One of the biggest hangovers from the heavy-handed prohibition-era are the increasingly-redundant laws and regulations that were often built upon misinformation and outright fallacies.

The long-term impact on millions of casual users who found themselves at the mercy of draconian bill makers is something which can never be undone, but there is hope that the future could bring much brighter days. In order to punish anyone who dared dabble with 'The Devil's Lettuce', countless pieces of legislation were drafted up that outlined how people could be tested to prove that they had recently consumed cannabis or as a way of proving their levels of inebriation or impairment in relation to their perceived indiscretion. Sadly, what were often labeled as 'fair' legal limits of THC in the bloodstream or in hair follicles were so miniscule in reality that it had a knock-on effect not only when it came to dealing with law enforcement officials, but also when dealing with employers.

Countless cases of unfair arrests due to intoxication, dubious claims about the quantities in possession or situations attributed to being directly caused by cannabis consumption have been reported, with individuals often bearing the full brunt of the law for relatively minor issues. To make matters worse, some employers and larger-scale corporations use random drug testing to keep their workers in check, regardless of the fact that they are often singling people out who have done nothing wrong other than be associated with cannabis, often only as a casual user.The question of how long a user remains impaired after consuming cannabis has always been a tricky one to answer.

Not only have scientific minds found their areas of research to be incredibly limited in terms of scope and scale, but frequently there were issues surrounding the methods they were permitted to use or the strains they could include in their samples. Thankfully, the continued shift in the right direction means that we are now relying more on evidence-based studies as opposed to hypothetical predictions.Over the course of the past few years, a number of researchers have collated a wide range of available data in order to explore various aspects of our complex relationship with cannabis and the plethora of cannabinoids it contains. Of course, the main focus is often solely based around THC

levels, as it is deemed to be the most prevalent factor in creating the high, but the entourage effect and how it limits the impact of THC is also an area that is being considered and explored.By conducting a meta-analysis of around 80 papers, a team from the University of Sydney (USYD) set themselves the aim of clarifying the distinction between levels of THC in the body and the level of impairment that this produced.

One of the major driving forces behind this study is the need for "legal frameworks [to] catch up" with the data linked to the use of alcohol and its "focus on the interval when users are more of a risk to themselves and others," with Iain McGregor from USYD expressing that it was apparent that "THC can be detected in the body weeks after cannabis consumption, while it is clear that impairment lasts for a much shorter period of time."It is this comment in relation to a key misconception that makes this kind of study so important: all too frequently people are punished because of tests that prove they have THC in their system but with no concrete evidence of the time period since it had been consumed.

McGregor outlined his frustrations with this situation, explaining that any form of "prosecution solely on the basis of the presence of THC in blood or saliva is manifestly unjust."The various papers and the included data sets provided the team with more than 1,500  registered 'performance outcomes' of the people involved in the different studies. In essence, these outcomes were the result of tests that were conducted at various intervals after cannabis had been consumed.

Throughout the various testing stages and different research papers, the level of impairment was assessed through different tasks linked to cognitive function including driving simulations, tests of focus and memory games.Key findings from this study indicate that the level and longevity of a person's impairment is dependent on a number of factors. Different strains containing higher-or-lower levels of THC were found to increase or decrease not only the initial level of impairment but also how long it was likely to last. In addition, the methods of consumption were evaluated and it was found that oral consumption in the form of drops or edibles created the longest-lasting levels but would reduce the initial levels of impairment because it takes much longer to get into the system

Notably, there was also a clear correlation between the regularity of use in the individual and the levels of impairment they experienced. Most of the tests found that users were often impaired for anywhere between four and ten hours, depending on their preferred methods of consumption and pre-existing tolerance levels.The more casual or inexperienced user is much more likely to be notably impaired by cannabis use than a regular user and this also correlates with how long this might last. Once a level of tolerance has built-up, many users note that they don't feel 'as high' as they might do without consuming a higher quantity.

Moreover, each strain may have its estimated levels of cannabinoids but this is often dependent on various factors during the cultivation and curing process, meaning that it is very difficult to accurately predict how much of an impact consumption may have or how long the effects will last for general users.By using these findings as a catalyst for further research, the team hope to provide enough evidence to support the development of new legal frameworks that treat people fairly. While it has been shown that 'typical' impairment in relation to driving a vehicle is around the four-to-five-hour mark, this is still something that can vary greatly.

Their hope is to continue to provide evidence-based findings to those in positions of authority to ensure that laws take numerous factors into account and McGregor believes that, ultimately, "laws should be about safety on the roads, not arbitrary punishment." In many ways, this study will only serve to confirm what many cannabis users will have already come to learn from their own experiences.

However, anecdotal evidence is less impactful than real-life studies and this type of analysis has the potential to change perceptions of cannabis along with ensuring that people aren't unfairly reprimanded for its consumption. While some of us may not find much of this information to be revolutionary,  ground-breaking or life-changing in terms of developing our understanding of cannabis and its effects on us, it paves the way for more open conversations that should hopefully help to influence any future changes to the legal frameworks we all have to work within and around.