The couple has only been married for 15 months

Kate Walsh doesn't only have marital problems on TV.

The "Private Practice" star's husband, Alex Young, has filed for divorce, reports "Entertainment Tonight."

According to court papers, the couple has been separated since Nov. 22, just before Thanksgiving. Young cites irreconcilable differences as the reason for the split.

Walsh, 41, and 37-year-old Young, a production co-president at 20th Century Fox, in February 2007, and he proposed three months later. They had gone public with their romance in April at a Los Angeles fundraiser for the now president-elect Barack Obama.

The couple tied the knot in September 2007 in Ojai, Calif. The ceremony was attended by friends, family, actress Kate Beckinsale and her director husband Len Wiseman, as well as "Grey's Anatomy" costars Katherine Heigl, Chandra Wilson, Sara Ramirez and Justin Chambers.

Walsh first played Dr. Addison Montgomery on "Grey's Anatomy" before spinning off to her own series, "Private Practice," both on ABC.