A case that will determine whether Missouri can continue restricting adolescents’ access to gender-affirming care began Monday in Cole County Circuit Court.

The plaintiffs — which include transgender minors, gender-affirming care providers and loved ones — will argue that medical treatments for gender dysphoria are “safe and effective,” attorney Omar Gonzalez Pagan said in opening arguments.

The state will defend the 2023 law restricting gender-affirming care by looking into the risks of the treatment and highlighting those who have regretted medical transitions.

“These kids need compassionate, evidence-based medicine. But what they’ve been doing for the past 15 years isn’t evidence-based,” Solicitor General Joshua Divine said in his opening statement.

Defendants include Gov. Mike Parson, who signed the bill into law, and Attorney General Andrew Bailey, who is responsible for enforcing the law.

Both parties plan to call a host of expert and fact witnesses, and attorneys have requested a week for each side to present evidence.

On the first day of the trial, which will be heard by Circuit Judge Craig Carter without a jury, attorneys argued over which experts were most qualified to speak on the efficacy and risks of gender-affirming care.

“(Plaintiffs’ experts) are the type of people that are qualified to testify as to this type of care,” Gonzalez Pagan said. “The state’s experts, with one exception, do not have this sort of experience.”

Divine said that plaintiffs’ experts benefit financially from gender-affirming care, so they have their “financial reputations” at stake. He defended his witnesses’ qualifications, calling one a “victim of cancel culture” when a journal article was retracted.

The first expert called to testify was Dr. Aron Janssen, vice chair of clinical affairs at the Pritzker Department of Psychiatry and Behavioral Health at Lurie Children’s Hospital in Chicago. A majority of the patients in his psychiatry practice are transgender or gender-nonconforming children and adolescents, he said, and he has published approximately 24 articles in academic journals.

Jason Orr, an attorney for the plaintiffs, asked him about the state’s claims.

One claim is that gender dysphoria is a self-diagnosed condition because the symptoms are self-reported. Janssen said physicians base a diagnosis on questions to patients and loved ones, like other psychiatric conditions he treats.

“If that was a standard to base diagnosis, we wouldn’t have depression, anxiety, migraines,” he said.

The state will bring “detransitioners,” or people who began transitioning to a gender other than their sex as assigned at birth and later stopped. One received gender-affirming care in Missouri as an adult, but none received the care as a minor in Missouri, attorneys discussed in a virtual hearing last Friday.

Orr asked Janssen if there’s any scientific literature about those who stop their transition.

“The majority of patients who detransition do so because of external pressures but not because of internal pressures or regret,” Janssen said. “For some, transition is a wonderful experience… For others, it means you are kicked out of your family, lose your job.”

Patrick Sullivan, with the attorney general’s office, used several documents to challenge Janssen during cross-examination. Some were not on the list of items the defense plans to submit as evidence, but Carter allowed the exhibits for questions only.

Some of the documents were studies, including the over 400-page Cass Review published earlier this year. The report was a systematic review commissioned in England that concluded that there was weak evidence to support cross-sex hormones and puberty blockers for transgender youth.

Sullivan presented Janssen a document called an “evidence pyramid,” with systematic reviews at the top as the best form of scientific literature.

Janssen said the Cass Review had a key flaw: the authors are not experienced in gender-affirming care and wouldn’t know the best factors to look at.

“When we look at what is involved in creating a good systematic review, having experience in the field is important,” he said. “When none of the authors work in the area, we have to take what they’re saying with a grain of salt.”

Sullivan interrupted him as Janssen explained the review’s flaws.

“He’s answering your question,” Carter said.

Sullivan’s questioning lasted around two hours, with multiple objections from plaintiffs as new exhibits came into the courtroom. The exhibits were largely studies out of Europe and articles from The New York Times and The Free Press.

Sullivan used an opinion article to question plaintiffs’ second expert, a clinical child psychologist.

The other witness to take the stand during the trial’s premiere day was a transgender man who transitioned at a young age in Missouri.

Arguments are scheduled to conclude Oct. 4.