Lea Michele is "much less miserable" now she is dating Cory Monteith.

The two stars appear in US TV show Glee, where their characters are romantically involved.

There have been rumours the pair are more than just good friends in real life too and it is thought they officially began dating last month.

Lea split from Broadway star Theo Stockman in September last year after the pressures of a long-distance romance grew too much. Finding love with Cory is said to have revived her.

"Cory is definitely having a positive effect on Lea. She's much less miserable these days," an insider told Us Weekly. "Even when she was with Theo, she was always depressed being so far away from him and not getting to see him. She likes having someone with her that's actually there. Long distance is not her thing."

Last weekend, Lea, 25, and 29-year-old Cory were spotted out and about in New York City together. The pair apparently decided to get away from the stresses of their hectic schedules for a relaxing mini-break.

"They had a great little quick trip in New York," the source explained. "Lea didn't want to be away from him for just those few days."

Lea portrays Rachel Berry in Glee, while Cory is Finn Hudson.