(Newswire.net — December 11, 2018) — New tests point to a link between cannabidol (CBD), a substance found in cannabis, and typical antidepressant effects. The relationship was substantiated in a rodent study published in the journal Molecular Neurobiology. These effects in rodents were significant and sustained, with increased antidepressant effects noted for a whole week after one single administration.
Mice, in this study, were found to show improved resilience according to a stress-based model of depression. This was noted just one hour after the introduction of CBD, potentially making the substance a faster-acting antidepressant than some existing alternatives.
To accurately measure the effects of CBD, it is always crucial for experimenters to have an accurate technological means of tracking rodent behavior and a high-quality space for testing. This is particularly the case when performing any tests which monitor depression levels, as the determining variable in rodents is often associated with movement. Depressed rodents are more likely to spend time away from other rodents, and show less interest in socialization. They are also more likely to give up easily on physically demanding activities and show reduced discrimination between a usually-preferred sucrose solution, and plain water.
As a result, studies such as the above have benefitted from tracking technologies such as the SmartCage. This is an automated system which allows for multiple facets of rodent monitoring, from drug screening to general cage activity. For example, if testing the effect of a new antidepressant on rodents, it would be telling to monitor how much time the implicated rodent spends in physical contact with other rodents before and after the substance is administered.
One of the tests also employed in the Molecular Neurobiology rodent study is named the ‘forced swim test’. This is a method of measuring resilience in rodents, as they are placed in a cylinder of water and observed. In theory, more depressed rodents will more quickly give up on trying to escape the water.
To gain accurate results from the forced swim test, it is important to label states of mobility and immobility in the water as reliably as possible. This is where other technology sets in. As well as providing a swim cylinder, technologies can offer solutions to incorporate video footage with behavioral scoring, for the most accurate analyses. They can be used to automatically track floating, swimming, and climbing/escaping behaviors. This makes the forced swim test a viable method of measuring rodent depression levels.
Clearly, the rise in technology available when testing rodents means that significant findings such as that of CBD and its antidepressant qualities should not be discounted. It is likely that the rodents were tested in a very reliable way.
While proposing to treat human depression with a substance found in cannabis may raise eyebrows, it has been shown that CBD is a non-psychoactive part of the cannabis plant. This means that it has the potential to treat depression without any of the risks typically associated with taking cannabis.
Studies such as the 2016 effort made by Sartim, Guimaraes, and Joca have attempted to delve deeper into the identification of the neural pathways acted upon by CBD when inducing antidepressant qualities. It was stated that the ventromedial prefrontal cortex (vmPFC) and 5-HT1A receptors are highly implicated in rodents, but many more human tests must be completed before CBD can be considered a viable treatment for depression.
A 2018 study by Sales et al has also demonstrated a large role for the hormone serotonin. Their results suggest that CBD works alongside serotonin, to reduce the amount of the hormone required for antidepressant effects to take place. This would mean that those suffering depression could be able to receive smaller doses of medication, meaning less risk of side effects.