Introduction
Searching for and developing alternative and effective methods for treating such a complicated disease as schizophrenia is the primary task of many medical scholars and organizations. In this regard, randomized controlled trials (RCT) are an integral scientific instrument that can assess the effectiveness of a new treatment by examining cause-effect relationships between an implemented intervention and outcome with reduced biases. This paper aims to analyze the article “Cannabidiol (CBD) as an adjunctive therapy in schizophrenia: A multicenter randomized controlled trial” by McGuire et al. (2018), primarily focusing on the statistical aspect.
Criticism
The objective of the study is to evaluate the effectiveness and safety application of cannabidiol (CBD) as an adjunctive treatment for patients with schizophrenia. The researchers have explored CBD’s impact on cognitive performance, positive and negative psychotic signs, level of functioning, and the overall clinical impression of treating a psychiatrist. In a randomized, double-blind, placebo-controlled, parallel-group trial, participants who had partly responded to antipsychotic medication obtained either CBD or placebo as an auxiliary intervention for six weeks.
The number of participants, age structure, gender, race, the dose of received cannabidiol, the patients’ weight, height, waist circumference, and body mass index can be classified as independent variables. Herewith, the number of participants is a quantitative or discrete type of variable, gender is a binary variable, age structure belongs to the continuous type, and other variables are categorical. Symptom severity, cognitive performance, functioning level, and adverse events belong to dependent variables of categorical, ordinal type. The authors utilized descriptive and inferential statistics to describe input information and data retrieved from the findings. For example, the sample size includes 88 patients who met the inclusion criteria, of which 51 were male. Besides, 82 were white or Caucasian, three were black, and three – were from other races. The mean age accounted for 40.8 with a standard deviation (SD) – of 11.69, while BMI was 28.4 with an SD – of 5.35 (McGuire et al., 2018, p. 227).
Using the Positive and Negative Syndrome Scale (PANSS), the researchers also analyzed the alterations in symptom severity from baseline to the treatment end. Specifically, in the cannabidiol group (N=42), the mean of change from baseline score comprised –11.2 with SD – 7.87, whereas, in the placebo group (N=44), the mean amounted to –8.8 with SD – 8.87. Hence, the treatment difference between the groups consisted of –2.8 with a p-value of – 0.133 (McGuire et al., 2018, p. 228). Similar measures for general functioning, symptoms, extrapyramidal signs, cognitive performance were conducted, and the most frequent adverse events were identified.
In conclusion, the article revealed the beneficial effect of CBD on patients with schizophrenia. In addition, the researchers specify that due to the independence of CBD from dopamine receptor antagonism, the substance can become a new class of treatment for the condition.
Reference
McGuire, P., Robson, P., Cubala, W. J., Vasile, D., Morrison, P. D., Barron, R., Taylor, A. & Wright, S. (2018). Cannabidiol (CBD) as an adjunctive therapy in schizophrenia: A multicenter randomized controlled trial. American Journal of Psychiatry, 175(3), 225-231.