As marijuana legalization spreads, a new study says that teenage marijuana use can lead to some devastating consequences down the line.

Published in JAMA Health Forum, the research tracked nearly 460,000 adolescents in Northern California’s Kaiser Permanente health system through age 25. Led by Dr. Kelly Young-Wolff of the Kaiser Permanente Research Institute, the team excluded teens who already showed signs of mental illness. The team set out to answer a single question: If otherwise healthy teens use cannabis, are they more likely to develop psychiatric disorders later?

That answer appears to be yes.

Teens who reported using cannabis in the past year faced roughly double the risk of being diagnosed with bipolar disorder or a psychotic disorder, including schizophrenia. All of which are among some of the most debilitating psychiatric conditions. Though only about 4,000 teens developed each disorder, the consequences will stretch out for the duration of their lives and touch every aspect of their lives. On a societal level, schizophrenia alone has been known to collectively cost about $350 billion annually.

Depression rates rose by about a third among cannabis-using teens, and anxiety increased by roughly a quarter. The younger the teenager, the stronger the link. Since adolescent brains are still under construction, cannabis interacts with neural receptors involved in development and potentially alters trajectories in ways that won’t show up until years later.

Mental illness is a complex subject loaded with nuance and textures, often shaped by a myriad of factors like genetics, environment, and personal experience. Blaming teenage cannabis use solely is misguided and just flat out wrong. But this study strengthens the evidence that, for some teens, it may act as an accelerant of already-existing problems.

The road to widespread cannabis acceptance throughout the country was fraught with too many battles to recount. But now that the war has largely been won, it’s time to trust legitimate scientific research to reassess what it means to be a society that has incorporated weed into its day-to-day. Part of that means reckoning with what it does to developing brains, which we’re only now beginning to understand.