Dax Shepard was suspicious of Kristen Bell's "unbridled happiness" when they first met.

Dax Shepard and Kristen Bell

Dax Shepard and Kristen Bell

The 41-year-old actor - who has daughters Lincoln, three, and two Delta, with the 'Frozen' star - admits he was freaked out by the actress' outgoing personality and even thought she was a member of a cult when he first spoke to her in 2007.

He admitted to Good Housekeeping magazine: "When I met her and her friends, I was suspicious of their unbridled happiness.

"I thought, 'Something stinks here; they're in a cult.' "

Dax - who has been sober for 12 years - and Kristen, 36, credit therapy for their successful relationship.

The 'Employee of the Month' star said: "There were hurdles, things she didn't trust about me, things I didn't trust about her. I just kept going back to, 'This person has the thing I want, and I have to figure out how we can exist peacefully.' So we started [seeing a therapist together] right away."

His wife added: "You do better in the gym with a trainer; you don't figure out how to cook without reading a recipe. Therapy is not something to be embarrassed about."

Kristen previously revealed she has had to work hard at her marriage, which isn't always as perfect as it may seem.

She explained: "I need to remind people that you don't just find one person and then it's all peaches and cream for the rest of your life. Marriage and a relationship is hard work, and it's a lot of compromise. But if you compromise a lot, it's worth it."

And 'The Boss' star has learned a lot from her spouse's addiction problems.

She has said: "My husband is in recovery and is almost 13 years sober. And seeing the world through his eyes has really opened mine to knowing that it is a disease and nobody is choosing to drink more than others, they are doing it because of a variety of reasons and they deserve the attention of a mental health professional, and not the county jail or however else we're choosing to pretend we're fixing the problem."