Australian scientists have found preliminary evidence that cannabis use alters the way people walk. Their findings were published in the journal Drug and Alcohol Dependence.

“Cannabis is the most widely used illicit drug, with 35% of Australians aged 14 years and over reporting use on at least one occasion,” said Verity Pearson-Dennett of the University of South Australia, the study’s corresponding author.

“Most of the research on illicit drug use focuses on long-term changes in cognition and psychological well-being,” he explained. “Illicit drugs exert their effects by changing the levels of neurotransmitters in the ‘pleasure centers’ of the brain, but these neurotransmitters are also very important in movement.”

“It is therefore possible that these drugs may impact the way we move. It is important to fully understand the long-term effects of cannabis use, particularly given the move to decriminalize use in many countries and the growing tolerance to use of cannabis.”

The researchers compared 22 cannabis users to 22 non-drug using Australians. The cannabis users had consumed the drug on more than five occasions and had no history of illicit stimulant or opioid use.

The researchers found subtle differences in how each group walked. Cannabis users moved their knees faster when swinging their leg forward to walk, but tended to move their shoulders less. The researchers found no difference in walking speed or balance.

“The main take away message is that use of cannabis can result in subtle changes in the way that you move,” Pearson-Dennett told PsyPost. “The changes in walking were small enough that a neurologist specializing in movement disorders was not able to detect changes in all of the cannabis users. However, many of the participants in the cannabis group were moderate-to-light cannabis users, therefore heavier cannabis users may have greater impairments.

One of the main limitation of the study is its small sample size.

“This was a small pilot study, therefore a number of questions need to be addressed,” Pearson-Dennett explained. “For example, does a greater amount of cannabis use mean a greater level of impairment? Does the strain or THC/CBD content of the cannabis used change the level of impairment observed? In addition, the physiological mechanisms that underpin changes in movement are not well understood.”

The study, “History of cannabis use is associated with altered gait“, was also co-authored by Gabrielle Todd, Robert A. Wilcox, Adam P. Vogel, Jason M. White, and Dominic Thewlis.