Lamar Odom and Khloé Kardashian
Splash News Online
12/13/2013 at 12:00 PM EST
Four years after their televised whirlwind marriage
, reality, sadly, has hit home.
has filed for divorce from Lamar Odom in Los Angeles Superior Court, PEOPLE has confirmed.
The news comes after months of speculation that Lamar's substance-abuse issues
– which led to a DUI arrest
in August and a stint in rehab
shortly after – have put an irrevocable strain on the couple's marriage.
Reports that the couple had been living apart
surfaced in September after Khloé 29, and Lamar, 34, who married in a lavish 2009 ceremony, had not been publicly seen together in weeks.
Following Lamar's rehab stint, the couple were spotted attending
a Kanye West
concert together in Los Angeles in late October, where the pair sat next to each other in the VIP section and were joined by other members of the Kardashian-Jenner family.
Still, the sighting didn't quell speculation that the two were struggling to keep their marriage together. In mid-November, an insider confirmed to PEOPLE that the two were in couples therapy
– but sources close to Khloé said the reality star seemed long resigned that her marriage may soon be over.
"It doesn't seem like a reconciliation is any closer to happening," a source revealed.
"It's like the situation is just too far gone at this point for a split to be anything but unavoidable."
Added another source: "She just doesn't know if she can work this out."
On Wednesday, Khloé stepped out to attend the Hollywood Reporter
's Women in Entertainment Breakfast in Beverly Hills, where she was spotted without her wedding ring.
Odom, who received three years' probation
after reaching a plea bargain in his DUI case, has a history of drug-related incidents
and had been dogged with relapse rumors since August.