As cannabis potency in products increased over the years, so have rates of people suffering from cannabis addiction, a new study found.

A team of researchers from the Addiction and Mental Health Group at the University of Bath (U.K.) systematically analyzed the relationship between the kinds of cannabis people use and their addiction and mental health problems.

Using 20 studies involving almost 120,000 people, the researchers found that people who use high-potency cannabis are more likely to experience addiction than those who use low-potency products. The researchers also found that people who use high-potency cannabis have a higher likelihood of experiencing psychotic disorders, such as schizophrenia.

With their findings recently published in The Lancet Psychiatry, the new study may help explain why more people have received treatment for cannabis-related problems in recent years. Data from the European Monitoring Centre for Drugs and Drug Addiction showed a significant increase in people entering treatment for cannabis addiction.

Based on the findings, the researchers argued that there should be more public health guidelines and policies for safer cannabis use.

"Our systematic review found that people who use higher-potency cannabis could be at increased risk of addiction as well as psychosis when compared to people who use cannabis products with lower potencies,” explained lead author Kat Petrilli, from the University of Bath's Department of Psychology.

“These results are important in the context of harm reduction, which aims to minimize the negative consequences associated with drug use. While the safest level of use for cannabis is of course 'no use,' it is important to acknowledge that a significant number of people across the world use cannabis regularly, and to ensure they can make informed decisions that could reduce any possible harms associated with it."

The authors also pointed out that strategies encouraging safer cannabis use could help decide how the drug should be regulated in the U.K. and international market.

The authors noted that the links between cannabis potency and other mental health problems are still unclear, but anecdotal evidence showed a relationship between the drug and anxiety and depression.