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CBD Oil and Depression: Is there enough evidence to suggest CBD can help?

CBD Oil and Depression: Is there enough evidence to suggest CBD can help?

 Cannabidiol (CBD) is a phytocannabinoid, a natural compound found in the cannabis plant, also known as hemp or marijuana, depending on the level of tetrahydrocannabinol (THC). THC is the psychoactive compound found in cannabis associated with the “high” effect associated with taking cannabis. CBD as an isolated cannabinoid does not cause psychoactive effects like THC does.

There is some clinical research on CBD including studies related to depression and anxiety, as well as pain and sleeping disorders, but the research is limited. In this article we take a deeper look into what defines depression, as it is a disorder that effects so many people, and whether there is evidence to prove that CBD can help.

What is Depression?

Some people think depression is trivial and not a genuine health condition. They are wrong. Depression is a real illness with real symptoms. It is not a sign of weakness or something you can "snap out of" as some might suggest.

Depression is a common mental disorder that causes people to experience depressed mood, loss of interest or pleasure, feelings of guilt or low self-worth, disturbed sleep or appetite, low energy, and poor concentration. It lasts for a long time and effects your everyday life.

Globally, more than 264 million people suffer with depression. People of all ages. (1)

In its mildest form, depression can mean just being in low spirits. It doesn't stop you leading your normal life but makes everything harder to do and seem less worthwhile. At its most severe, depression can be life-threatening because it can make you feel suicidal. We all have times when we feel low, feeling sad or miserable about life in general. Usually these feelings pass in due course. But if the feelings are interfering with your life and don't go away after a couple of weeks, or if they come back over and over again for a few days at a time, it could be a sign that you're experiencing depression.

What causes Depression?

Whilst there is no single cause of depression, it is still unclear exactly what causes someone to become depressed. It can occur for a variety of reasons and has many different triggers of which vary a lot between different people.

For some, a combination of different factors may cause their depression. For others it could be past traumatic experiences during childhood. There is good evidence to suggest that difficult experiences from a young age can make you more vulnerable to experiencing depression later in life. Some find that they become depressed without any obvious reason.

It can be an upsetting or stressful life event such as, the loss of someone close, breakdown in a relationship, illness or injury, redundancy, unemployment or financial worries.

A poor diet and lack of sleep and exercise can affect your mood and make it harder for you to cope with difficult things going on in your life. Although a poor diet, or not getting enough sleep or exercise, cannot directly cause depression, they can make you more vulnerable to developing it.

You may have a higher risk of depression if you have a longstanding or life-threatening illness, such as cancer. Head injuries are also an often, under-recognised cause of depression. A severe head injury can trigger mood swings and emotional problems.

Some people may have an underactive thyroid resulting from problems with their immune system. In rarer cases, a minor head injury can damage the pituitary gland, which is a pea-sized gland at the base of your brain that produces thyroid-stimulating hormones. This can cause a number of symptoms, such as extreme tiredness and a lack of interest in sex, which can in turn lead to depression.

You may be more vulnerable to depression if you have certain personality traits, such as low self-esteem or being overly self-critical. This may be because of the genes you've inherited from your parents, your early life experiences, or both. If someone in your family has had depression in the past, such as a parent or sister or brother, it's more likely that you'll also develop it.

Coronavirus (Covid-19) is impacting all our lives, and lockdown has brought about it’s own issues that are affecting peoples mental health. One of the feelings millions of us are experiencing during the current coronavirus pandemic is loneliness. In our combined efforts to stay safe and save lives, our usual ways of seeing family, friends or just familiar faces have been put on pause. In a matter of weeks, social distancing left millions more people in the UK feeling isolated. Many of us feel lonely from time to time and these short-term feelings shouldn’t harm our mental health. However, the longer the pandemic goes on for, the more these feelings become long-term. Long-term loneliness is associated with an increased risk of certain mental health problems, including depression, anxiety and increased stress. The impact of long-term loneliness on mental health can be very hard to manage.

