I wanted to stop by and share this study on the efficacy and safety of CBD as a treatment for schizophrenia. https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.2017.17030325 "Objective: Research in both animals and humans indicates that cannabidiol (CBD) has antipsychotic properties. The authors assessed the safety and effectiveness of CBD in patients with schizophrenia. Method: In an exploratory double-blind parallel-group trial, patients with schizophrenia were randomized in a 1:1 ratio to receive CBD (1000 mg/day; N=43) or placebo (N=45) alongside their existing antipsychotic medication. Participants were assessed before and after treatment using the Positive and Negative Syndrome Scale (PANSS), the Brief Assessment of Cognition in Schizophrenia (BACS), the Global Assessment of Functioning scale (GAF), and the improvement and severity scales of the Clinical Global Impressions Scale (CGI-I and CGI-S). Results: After 6 weeks of treatment, compared with the placebo group, the CBD group had lower levels of positive psychotic symptoms (PANSS: treatment difference=−1.4, 95% CI=−2.5, −0.2) and were more likely to have been rated as improved (CGI-I: treatment difference=−0.5, 95% CI=−0.8, −0.1) and as not severely unwell (CGI-S: treatment difference=−0.3, 95% CI=−0.5, 0.0) by the treating clinician. Patients who received CBD also showed greater improvements that fell short of statistical significance in cognitive performance (BACS: treatment difference=1.31, 95% CI=−0.10, 2.72) and in overall functioning (GAF: treatment difference=3.0, 95% CI=−0.4, 6.4). CBD was well tolerated, and rates of adverse events were similar between the CBD and placebo groups. Conclusions: These findings suggest that CBD has beneficial effects in patients with schizophrenia. As CBD’s effects do not appear to depend on dopamine receptor antagonism, this agent may represent a new class of treatment for the disorder." Herbivore's first cursory comments: This project appears to further vindicate what has already been demonstrated in pre-clinical and earlier phases of clinical trials. CBD appears to be an effective medication for the treatment of schizophrenia, one which is at least as well tolerated as other anti-psychotics currently used for this purpose. Crucially, this project found that even at 1g daily doses, there were no more adverse events experienced by patients who received CBD than by those in the placebo group, suggesting safety of CBD for this cohort. One limitation of this finding is that this study considered CBD alongside the patient's existing medications, and unless it is presented in the data supplement attached to this study, I am not sure that this study reported which medications were being taken. We cannot rule out that some, or even many of these patients may have been taking antipsychotics renowned for adverse side effects. In that case, no more adverse events for the CBD group than the placebo group could entail that the CBD group experienced adverse side effects similar to those of existing antipsychotics, which may or may not have been due to the CBD, their existing medications, or some interaction between the two. There is a lot of work to be done yet here! Of course, anecdotally, I am not aware of anybody experiencing adverse side effects from CBD as of yet. All we can take from this, strictly speaking, is that CBD does not appear to induce any worse side effects than other anti-psychotic medications. This project is not without other limitations also. The sample size (aka: number of participants) is somewhat small, even for a phase 2 trial. This means that the extrapolative potential of this study is limited, we cannot say that these results would certainly be replicated among others who suffer from schizophrenia. This is true of almost, if not all phase 2 clinical trials, we should remember that phase 2 trials are there to determine efficacy and side effects in a small cohort and do not seek to use a 'representative sample' that allows for extrapolation to all similar cases. It also should be considered that a number of the researchers involved in this multi-site project have variously worked in conjunction with, presented on behalf of, or received funding from companies (such as GW Pharma) that have financial interests in drugs containing CBD which may be subsequently used to treat patients with schizophrenia. What we need now are phase 3 trials with representative samples that allow for extrapolation to other cases, conducted independently by researchers who have no connection to organizations that may profit from medications containing CBD. These trials should include a placebo and CBD treatment groups that are not currently taking other anti-psychotic medications, potentially alongside those who are still taking their previously prescribed anti-psychotics. It is important to consider whether CBD is best used as an adjunct to existing medications, or may be used instead of them. One more factor to note is that this trial considered very large doses (1g per day) of CBD administered via an oral solution, this does not refer to inhaled medicine.