Showtime Canceling United States of Tara

United States of Tara's third season will be its last.

The Showtime series has seen its ratings fall with each successive season. Including multiple showings, DVR playback and video-on-demand, it's averaged about 1.9 million viewers this season, down 30 percent.

Toni Collette welcomes a boy

The show netted star Toni Collette two Emmy nominations and one win. She also picked up a Golden Globe and was nominated for a SAG Award for her portrayal of Tara Gregson, a wife and mother who's been diagnosed with multiple personality disorder.

Meantime, Nurse Jackie has been picked up for a fourth season.