New Research on Depression Has Big Effect on CBD

It has been a common understanding that low levels of serotonin are linked to depression and anxiety. Chemical imbalances of this neurotransmitter have been repeatedly associated with mental health.

This has led to the development of Selective Serotonin Reuptake Inhibitors (SSRIs), an anti-depressant medication that targets the levels of serotonin in the brain. Their goal is to increase serotonin, thus staving off depression.

At the same time, many analyses and clinical trials examining the effectiveness of CBD on depression have noticed an interaction with brain neurotransmitters, particularly serotonin. The assumption has been that CBD, just like SSRIs, improves the levels of serotonin and has a similar effect to these drugs.

A surprising find

Given how prevalent this thinking was, a recent research paper, published in Molecular Psychiatry, came as a shock to many. The study, called “The serotonin theory of depression: a systematic umbrella review of the evidence,” investigated serotonin levels in the brains of people with depression and those not suffering from depression, Surprisingly, it found no noticeable differences. That implies that serotonin may not be responsible for depression.

Since SSRIs are actively targeting serotonin levels in the brain, the study is directly questioning the effectiveness of these drugs. In addition, it raises questions regarding the role that CBD plays in the brain.

According to recent statistics, 17% of Britons take SSRIs to work around their depression. It is, therefore, no wonder that finding a valuable and dependable solution to depression would improve the lives of millions of Britons.

This is hardly a British phenomenon, of course. Worldwide, more than 264 million people suffer from depression. Depression can severely impair their quality of life and livelihood, hence the interest of the medical community in solving the mysteries of depression. 

The recent research on depression and its findings

The Molecular Psychiatry study analysed previous studies and concluded that serotonin levels should not be blamed for depression, as the researchers found no significant reduction in serotonin levels in people suffering from depression.

The review went a step further and questioned the effectiveness of SSRIs that target brain chemical imbalances. The researchers suggested that perhaps other steps, such as therapy and anxiety management, could be more effective than anti-depressant medication.

How effective are SSRIs?

Even so, findings suggest that SSRIs are relatively successful. A 2020 paper suggested that 40 to 60% of people who took SSRIs for six to eight weeks noticed significant changes in their mood and depression levels.

While that leaves an important percentage of people who did not observe a change in their mental condition, findings also showed that SSRIs were more effective in severe cases of depression as opposed to mild ones.

Finally, SSRIs come with significant side effects like dizziness, nausea, headaches, diarrhoea, dry mouth, constipation, and sexual dysfunction. People with depression are often concerned about the side effects of these medications and are interested in findings dependable alternatives.

The recent study seems to question the way SSRIs are believed to work. And yet, SSRIs work in many cases. So, if low serotonin levels are not the actual cause of depression, then how do SSRIs affect the brain to reduce depression?

What causes depression?

Depression cannot be waved away as a simple brain chemical imbalance.

Understanding how the human brain works is difficult. Mental conditions such as anxiety, depression, social anxiety, and PTSD still require a lot of research to understand how the brain is affected and whether brain chemicals and neurotransmitters are responsible for mental illnesses. What we do know is that a number of factors are involved, from nerve cell regeneration to genetic predisposition.

Nerve cell regeneration

A recent study by the Harvard Medical School concluded that chemical imbalances are not responsible for depression and mental disorders. Instead, what seems to make a difference in the world of mental conditions—and depression in particular—is “nerve cell connections, nerve cell growth, and the functioning of nerve circuits.” The more such connections exist in the brain and the higher the nerve cell growth, the less likely it is for the brain to exhibit depression.

Depression appears to be associated with the amygdala, the hippocampus, and the thalamus. Findings are showing that people with depression have smaller-sized amygdala than those that don’t show depression signs. A smaller amygdala will have fewer nerve connections, which could explain the idea behind the role of nerves rather than neurotransmitters in the onset of depression.

In addition, the Harvard Medical School goes a step further. SSRIs appear to work only after 6 to 10 weeks of consistent dosage. If it were just an issue of serotonin levels, a few days of SSRIs should be enough to return these to a healthier level.

What if SSRIs have a neuroplastic effect instead, i.e. they help promote the creation and growth of nerves and nerve connections? Since these take time to occur, that would explain why SSRIs require time to start acting.

