LOS ANGELES — Adam Mosseri, the chief of Instagram under Meta Platforms, took the stand on Wednesday during a pivotal social media trial in Los Angeles, expressing his disagreement with the notion that individuals can develop clinical addictions to social media platforms.

The concept of addiction is central to this case, which aims to hold social media companies accountable for potential harm to children using their platforms. Currently, Meta Platforms and Google’s YouTube remain as defendants, while TikTok and Snap have already reached settlements.

This trial features a 20-year-old plaintiff, identified only as “KGM,” whose lawsuit could set a precedent for thousands of similar cases against social media giants. Alongside two other plaintiffs, she has been chosen for bellwether trials, serving as test cases to gauge the strength of arguments before a jury.

Since taking the helm of Instagram in 2018, Mosseri has emphasized the need to distinguish between clinical addiction and what he terms “problematic use.” The plaintiff’s attorney highlighted Mosseri’s past comments from a podcast, where he had used the term “addiction” in relation to social media. Mosseri clarified his earlier remarks, acknowledging that he may have used the term “too casually,” a common tendency.

When questioned about his expertise to comment on social media addiction, Mosseri noted he is not a medical professional. However, he mentioned having a close acquaintance who has dealt with severe clinical addiction, underscoring his cautious choice of words.

Mosseri explained that within his team, “problematic use” describes scenarios where individuals spend more time on Instagram than they are comfortable with, acknowledging that such instances do occur.

It’s “not good for the company, over the long run, to make decisions that profit for us but are poor for people’s well-being,” Mosseri said.

Mosseri and the plaintiff’s lawyer, Mark Lanier, engaged in a lengthy back-and-forth about cosmetic filters on Instagram that changed people’s appearance in a way that seemed to promote plastic surgery.

“We are trying to be as safe as possible but also censor as little as possible,” Mosseri said.

In the courtroom, bereaved parents of children who have had social media struggles seemed visibly upset during a discussion around body dysmorphia and cosmetic filters. Meta shut down all third-party augmented reality filters in January 2025. The judge made an announcement to members of the public on Wednesday after the displays of emotion, reminding them not to make any indication of agreement or disagreement with testimony, saying that it would be “improper to indicate some position.”

During cross-examination, Mosseri and Meta lawyer Phyllis Jones tried to reframe the idea that Lanier was suggesting in his questioning that the company is looking to profit off of teens specifically.

Mosseri said Instagram makes “less money from teens than from any other demographic on the app,” noting that teens don’t tend to click on ads and many don’t have disposable income that they spend on products from ads they receive. During his opportunity to question Mosseri for a second time, Lanier was quick to point to research that shows people who join social media platforms at a young age are more likely to stay on the platforms longer, which he said makes teen users prime for meaningful long-term profit.

“Often people try to frame things as you either prioritize safety or you prioritize revenue,” Mosseri said. “It’s really hard to imagine any instance where prioritizing safety isn’t good for revenue.”

Meta CEO Mark Zuckerberg is expected to take the stand next week.

In recent years, Instagram has added a slew of features and tools it says have made the platform safer for young people. But this does not always work. A report last year, for instance, found that teen accounts researchers created were recommended age-inappropriate sexual content, including “graphic sexual descriptions, the use of cartoons to describe demeaning sexual acts, and brief displays of nudity.”

In addition, Instagram also recommended a “range of self-harm, self-injury, and body image content” on teen accounts that the report says “would be reasonably likely to result in adverse impacts for young people, including teenagers experiencing poor mental health, or self-harm and suicidal ideation and behaviors.” Meta called the report “misleading, dangerously speculative” and said it misrepresents its efforts on teen safety.

Meta is also facing a separate trial in New Mexico that began this week.