Stanton "Larry" Stein told People magazine exclusively that Duchovny has entered a rehabilitation facility to address the issue.
The 48-year-old actor is best known for his work on the TV shows "The X-Files" and "Californication." He has been married to actress Tea Leoni for more than a decade and the couple are the parents of two young children.
"I have voluntarily entered a facility for the treatment of sex addiction," Duchovny said in an exclusive statement issued to People. "I ask for respect and privacy for my wife and children as we deal with this situation as a family."