Other factors that cause depression

There are other factors unrelated to brain imbalances that cause depression, as these are presented by the NHS:

• Older people tend to suffer more from depression than younger ones.
• Troublesome life events, such as a divorce, a death in the family, or health issues can also trigger depression.
• There appears to be a genetic component: people with a family member who suffers from depression are more prone to experience depression themselves.
• Loneliness and the lack of social connections with friends, relatives, colleagues, and even neighbours have also been associated with depression.
• Finally, drug and alcohol abuse are closely linked to depression.

Where does this leave CBD?

According to research, 38% of Britons take CBD to manage their anxiety or depression, making this the second most common reason cited after pain management.

Why do people experiment with CBD?

Many people who suffer from depression don’t see significant improvements with conventional SSRIs and other anti-depressant medications.

Others are forced to give them up because they experience serious side effects, which have a strong impact on their quality of life and overall well-being.

In addition, some don’t like how SSRIs must be taken for long stretches of time, often for years. They feel they become dependent on a drug.

Finally, some fear relapses once they stop their SSRIs prescription. This is not an unfounded fear, as relapses have been noticed in cases where a person stops taking their anti-depressant medication.

The endocannabinoid system

Research, analyses, and reviews are examining the potential of CBD with regards to depression. The reason behind this hypothesis is the endocannabinoid system (ECS).

The ECS is responsible for keeping many bodily functions in balance. The breadth of these functions is impressive and includes appetite, learning, motor and temperature perception, reproduction, inflammation, pain perception, and mood.

The ECS works with two human cannabinoids. When something that belongs to the responsibility of the ECS is out of sync, these two endocannabinoids travel to their respective receptors, attach to them, and alert the body to start fixing the problem. These receptors are found throughout the body, but are found in particularly high numbers in the immune system and the brain.

CBD appears to have a close affinity to one of these human cannabinoids and seems to ‘converse’ with the ECS. While CBD doesn’t bind to the cannabinoid receptors, it assists the ECS and seems to make it work better and more effectively.

How does CBD affect depression?

Anecdotal evidence suggests that CBD may be helpful with depression. While highly encouraging, however, this evidence needs to be corroborated by research.

A research paper from 2019 showed that CBD appeared to be effective in animals with depression. Interestingly, the effectiveness of CBD was dose-dependent. While researchers saw an improvement, they still need to understand whether CBD affects the levels of serotonin or whether it has a neuroplastic effect.

Another 2019 paper concluded that CBD had fast and sustained anti-depressant effects. It also concluded that CBD was involved in synaptic plasticity and the activation of signalling pathways. Again, these findings point to an interaction with the nerves rather than the levels of serotonin in the brain.

Finally, a more recent 2021 paper concluded that CBD was more effective in cases of moderate or severe depression—a similar finding to SSRIs.

CBD may help with depression in indirect ways

The recent Molecular Psychiatry paper, which questioned the relationship between depression and low serotonin levels, suggests that people with depression should consider other therapeutic paths to their mental condition. Therapy, better stress management, exercise, and deeper and better social connections could be more successful treatments for depression, particularly in the case of people who do not respond to SSRIs.

In most of these areas, CBD could be a helpful partner.

Because of its interaction with the ECS, CBD may help with stress and anxiety. Many people take CBD to help them fend off anxiety and panic attacks. People who experience chronic anxiety may also benefit from CBD, according to research, and CBD appears to be helpful with social anxiety as well.

A calmer outlook on life might support people and ward off depression. Also, because CBD can relax and calm people down, it may be beneficial for sleep disorders. A calmer mind is easier to achieve quality sleep, which is associated with better mood, feeling rested, and more productive days. All these are particularly helpful against depression.

CBD for depression: we still have a lot to discover

Just when we thought that we knew how the brain works, new findings come to question our beliefs. While serotonin could be involved in mental disorders like depression, it is increasingly emerging that other variables are at play.

This is a good opportunity for the research community to look at its findings from a different perspective. Instead of focusing on serotonin, they could include CBD in their clinical trials and see how CBD interacts in the brain and whether it manages to affect depression.

A temporary setback in mental research could thus be a great stepping stone for more consistent research into CBD and its potential mental health benefits.