Stonington— After a journey from hometown hero to junkie, Chris Herren is now in his 15th year of sobriety and sharing his story in the hopes of helping others.

That journey took him Thursday to Stonington High School, where the college star and former Boston Celtics player who lost his career and almost his life to drug abuse, spoke to students, faculty and town officials about the struggles of addiction and recovery.

Throughout his years in college and professional basketball, Herren, a native of Fall River, Mass., said he was given many chances, but he could not break the addiction cycle.

The high school basketball superstar became addicted to cocaine while in his first year playing for Boston College and was kicked out after three failed drug tests before the year ended. A second chance at California State University, Fresno, started out well, but a year on, another failed drug test saw him on national television admitting he was a drug addict and going to a rehabilitation program.

The 1999 second round NBA draft pick stayed sober while playing his first season for the Denver Nuggets but one summer break and OxyContin sent him spiraling again.

Being traded to the Celtics at the start of his second season should have been the pinnacle of his career — going back to his roots and playing for the team of his childhood idols — but instead, Herren said, it was overshadowed by his need for OxyContin.

Eventually, his OxyContin addiction turned into a heroin addiction, and he began stealing from family and friends and pawning anything of value, including his children’s belongings, to get money for drugs.

After 14 years of addiction, his fourth overdose, and the threat of divorce, Herren began his recovery for the final time on August 1, 2008. Since then, he has reached more than 2 million young people around the country through his visits to schools and started Herren Wellness in 2018, a holistic recovery organization.

Throughout his presentation, Herren, 48, kept returning to two central ideas: how people think of addiction and the reasons behind it.

He pointed out that when people think about drug addiction, they picture the addict’s worst day, when they should be thinking about the first day. He said that the scariest thing about drug addiction is there is no way to know who it will happen to, and nobody ever sees it coming, so it is essential to think about how it begins.

For Herren, it began with drinking beer and smoking marijuana in high school, and for years, he was able to hide his full-blown addiction, even from those closest to him.

He also continued to circle back to how people address addiction. He noted that when his substance use began, no one ever tried to understand or ask him why he was drinking or smoking marijuana.

He expressed gratitude that his two adult children never got involved in alcohol or drugs and attributed it to watching him battle addiction for so long. But he said if his youngest child did, his first reaction would not be to punish him. Instead, he said he would sit with his son, hug him, and say “let me understand why.”

For Herren, the “why” revolved around not liking the person he was and the person he was becoming. He progressed to cocaine, then OxyContin, and ultimately heroin, and the more he used, the less he liked who he was.

When a student asked if he still thinks about using heroin, Herren admitted he did, when he wasn’t feeling good about himself.

Junior Patrick McGugan said that Herren’s perspective on how he would handle his children experimenting with drugs and alcohol and the importance of asking why really made him think.

He was also struck by the raw honesty Herren displayed throughout the presentation, particularly Herren’s response when a student asked how to go about helping a friend who might be struggling with substance use or abuse.

“His response was he doesn’t fully know. He knows how to help from the counseling point of view, but as a friend, even he is still working to figure that out, which I thought was really powerful. We’re all still working on that,” McGugan said.

After the presentation, sophomore Rori Murphy said, “My biggest takeaway was that, even if they don’t say that they are struggling, they could be and everyone has to make sure they don’t make fun of each other for it.”

Herren’s visits to the middle school and high school Thursday were paid for jointly by the school district and the town using money received as part of a 2023 opioid settlement agreement between the federal government and more than a dozen corporations involved in the manufacture, sale and distribution of prescription painkillers.