In 1988, Back to the Future star Michael J. Fox vowed to stay in his marriage to wife, actress Tracy Pollan, in sickness and in health, and he stuck to his promise.

The couple, who met while auditioning for Family Ties in 1985, enjoyed marital bliss for three years before Fox's devastating Parkinson's disease in 1991 started to drive a wedge between them.

Instead of turning to his wife and loved ones for support, the actor, who was just 29 years old at the time, coped by drinking.

"I was isolating myself from my family," he said in an interview with People magazine.

It wasn't until one morning when Pollan found her husband passed out on the floor after a night of drinking that Fox knew he had to straighten up.

Pollan asked him, "Is this what you want? Is this what you want to be?" and walked out the door.

After that incident he went public with his illness and launched a foundation that has since raised nearly one billion dollars for Parkinson's research.

Over the years, Fox has made it clear that one of his main sources of strength is his wife. She has been by his side during some of the most trying times of his life and they have formed a very special bond.

The couple, who have four children together, son Sam, 29, twin daughters Schuyler and Aquinnah, 23, and daughter Esme, 16, spilled some of the secrets to their long marriage during the interview.

Not only did Fox's diagnosis bring them even closer, the pair revealed that they have always had similar values and upbringings.

"Big families, middle children," Fox told the magazine. "Sense of humor. Both our families had that."

Pollan added, "It was us against the world. That's exactly what we've created."

As for their trick to keeping their relationship strong after all these years? "Just give each other the benefit of the doubt," Pollan said. "He assumes I'm doing the best I can."

Fox chimed in, "Find the best things about you and the best things about life and celebrate them."

Pollan also gushed about her husband's "optimistic worldview" and admitted that he has added "so much" to her life.

While Fox doesn't worry much about the future, Pollan does, but it works well for them.

"It leaves a lot of work for other people sometimes because I'm like, 'Oh yeah, don't worry about it. It'll be great!' I can do that because I know she's got it handled," Fox said.

Fox and Pollan are a great example of how a Hollywood marriage can stand the test of time. Congratulations are in order for the couple who just celebrated their 30th wedding anniversary.