(Photo Credit: Andrew Burton/Getty Images)

In a surprise Christmas Eve video, the daughter of New York City Mayor-Elect Bill de Blasio revealed her long struggle with depression and drug abuse.

Chiara de Blasio, 19, was a prominent presence in her father's campaign. Her brother, Dante, 16, was the subject of one of the most talked about political ads this year.

In the video, Chiara reveals her struggle with clinical depression, which she said she has dealt with for most of her adolescence. And she discusses her struggle with alcohol dependence and marijuana use.

"I kind of kept just like reasoning and using this really fake rationale that was so justified to me that I could keep doing this stuff: 'Oh, I won't drink,' then I would just smoke weed. Then I would be like, 'Oh, I'm not going to smoke weed,' then I would just drink," the student at Santa Clara University in California says.

The revelation that she is a recovering alcoholic and drug abuser comes after her father was elected the first Democratic Mayor of New York City in 20 years after a campaign in which his family often emerged as a public subject.

In September, de Blasio opened up about his late father, a World War II veteran who struggled with alcoholism and subsequently killed himself after being diagnosed with late-stage cancer.

Chiara's video, sent out by the de Blasio transition team, is viewed as a proactive effort to release his daughter's story to the world on their own terms.

"Removing substances from my life, it opened so many doors for me," Chiara adds. "I was actually able to participate in my dad's campaign and that was actually the greatest thing ever. It's the hardest thing I've ever done. But it's so worth it."

Watch the full video: