Psych Central Article Here
By John M. Grohol, Psy.D.
You can extract more than 70 different components from a marijuana plant, technically known as cannabis sativa. Two of the most common constituents are delta-9-tetrahydrocannabinol (known colloquially as THC) and cannabidiol (CBD).
Because CBD is not as regulated as THC (though it may be technically illegal under federal laws), nor does it provide any accompanying “high” as THC does, it has become increasingly marketed as a cure-all for virtually any ailment. You can now find CBD oil products online to treat everything from back pain and sleep problems, to anxiety and mental health concerns.
How effective is CBD oil in the treatment of mental disorder symptoms?
Unlike it’s sister THC, CBD doesn’t have any of the associated negative side effects of tolerance or withdrawal (Loflin et al., 2017). CBD is derived from the cannabis plant, and shouldn’t be confused with synthetic cannabinoid receptor agonists like K2 or spice.
Because of its relatively benign nature and more lax legal status, CBD has been more widely studied by researchers in both animals and humans. As researchers Campos et al. (2016) noted, “The investigation of the possible positive impact of CBD in neuropsychiatric disorders began in the 1970s. After a slow progress, this subject has been showing an exponential growth in the last decade.”
Research has shown that CBD oil may be effective as a treatment for a variety of conditions and health concerns. Scientific studies demonstrate the effectiveness of CBD to help relieve some of the symptoms associated with: glaucoma, epilepsy, pain, inflammation, multiple sclerosis (MS), Parkinson’s disease, Huntington’s disease, and Alzheimer’s. It appears to help some people with gut diseases, such as gastric ulcers, Crohn’s disease, and irritable bowel syndrome as well (Maurya & Velmurugan, 2018).
You can find low-end and high-end CBD oil products. The most popular CBD oil product on Amazon.com retails for around $25 and contains only 250 mg of CBD extract.
In a pilot randomized placebo-controlled study of adults with attention deficit hyperactivity disorder (ADHD), a positive effect was only found on the measurements of hyperactivity and impulsivity, but not on the measurement of attention and cognitive performance (Poleg et al., 2019). The treatment used was a 1:1 ratio of THC:CBD, one of the common CBD treatments being studied along with CBD oil on its own. This finding suggests more research is needed before using CBD oil for help with ADHD symptoms.
There are a number of studies that have found that CBD reduces self-reported anxiety and sympathetic arousal in non-clinical populations (those without a mental disorder). Research also suggests it may reduce anxiety that was artificially induced in an experiment with patients with social phobia, according to Loflin et al. (2017).
A review of the literature published in 2017 (Loflin et al.) could find no study that examined CBD as a treatment for depression specifically. A mouse study the researchers examined found that mice treated with CBD acted in a way similar to the way they acted after receiving an antidepressant medication. Therefore, there is virtually little to no research support for the use of CBD oil as a treatment for depression.
Loflin et al. (2017) only found a single CBD study conducted on sleep quality:
Specifically, 40, 80, and 160 mg CBD capsules were administered to 15 individuals with insomnia. Results suggested that 160 mg CBD was associated with an overall improvement in self-reported sleep quality.
There are two human trials currently underway that are examining the impact of both THC and CBD on post-traumatic stress disorder (PTSD) symptoms. One is entitled Study of Four Different Potencies of Smoked Marijuana in 76 Veterans With PTSD and the second is entitled Evaluating Safety and Efficacy of Cannabis in Participants With Chronic Posttraumatic Stress Disorder. The first study is expected to be completed this month, while the second should be completed by year’s end. It can take up to a year (or more) after a study has been completed before its results are published in a journal.
Bipolar Disorder & Mania
The depressive episode of bipolar disorder has already been covered in the depression section (above). What about CBD oil’s impact on bipolar disorder’s manic or hypomanic episodes?
Sadly, this has not yet been studied. What has been studied is cannabis use on the effect of bipolar disorder symptoms. More than 70 percent of people with bipolar disorder have reported trying cannabis, and around 30 percent use it regularly. However, such regular use is associated with earlier onset of bipolar disorder, poorer outcomes, and fluctuations in a person’s cycling patterns and severity of manic or hypomanic episodes (Bally et al., 2014).
