MARIE OSMOND opened up to MARK STEINES about her 16-year-old son MICHAEL's current rehab stay.

"My son is the most amazing young man you will ever meet," Marie said of one of her eight children. "He's 16 and I could not be more proud of him than any mother on the planet."

Of his recent struggles, she said, "He's dealing with his issues, he's facing it."

"There are a lot of people who struggle with this nowadays," Marie told us. "Nobody is exempt, every family is touched by it."

For more with Marie, watch tonight's ET.