Authorities said Al Gore III was driving a Toyota Prius at about 100 mph on the San Diego Freeway when he was pulled over around 2:15 a.m. Wednesday, Sheriff's Department spokesman Jim Amormino said.
The deputies said they smelled marijuana and searched the car, Amormino said. They found less than an ounce of marijuana along with Xanax, Valium, Vicodin and Adderall, which is used for attention deficit disorder, he said.
"He does not have a prescription for any of those drugs," Amormino said.
Gore III had been held in the men's central jail in Santa Ana on $20,000 bail.
The son of the former vice president and Democratic presidential nominee also was pulled over and arrested for pot possession in December 2003, in Bethesda, Md., while he was a student at Harvard University.
Gore was also ticketed shortly before the 2000 presidential election for driving 94 mph in North Carolina, CBS News correspondent Michelle Miller reports.
He completed substance abuse counseling as part of a pretrial diversion program to settle those charges.
The youngest of Al and Tipper Gore's four children and their only son, Gore lives in Los Angeles and is an associate publisher of GOOD, a magazine about philanthropy aimed at young people.
Meanwhile, former Vice President Al Gore said Thursday he's glad his son is safe and getting treatment.
"We love him very much," Gore told NBC's "Today" show, adding, "We are going to leave it as a private matter."
Photos: Celebrity Mug Shots
Gore appeared on NBC to publicize this weekend's Live Earth concerts.
Gore also briefly discussed politics. He called President Bush's decision to commute the perjury and obstruction of justice sentence of former White House aide I. Lewis "Scooter" Libby "disappointing" and reiterated that he has no plans to run for president, saying: "I don't expect to be a candidate again ever."
"I've kind of fallen out of love with politics," Gore said. He said the best use of his experience is to bring awareness and a sense of urgency to the issue of climate change.
Gore laughed when asked if he was ready to endorse a candidate for president. He said his evaluation would be based on what each decides to do about climate change.
"Some of them have made good, positive statements, but it's still treated as a side issue. I will predict for you that within the next 500 days that this issue will be the Number One issue on the agenda," he said.