People who smoke cannabis heavily in their youth end up worse off than their parents both economically and socially, a new study finds.

The study doesn’t prove cause and effect, but it does suggest that people who do use marijuana on most days end up worse off than people who don’t — and it suggests that it’s not their family situation that’s causing their decline.

“Our study found that regular cannabis users experienced downward social mobility and more financial problems such as troubles with debt and cash flow than those who did not report such persistent use,” said Magdalena Cerdá at the University of California, Davis Health System, who led the study team.

“Regular long-term users also had more antisocial behaviors at work, such as stealing money or lying to get a job, and experienced more relationship problems, such as intimate partner violence and controlling abuse.”

The team studied people from Dunedin, New Zealand, who have been volunteering in a lifelong study since they were born in 1972 and 1973. More than 950 of the original 1,037 volunteers filled out questionnaires on marijuana use.