"I recently completed an out of state private intensive program," he wrote on his Twitter account. "I will continue to tackle this going forward with my doctors, family and friends. I am so very thankful for all of the support I've received."
Woods said he had a problem managing his medications that were used for back pain and to help him sleep.
The issue came to light in May when he was arrested for driving under the influence. Police said alcohol was not involved, and Woods later explained that he had "an unexpected reaction to prescribed medications," per Kristina Sgueglia and Jill Martin of CNN.com.
The 41-year-old golfer underwent fusion surgery on his back in April to provide relief for nerve pain, the latest in a long line of surgeries and other treatments for his ailing back.
Various issues have kept him away from golf over the past few years, and he has only appeared in three events since the start of 2016. His last competitive round came at the Omega Dubai Desert Classic in February 2017, although he was later forced to withdraw.
Although his injuries could continue to be a problem for the 14-time major champion, his problems with medication are hopefully a thing of the past.