More research is needed to see whether supplementing CBD oil might help alleviate some of the negative impact of cannabis use. And additional research is needed to examine whether CBD oil on its own might provide some benefits to people with bipolar disorder.
Compared to the general population, individuals with schizophrenia are twice as likely to use cannabis. This tends to result in a worsening in psychotic symptoms in most people. It can also increase relapse and result in poorer treatment outcomes (Osborne et al., 2017). CBD has been shown to help alleviate the worse symptoms produced by THC in some research.
In a review of CBD research to date on its impact on schizophrenia, Osborne and associates (2017) found:
In conclusion, the studies presented in the current review demonstrate that CBD has the potential to limit delta-9-THC-induced cognitive impairment and improve cognitive function in various pathological conditions.
Human studies suggest that CBD may have a protective role in delta-9-THC-induced cognitive impairments; however, there is limited human evidence for CBD treatment effects in pathological states (e.g. schizophrenia).
In short, they found that CBD may help alleviate the negative impact of a person with schizophrenia from taking cannabis, both in the psychotic and cognitive symptoms associated with schizophrenia. They did not find, however, any positive use of CBD alone in the treatment of schizophrenia symptoms.
Improved Thinking and Memory
There is little to no scientific evidence that CBD oil has any beneficial impact on cognitive function or memory in healthy people:
“Importantly, studies generally show no impact of CBD on cognitive function in a ‘healthy’ model, that is, outside drug-induced or pathological states (Osborne et al., 2017).”
If you’re taking CBD oil to help you study or for some other cognitive reason, chances are you’re experiencing a placebo effect.
As you can see, CBD research is still in its early stages for many mental health concerns. There is limited support for the use of CBD oil for some mental disorders. Some disorders, including autism and anorexia, have had little research done to see whether CBD might help with the associated symptoms.
One of the interesting findings from research to date is that the dosing found to have some possible beneficial effects in research tends to be much higher than what is found in products typically sold to consumers today. For instance, most over-the-counter CBD oils and supplements are in bottles that contain a total of 250 to 1000 mg.
But the science suggests that an effective daily treatment dose might be anywhere from 30 to 160 mg, depending on the symptoms a person is seeking to alleviate.
This suggests that the way most people are using CBD oil today is not likely to be clinically effective. Instead, at doses of just 2 to 10 mg per day, people are likely mostly benefiting from a placebo effect of these oils and supplements.
Before starting or trying any type of supplement — including CBD oil or other CBD products — please first consult your prescribing physician or psychiatrist. CBD may interact with psychiatric medications in a way that is unintended and could cause negative side effects or health problems.
We also do not really understand the long-term effects and impact of CBD oil use on a daily basis over the course of years, as such longitudinal research simply hasn’t yet been done. There have been some reported negative side effects experienced in the use of cannabis, but it’s hard to generalize such research findings to CBD alone.
In short, CBD shows promise in helping to alleviate some symptoms of some mental disorders. Much of the human-based research is still in its infancy, however, but early signs are promising.
For further information
Reason Magazine: Is CBD a Miracle Cure or a Marketing Scam? (Both.)
Thanks to Elsevier’s ScienceDirect service in providing access to the primary research necessary to write this article.
Bally, N., Zullino, D, Aubry, JM. (2014). Cannabis use and first manic episode. Journal of Affective Disorders, 165, 103-108.
Campos, AC., Fogaça, M.V., Sonego, A.B., & Guimarães, F.S. (2016). Cannabidiol, neuroprotection and neuropsychiatric disorders. Pharmacological Research, 112, 119-127.
Loflin, MJE, Babson, K.A., & Bonn-Miller, M.O. (2017). Cannabinoids as therapeutic for PTSD
Current Opinion in Psychology, 14, 78-83.
Maurya, N. & Velmurugan, B.K. (2018). Therapeutic applications of cannabinoids. Chemico-Biological Interactions, 293, 77-88.
Osborne, A.L., Solowij, N., & Weston-Green, K. (2017). A systematic review of the effect of cannabidiol on cognitive function: Relevance to schizophrenia. Neuroscience & Biobehavioral Reviews, 72, 310-324.
Poleg, S., Golubchik, P., Offen, D., & Weizman, A. (2019). Cannabidiol as a suggested candidate for treatment of autism spectrum disorder. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 89, 90-96.