Common Treatments for Depression

 There are various treatments that have been found to help with depression. The type of treatment recommended by a GP would be based on the type of depression you have.

For mild depression, a physical activity programme could work. There's evidence that exercise can help depression. You may be referred to a group exercise class specifically designed for people with depression and run by qualified professionals.

A self-help programme. Talking through your feelings can be helpful. You could talk to a friend or relative, or you could ask a GP or local psychological therapies service if there are any self-help groups for people with depression in your area.

A computer-based CBT programme. Your GP might refer to this as computerised cognitive behavioural therapy (CCBT). Some people find CCBT helps them understand their depression and challenge negative thoughts.

If your depression is more severe, you might be offered an antidepressant medication. Psychiatric drugs which are licensed to treat depression and can only be prescribed by healthcare professionals, such as your GP.

There are various different types which work by boosting the activity of chemicals in the brain, particularly serotonin and noradrenaline, which are thought to regulate your mood. By causing a change to your brain chemistry, antidepressants may lift your mood but they do not work for everybody and there is no scientific evidence that depression is caused by a chemical imbalance. Up to 40% of people with depression have hard to treat, or treatment resistant depression, meaning they do not experience a noticeable improvement in their symptoms after trying at least two different antidepressant medications. (2)

Selective serotonin reuptake inhibitors (SSRIs) mainly work by blocking the reuptake of serotonin into the nerve cell that released it. This means that the serotonin acts for longer on your brain and body. SSRIs work just as well as older antidepressants and have fewer side effects, although they can cause nausea, headaches, a dry mouth and problems having sex. But these side effects usually improve over time. SSRIs are the most commonly prescribed type of antidepressant in the UK.

Tricyclic antidepressants (TCAs) have been around for longer than SSRIs. TCAs work by raising the levels of Serotonin and noradrenaline in the brain. They also affect other chemicals in the body and can cause more unpleasant side effects than other antidepressants.

Serotonin-noradrenaline reuptake inhibitors (SNRIs) are the newest antidepressants available and have been around since the 1990s. Like TCAs, they change the levels of serotonin and noradrenaline in the brain, but not routinely prescribed because they can lead to a rise in blood pressure.

The Link Between Serotonin and Depression

Serotonin is a neurotransmitter, a type of chemical that helps to send messages from one area of the brain to another. It is believed that serotonin is linked to brain cells involved in a range of psychological processes, such as mood and behaviour. As well as brain cells that influence some body functions and systems such as sexual desire and functioning.

Serotonin is widely known as being one of the brain’s ‘happy chemicals’, because it appears to be able to influence mood. Research shows that high levels of serotonin in the brain are linked to elevated mood and feeling happy, whereas low levels of serotonin are linked to the symptoms of depression, including feeling sad, upset, and generally low in mood. (3)

The idea that serotonin levels are related to depression is further supported by the fact that people who are experiencing a ‘comedown’ after drinking alcohol or taking drugs, report feeling sad and depressed. This is because alcohol and drugs such as ecstasy/MDMA are known to cause levels of serotonin to peak and then reduce very quickly. This sudden reduction in serotonin levels therefore has a negative impact on a person’s mood during the drug comedown stage.

However, while there is certainly a connection between serotonin and depression, the direction of this relationship is unclear in terms of whether low serotonin causes depression, or whether depression causes low serotonin.

Alternative Treatments for Depression

 Yoga practice can modulate stress response systems by reducing heart rate, lowering blood pressure, and easing respiration, reducing perceived stress and anxiety. One study on the benefits of hatha yoga versus health education found that yoga does alleviate symptoms of depression and the effects were long term. (4) Hatha yoga includes physical poses, controlled breathing, and a short period of deep relaxation or meditation.

Meditation is an active training of the mind. It involves 30-40 minutes per day of acceptance of feelings and thoughts without judgment, relaxation of the mind and body and can help reduce symptoms of anxiety and depression.

