A 320-page lawsuit filed Monday takes aim at companies that sell legal marijuana in Illinois and many other states, claiming they have not told customers the possible mental health implications of cannabis use while claiming it has curative effects for other ailments.

The suit was filed in federal court in the Northern District of Illinois by – among other law firms – those of Pat Kenneally, the Republican former McHenry County state’s attorney, and Jack Franks, a Democratic former Illinois lawmaker and one-term McHenry County Board chairman. Both are now in private practice.

The suit also was filed in downstate Madison County, as well as in Connecticut courts, lawyers said.

The suit, which would need to be certified by courts as a class action, was filed on behalf of 40 named plaintiffs who bought cannabis in these legal states and say they were not warned about the mental health risks.

The other states are Arizona, Connecticut, Maryland, Massachusetts, Michigan, Minnesota, Nevada, New Jersey, New York, Ohio, Rhode Island and Virginia.

The marijuana companies “market and promote their cannabis products to an unsuspecting public through a public relations megaphone as the antidote to ailments of all kinds, including, among others, insomnia, narcolepsy, over-eating, cancer, auto-immune disorders, neuropathy, pain, anger, boredom, sadness, shyness, irritable bowel syndrome, grief and opioid addiction. These claims are part of a calculated strategy,” the suit claims, adding that defendants Cresco Labs, Green Cresco Labs, Green Thumb, Verano Holdings and Verano LLC “have unleashed an acute intoxicant” in THC, a main ingredient in cannabis, at unprecedented concentrations.

The defendants, the suit claims, should know that medical research shows marijuana use “causes and exacerbates development of schizophrenia, psychosis, bipolar disorder, suicidal ideation, depression, and anxiety, and other serious health disorders.”

This is not the first time that Kenneally has taken aim at marijuana retailers. In August 2023, when he was the county’s top prosecutor, he required McHenry County dispensaries to post signage with mental health warnings or face lawsuits.

The suit is not trying to shut down marijuana dispensaries, Franks said Monday, but to require retailers to warn users of the possible dangers.

“They can’t call it medicine. They are not pharmacists,” Franks said, adding no research shows marijuana has effects on any ailment.

There are two FDA-approved drugs made from synthetic THC, one for cancer patients and one for HIV patients, and a CBD-based treatment for epilepsy.

But there is no evidence that indicates marijuana has other benefits for a list of illnesses, Franks said.

“They can’t make the claim when the research hasn’t been done on it,” Franks said.

Reached Monday via email, a Cresco spokesperson replied, “As a matter of policy, Cresco Labs does not comment on threatened or active litigation.”

A representative from a PR firm working with Green Thumb said they were unaware of the lawsuit. No one from Verano could be reached for comment.

Recreational marijuana sold in Illinois carries a label reading: “Smoking is hazardous to your health. This product contains cannabis and is intended for use by adults 21 and over. Its use can impair cognition and may be habit-forming. This product should not be used by pregnant or breastfeeding women. It is unlawful to sell or provide this item to any individual, and it may not be transported outside the State of Illinois. It is illegal to operate a motor vehicle while under the influence of cannabis. Possession or use of this product may carry significant legal penalties in some jurisdictions and under federal law.”

But the lawsuit argues that these health warnings are not detailed enough and fail to communicate the more serious mental health risks like psychosis, anxiety and schizophrenia.

The lawsuit also asserts that even if the cannabis companies avoided explicit medical claims, their marketing still created a misleading impression that cannabis is considered safe and therapeutic.

Illinois does not allow cannabis companies to market like medical products and has key restrictions in the Cannabis Regulation and Tax Act, including:

• No false or misleading advertising.

• No claims implying FDA-approved medical treatment.

• No endorsement-style marketing suggesting state approval.

• Marketing cannot target minors.

• Companies can describe product characteristics like “calming,” “energizing” in general terms, but can’t legally claim cannabis treats or cures diseases.