All posts by Dr Adrian Lopresti
The Problem of Placebo Responses in Clinical Trials and How To Combat Them
Randomised controlled, double-blind trials are considered gold-standard study designs. In these studies, the active intervention is often compared to a placebo condition. Ideally, in pharmaceutical and nutraceutical/herbal trials, these placebos are matched for appearance, smell, and taste. A common phenomenon occurring in such gold-standard studies is the ‘placebo response’. This is where participants are placed […]
Continue readingHow to Determine the “Value of an Intervention”
Why p-values, effect sizes, and clinically meaningful change are not enough When clinical trials are conducted, significance values are generally set at a p-value of 0.05. This means there is less than a 5 percent chance that the finding occurred by chance. Criticisms associated with this approach are that even though the finding was statistically […]
Continue readingWhat Should We Be Doing to Improve Treatment Outcomes for Depression?
Estimates of the prevalence of depression can vary, but it seems that approximately 20% of people will experience a depressive episode sometime in their life. This rate refers to a diagnosed DSM-5 depressive episode [1]. However, not everyone will meet the criteria for a major depressive disorder, so when we consider bouts of significant sadness […]
Continue readingThe Increasing Problem of Borrowed Science in Herbal and Plant-Based Medicine
Research into herbal and plant-based medicine is increasing. If I quickly search in PubMed using the terms herbal and plant for clinical trials conducted in 2022, 892 published results appear. This is exciting news because although traditional knowledge and practices are important, robust clinical trials must be performed on natural ingredients to support and expand […]
Continue readingOptions to Accurately Measure the Body’s Stress Response
The hypothalamus-pituitary-adrenal (HPA) axis is a biological system involved in our stress response. In response to stress (physical, mental, real, or imagined), the hypothalamus releases corticotrophin-releasing hormone (CRH), which then triggers the pituitary gland to release adrenocorticotropic hormone (ACTH), which in turn activates the adrenal cortex to release cortisol. When the system works well, a […]
Continue readingStatistical significance versus clinically meaningful in interventional trials
In clinical trials, researchers use statistical significance to determine whether an intervention is effective. Typically, if the p-value is less than 0.05, the intervention is considered effective. Statistical significance is often criticised because while an intervention may have statistical significance, it may not lead to ‘meaningful’ improvements. For example, the intervention may improve symptoms by […]
Continue readingAssay Sensitivity and Clinical Trials
When designing clinical trials, the study design must be robust. Decisions around the sample size, treatment duration, eligibility criteria, and randomisation and blinding must be made. In addition to all these factors, assay sensitivity must be considered. Assay sensitivity refers to the trial’s ability to distinguish an effective treatment from a less effective (or ineffective) […]
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