CBD and schizophrenia: Common side effects seen throughout the study
We can all agree that mental illness can be crippling and a source of stigma for those individuals suffering from it. Specifically, psychosis is a type of mental illness that can manifest with severe symptoms such as paranoia or hallucination. Although they can be controlled, conditions rooted in psychosis, such as schizophrenia, can pose a great challenge and severely reduce quality of life.
The toxicity profile for drugs used to treat schizophrenia is often questioned by physicians. Additionally, common antipsychotic drugs in the market do not inspire much trust in individuals taking them, which can many times lead to treatment non-compliance. For this reason, healthcare providers are looking for new antipsychotic agents that reduce unwanted side effects while giving individuals the opportunity to live long, healthy and fulfilling lives.
Of course, cannabinoids have also been a topic of debate when it comes to treating schizophrenia and other psychosis-related illnesses. However, some cannabinoids such as THC have unwanted psychoactive effects and can even exacerbate common psychosis symptoms such as hallucinations.
What if I were to tell you there is a cannabinoid that does not possess these unwanted side effects like THC does, but still possesses strong therapeutic properties against schizophrenia?…
Cannabidiol (CBD) is a cannabinoid that shows particular promise in the healthcare field, specifically in the area of psychosis-related illnesses. Healthcare providers seem to be attracted to it because it maintains those therapeutic properties and has low affinity for CB1 receptors. CB1 receptors are endocannabinoid receptors responsible for interacting with exogenous psychoactive cannabinoids like THC.
The following article will give a very brief review on some of the current research regarding the use of CBD for the purposes of managing schizophrenia. With the rise in cases of mental illness, CBD and schizophrenia have been of recent interest to medical scientists seeking safer ways to ameliorate this condition.
A multicenter randomized controlled study assessed the use of CBD as a therapy for schizophrenia
For patients suffering from schizophrenia, the first line of defense against the condition tends to be antipsychotics. Antipsychotics exert their effect by acting as antagonists and interacting with central dopamine D2 receptors. Although it is effective in most patients, up to one third of patients react poorly to antipsychotics.
In addition, antipsychotics usually help with positive schizophrenia symptoms that are often mediated by these central dopamine receptors. Negative symptoms and cognitive dysfunction are rarely affected by antipsychotics.
To quickly clarifly, positive symptoms include things like hallucinations, delusions, and paranoia. On the other hand, negative symptoms are things like depression or apathy. The terms negative and positive do not have to do with whether the symptoms are good or bad for the patient. Instead, they have to do with whether the patient is in an excited or lethargic state.
Because they reduce positive symptoms, antipsychotics are still important agents for the management of schizophrenia. However, compounds that do not necessarily act on dopamine receptors, such as CBD, can be used in complement with antipsychotics to treat the other symptoms.
In various studies, CBD has been linked to a reduction in psychotic symptoms in patients suffering from parkinson’s disease. For CBD and schizophrenia, few studies have been done on its efficacy and safety when compared to other medications. One study compared the effects of CBD versus amisulpride in patients with schizophrenia. This study showed that there was a reduction of positive and negative symptoms with both drugs (no significant difference). However, CBD was linked to much fewer adverse side effects when compared to amisulpride.
But that is not all…
A phase 2 multicenter clinical trial was performed at 15 different sites in the UK, Romania, and Poland to test the safety and efficacy of CBD as an adjunctive treatment for schizophrenia. The study was a double blind parallel group trial where patients with schizophrenia were either given 1000 mg/day of CBD or a placebo.
Both treatments were accompanied with the original medication. That is, the antipsychotics were not discontinued. The study enrolled a total of 88 subjects (43 were treated with CBD 45 were given a placebo). According to the author, participants were assessed for positive symptoms, negative symptoms, cognition, improvement and severity of overall symptoms.
Severity of symptoms was shown to decrease in the CBD group compared to the placebo group
Per the results of the assessments, it was seen that positive psychotic symptoms in patients with schizophrenia were significantly reduced in the CBD group compared to the placebo group. However, negative symptoms or pathology of the disease showed no significant difference between the group.
Proportion of patients who respond to CBD treatment was significantly higher than the placebo group.
As previously mentioned, a common problem of antipsychotic medications is that a significant portion of patients do not properly respond to them. The researchers assessed the proportion of those patients (proportion of treatment responders) and found that this proportion was higher in the CBD group. Despite this finding, the amount of patients responding properly in both groups was still small. Therefore, establishing statistical significance was difficult.
According to the study, 78.6% of patients in the CBD treated group were described as improved by their physicians, compared to only 54.6% in the placebo group.
Of course, there is more to this…
Patients in the categories of moderately, markedly, and severely ill decreased from 83.4% to 54.8% in the CBD group. In the placebo group, the proportion of patients in these categories went from 79.6% to 63.6%. In turn, this constituted an increase from 16.7% to 45.2% in the proportion of patients in the mild, borderline or no illness categories for the CBD treated group. On the other hand, the placebo group saw an increase of only 20.5% to 36.4 % in this assessment.
Cognitive function significantly changed in some aspects but remained similar in others when comparing CBD treated group to placebo group
Cognitive functions in both groups was not seen to vary much from the CBD treated to the placebo treated group. One area that showed statistically significant improvement was motor speed. Although this may seem like an added benefit, motor skills may be less important when assessing how a person performs cognitively.
Common side effects seen throughout the study
The table below was provided within the published study and highlights some of the most common side effects seen after CBD or placebo treatment:
The right side of the table shows side effects that were attributable to the treatment and not to anything else the patient might have been exposed to during the study. As it can be seen, CBD reduced some side effects while increasing others. Particularly, an increase in gastrointestinal disorders was seen in the CBD.
Because of CBD’s proposed ability to manage symptoms of irritable bowel syndrome, this result seems somewhat counterintuitive. Nonetheless, this may be the result of drug interactions with the original treatment (although at this point, that statement is simply speculation). For this reason, the study above shows great promise but the safety of CBD in its use against schizophrenia must be continually studied. Additionally, studies with a larger sample of subjects must be performed to be able to establish statistical significance.