Tougher cannabis laws impact occasional users but not frequent drug takers

'Results suggest that although diffused availability may be affected by some forms of restrictive governmental measures, the latter have no effect on the supply networks which are presumably well established for those social groups which have a high frequency of use.' Picture: AP Photo/Franka Bruns

European studies suggest tougher sanctions may reduce cannabis use among experimental or occasional adolescent users, but do not seem to affect frequent users, an international drugs conference in Dublin has heard.

The National Drugs Forum 2022, which attracted speakers from across Europe and Ireland, was told actions of governments appear not to impact cannabis supply networks, which are thought to be more focused on frequent users.

Speaking at the event, Sabrina Molinaro of the National Research Council of Italy examined research on how changes in policy in Europe affected adolescent cannabis use.

“Results suggest that although diffused availability may be affected by some forms of restrictive governmental measures, the latter have no effect on the supply networks which are presumably well established for those social groups which have a high frequency of use,” she said.

“Selected policies do have an impact on the prevalence of experimentation and non-frequent users, with those depenalising cannabis possession increasing it and those raising penalties causing a reduction.” 

Ms Molinaro, who is research director at the Institute of Clinical Physiology at the centre, said this impact did not carry over to those who use cannabis more often.

No type of reform seems able to reduce the proportion of those adolescents that due to their high frequency of use are more at risk of experiencing related harms and more likely to use the drug for longer in adulthood.” 

Referencing a study from 2021, Ms Molinaro said some forms of liberalisation, for example in the Czech Republic, are associated with an increase in cannabis use.

She said some reforms that have provided for an increase in sanctions, for example in Italy, are associated with a decrease in both perceived availability and some prevalence of consumption.

But no reform is associated with a decrease in the frequent use of cannabis or in the perception of the availability of the substance by regular users.

The forum was organised by the Department of Health and the Health Research Board.

Prevention programmes

In terms of policy lessons, Ms Molinaro said any cannabis control policy should be accompanied by investment in adolescent substance use prevention programmes that were based on evidence.

To be effective, these might possibly target resilience factors in order to increase the unwillingness to use the drug, even when actual opportunities to do so are available.” 

Examining research from the four-yearly ESPAD study of schoolchildren, Ms Molinaro said “high risk” cannabis use ran, on average, at 4% across participating countries, with Ireland, Spain and Netherlands above average (5-6%) and rates in Germany, France, Italy and Central Europe above 6%.

HRB researcher Ena Lynn said drugs data was “dominated by men” and said issues faced specifically by women may be masked.

She said the majority of drug-related deaths among women involved prescribed drugs.

Andy O’Hara of service user group UISCE told the forum that people who use drugs should be treated as experts in terms of those with lived experience and said they should inform policy and practice.