Police are searching for the 42-year-old actor who was last seen in Vancouver on Feb. 14th. Koenig's family said he went to visit friends in Toronto before traveling to Vancouver, where he had lived for several years.
Walter Koenig says his son suffers from depression, and seemed despondent in a text message he received from Andrew on Feb. 9th.
"I think it's something that has been a part of his makeup for a long time. There's no single trauma. There's no episode. There's nothing of that nature," Walter told People.com, who added that drugs were not an issue.
Celebrities including Alyssa Milano, Sara Silverman and "Best Week Ever's" Doug Benson have reportedly been on Twitter and on blogs, urging people to keep their eyes open.
Koenig had recently finished shooting a trailer for a feature film that he wanted to direct. His parents also say he is an outspoken environmentalist and human rights activist.
Anyone with information to contact the Vancouver investigators at (604) 717-2534.