Cannabis and mental health are often mentioned together in the same sentence. In the past, the association was normally a negative one, but research in recent decades is shifting the narrative which has contributed to much of the stigma around the plant.
In its whole-plant form, cannabis is psychoactive – this is because of the delta-9-tetrahydrocannabinol (THC), which is nearly always the most-dominant compound in the herb. And while some find that a recreational cannabis experience can improve their mood and even offer them fresh perspectives on troubling situations, the mind-altering effects can also make mental health problems worse.
For example, somebody who suffers from anxiety could become increasingly fretful and paranoid when under psychoactive influence, as the substance distorts their reality – in the same way that positive emotions tend to become euphoric after using marijuana, negative feelings can also become more pertinent.
However, cannabis is not just THC, and since the uncovering of the endocannabinoid system (ECS) in the 1990s, scientists have found out much more about cannabidiol (CBD), an important compound that does not have psychoactive properties. CBD went under the radar for many years, as the vast majority of cannabis research was centered around the entire plant, or just THC.
But studies on the effects of isolated CBD have yielded intriguing findings, generating hope that the cannabinoid could be used in the treatment of depression, anxiety, psychosis, schizophrenia and more, thanks to its balancing impact on the ECS.
In this post, we’ll concentrate on the existing research for CBD and various mental illnesses, discuss what studies medical researchers could conduct next, and consider which CBD products may benefit patients the most.
Depression is a complex mood disorder that often cannot be solved by medication alone. However, for many, the existing treatments for the condition are substandard. Since the 1980s, doctors have typically prescribed selective serotonin reuptake inhibitors (SSRIs) such as Zoloft, Paxil and Prozac as the first drug of choice. Curiously, despite SSRIs being used for around 30 years, the precise mechanism in which they reduce depressive symptoms is unknown.
While some experience relief, and there is some evidence that these drugs can support neurogenesis, SSRIs come with plenty of drawbacks. Patients generally need at least two weeks of treatment before noticing any benefit, and side effects include drowsiness, nervousness, dizziness, nausea and insomnia. More concerningly, some patients report that SSRIs cause depersonalization.
Cannabis scientists are optimistic about CBD for depression, because of the faster onset of effects and the lack of severe side effects. Researchers at Sao Paulo State University carried out a study published in the Molecular Neurobiology journal in 2018, which detailed how CBD treatment showed “sustained effects against depression.”
The rats were administered a single dose of CBD, which had a beneficial effect for up to seven days before synaptic protein levels, a key signal of depression in humans, began to rise in the prefrontal cortex. This region of the brain is involved with many of the organ’s most complicated processes and contributes significantly to personality development. The researchers noted that levels of brain-derived neurotrophic factor (BDNF), which is vital for neuronal survival and neurogenesis, spiked following the CBD treatment. Synaptogenesis, a process where synapses form between neurons, also occurred in the prefrontal cortex of the treated rats.
The same researchers behind this study have also demonstrated that CBD can facilitate improvements in the hippocampus, another region of the brain implicated in depression.
The next step in determining the efficacy of CBD as a depression medication is for clinical studies on humans. Potentially, CBD could be prescribed to patients who do not respond to SSRIs, and it could also be used in conjunction with existing antidepressants.
CBD may also provide depression relief by boosting the amount of anandamide available in the brain. Anandamide is a neurotransmitter and endocannabinoid with antidepressant properties. The cannabinoid binds with CB1 receptors, which are expressed in large concentrations in the prefrontal cortex and hippocampus.
Theoretically, any CBD product where the cannabinoids are taken orally, either by inhalation or ingestion, could help to alleviate depression. CBD edibles do not take effect as quickly as CBD vape oil and e-liquid, but the therapeutic benefits of the former last for several hours longer. However, the fast delivery of vaporizing could be well-suited for helping patients to break out of a mood slump.
Anxiety is another mental health disorder that has proven challenging to remedy – SSRIs, again, are among the most common prescribed treatments. Scientists are uncertain as to the exact causes of anxiety, but genetics, psychological and environmental factors may all play a part. Chemical imbalance which causes hyperactivity in the brain could also lead to anxiety – as the brain fires off impulses at a higher-than-average rate, the result is overthinking and rapid thinking.
Thankfully, CBD may help to bring the mind back into a state of calm, giving relief to those who suffer from both generalized and social anxiety. Interestingly, one of the earliest pieces of compelling evidence that CBD could be effective at treating anxiety came in 2011, a few years prior to the initial mainstream swathe of interest in the compound. However, this study, from Italy, found that CBD worked better than a placebo for those with social anxiety.
The participants, who had never previously tried treatment for their condition, were split into two groups – one was given a 600mg dose of CBD in a gelatin capsule, while the other was given an identical-looking capsule that contained a placebo. They then took part in a simulated public speaking test, with their reactions assessed at regular intervals. The group pre-treated with CBD experienced significantly less anxiety and reduced cognitive impairment and performed their speech with less discomfort.
The study did not investigate the mechanisms in which CBD decreased anxiety, however more recent studies have identified the serotonin system’s 5-HT1A receptor and GABA neurotransmitters as integral to the process. CBD is an agonist of this serotonin receptor, and a positive allosteric modulator of the GABAA receptor, which GABA neurotransmitters latch onto. GABA is an inhibitory neurotransmitter which can rebalance an overexcited brain – GABA supplements are also thought to improve sleep and elevate mood.
Anxiety is invariably at worst when symptoms emerge from nowhere and become overwhelming in a matter of minutes. This can happen when a situation changes unexpectedly – a person with social anxiety could become uncomfortable when in the presence of people they don’t know. Acute symptoms require fast treatment, which makes CBD e-liquid an ideal solution. For situations where the anxiety can anticipate when their condition is going to strike, pre-treating with edibles like CBD gummy bears can be a wise move – these kick in within the hour and help keep the user relaxed for several hours.
Psychosis and schizophrenia
Cannabis use has been linked to triggering both psychosis and schizophrenia due to the psychoactivity. However, as we know, the psychoactive effects are down to THC, and specifically, the agonising of the CB1 receptor in the ECS. But CBD has the complete opposite effect to THC, in that it is an antagonist of the CB1 receptor, meaning it has intriguing potential as an antipsychotic medicine. The presence of CBD in a cannabis strain has been found to reduce its psychoactive potency, hence why recreational growers seek to grow plants with as high a THC to CBD ratio as they can.
The antipsychotic properties of CBD have actually been studied since before the discovery of the ECS, but the understanding of how this effect is produced has enhanced the compound’s medicinal credentials. Studies on animals have found that CBD’s antipsychotic qualities are much different to those of existing anti-psychotic drugs, and this translates in the absence of serious side effects – CBD appears to influence the temporal cortex and the striatum. Current drugs for psychosis and schizophrenia are notorious for causing restlessness, sleepiness and increasing the risk of diabetes.
Surveys and case reports have shown how people are treating these illnesses with CBD, but until high-quality clinical trials are conducted on humans, this non-psychoactive cannabis medicine cannot be prescribed with confidence.
The potential of cannabis has a treatment for mental health issues – and not an aggravator – is fantastic news for a field of medicine which has struggled to progress in recent times. Hopefully the necessary research will be done in the near future, and that patients who require alternative treatment options will be able to get them.