There are various herbal extracts, new and old, that are said to help with depression. Natural remedies in general are becoming increasingly popular these days.

St. John’s Wort (Hypericum perforatum) has been used in folk medicine for centuries as it was believed to have medical properties. Oily extracts were produced to treat wounds, including by the Knights Hospitaller, the Order of St John, after battles in the Crusades, which is most likely where the name derived. Although the evidence is limited, there are some studies and research that support the efficacy of St. John’s Wort as a treatment for depression in humans. A 2008 Cochrane review of 29 clinical trials concluded that it was superior to placebo in patients with major depression, as effective as standard antidepressants and had fewer side effects, (5) although in some cases, St. John’s Wort can have some serious side effects. Side effects range from minor inconveniences (upset stomach) to major and life altering (confusion, muscle stiffness, significant drop in body temperature, and psychosis).

Cannabidiol (CBD) has seen a surge in popularity in recent years, as new research explores its potential health benefits. CBD, particularly CBD-rich cannabis oil, as a tool in the fight against depression is now a key area of interest for consumers and researchers alike.

So far CBD does not appear to cause many side effects, but some people may be more sensitive to it than others. Short term side effects include diarrhea, fatigue and changes in weight or appetite. It is hard to know if CBD causes any long-term side effects due to a lack of research. So far, experts have not identified any major long-term risks.

CBD: What the research suggests so far

Some research suggests that CBD oil and other CBD products may be beneficial for symptoms of depression, as shown in both human and animal studies. Although research is limited, a more recent 2018 review conducted by Brazilian researchers concluded that CBD does have anti-stress effects, which may reduce depression related to stress. (6) This is an area that is still being actively studied, with new research and reviews been published more frequently. As researchers begin to better understand CBD and its potential benefits or concerns, information about how to most effectively use the product will continue to be updated.

Studies suggest that CBD shows great psychiatric potential. Studies of animal models using CBD as an anxiolytic-like and antidepressant-like compound suggested that CBD did exhibit an anti-anxiety and antidepressant effect in the animal models tested. The interaction that CBD was found to have on the serotonin 1a receptors could hold promising potential. (7) Activation of this receptor has been involved in the mechanism of action of anxiolytic, antidepressant and antipsychotic medications.

Currently available antidepressants have a substantial time lag to induce therapeutic response and a relatively low efficacy. CBD is a promising compound since it shows large-spectrum therapeutic potential in preclinical models and humans. However, its antidepressant properties have not been completely investigated. A 2018 study aimed to investigate whether CBD could induce rapid, yet sustained, antidepressant-like results in male rodents bred to develop depression-like symptoms.

After a single dose, acute antidepressant effects were observed within 30 minutes. Also occurring was an increase in brain-derived neurotrophic factor (BDNF), which is a protein that plays a critical role in mood disorders. The researchers concluded that CBD offers a promising therapeutic profile as a potential fast-acting antidepressant treatment option. (8)


There are many anecdotal reports of people using CBD successfully to treat depression but clinical trials in humans are lacking and more research is definitely required. CBD products are increasingly being used and studies have shown that CBD offers a promising therapeutic profile as a potential fast-acting antidepressant treatment option. If you are interested in trying any CBD products you should talk with your GP. While studies show the compound is generally safe, it may interact with other medications you are taking. It is a good idea to review medications and other supplements you are taking before you begin using CBD.

(1) https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(18)32279-7/fulltext

(2) https://www.camh.ca/en/camh-news-and-stories/unraveling-and-treating-depression

(3) https://pubmed.ncbi.nlm.nih.gov/8852528/

(4) https://pubmed.ncbi.nlm.nih.gov/28382883/

(5) https://en.wikipedia.org/wiki/Hypericum_perforatum#Traditional_medicine

(6) https://www.frontiersin.org/articles/10.3389/fimmu.2018.02009/full

(7) https://pubmed.ncbi.nlm.nih.gov/24923339/

(8) https://link.springer.com/article/10.1007%2Fs12035-018-1143-4

James CaseEditor