The upcoming season will reportedly focus on Matt Brown's journey through rehab, which the family announced last month.
On Sunday's season 8 finale, the 36-year-old seemed distressed and wanted to be on his own. A source told Radar that he had already relapsed when the footage for the finale was shot.
It won't be Brown's first time seeking help for his alcohol addiction. In 2016, he checked into treatment after being arrested for DUI in Juneau, Alaska. After that successful stint, he started drinking again to cope with his mother being diagnosed with lung cancer.
Brown told PEOPLE that he made the decision to return to rehab after a series of "ups and downs."
"I struggle with substance abuse, and after a year of ups and downs, I decided to return to treatment," he said. "I'm really grateful for everyone's support and hope to have my life back on track soon."
Despite his absence from the family's new home in Washington state, the rest of the Browns are giving their full support.
"It's hard not having one of my babies here with us," Ami said. "He was so strong for me, and I want to be strong for him."
Patriarch Billy Brown added that the family misses "him terribly, but we'd rather lose him from home for a little while than lose him forever. We just want him to do what he needs to do to get better."
Brown opened up about his struggle with alcohol addiction and his previous DUI, admitting to PEOPLE that the issue began when the family boat broke down and they began spending time in the nearby city of Juneau.
"I've always been able to handle city life, no problem. But I started hanging out with people who drank. They didn't have a problem with it so while I was around them, I started drinking," he said.
He said that while the drinking started out casual, "it got to be more and more" and made him "withdrawn," slower and making life less exciting than before.
He said that after he "could see myself spiraling" he realized he "didn't want to be one of those guys" and entered an in-patient rehab center for 35 days, where he came to the conclusion that he was not an alcoholic but did have a tendency to abuse alcohol.
"I learned a lot about myself in those 35 days. I've turned my weakness into a strength," he said. "In life, we all get lost every now and then and have to find our way back. Not everyone makes it back, and I'm happy to be one of those who did."