can be helpful in other mental illnesses, such as schizophrenia.⁶ However, this has not generally been the case for people with BD and their chronic use of cannabis.

Though studies have been carried out to try and make conclusive decisions on the effects of cannabis in people with BD, there is still much research left to do. The gaps in our knowledge about the relationship between cannabis and BD are still quite significant, and there is no assurance that the effects of cannabis can be accurately predicted.

There is still much research needed to be done, and though the studies we have now are helpful, there is still much uncertainty on the topic. Therefore, the research and literature do not provide enough confidence to conclusively recommend cannabis as a safe therapeutic intervention in psychiatric disorders like bipolar disorder.⁷ Future research will help in ensuring that the therapeutic potential of cannabis is thoroughly explored to ensure safe use of the drug in people with bipolar disorder.

Legal and ethical considerations when using cannabis for bipolar disorder

The legalisation of cannabis and attitudes towards the drug have shifted, especially when used in a medical context. Specifically in the case of using cannabis for psychiatric and pain relief issues. However, it is important to understand whether cannabis is right for a treatment plan. This means not only considering the medical benefits but also legality in your country or region.

Though there has been an increase in availability and use in certain countries, like the United States, for example, this does not necessarily mean that cannabis will be readily accessible as a legal therapeutic. Usually, in the context of medical use, cannabis requires a medical prescription from a medical professional like a general practitioner. Outsourcing cannabis, even if used to treat bipolar disorder, may very well be illegal, regardless of its use for a medical or recreational purpose.

Summary  

The potential use of cannabis as a treatment for bipolar disorder is an area of growing interest but remains under-researched. While short-term use may offer some symptom relief, long-term use has been linked to worsening episodes and cognitive decline. Given the mixed evidence and current limitations of the literature, it is crucial to approach cannabis use in BD with caution. Medical consultation is essential before considering cannabis as a therapeutic option. Future research will play a key role in understanding whether cannabis can be safely and effectively integrated into treatment plans for bipolar disorder.