By Jessica Goodman
Updated October 06, 2015 at 04:15 PM EDT

Demi Lovato has been vocal about fighting the stigma against mental illness since being diagnosed with bipolar disorder when she was 19 years old. Tuesday, she’ll lobby for mental health care reform in Washington.

The conversation follows a national debate about mental health care, which was thrown back into the national spotlight after last week’s shooting at Umpqua Community College in Oregon.

Lovato, who is a spokesperson for Be Vocal: Speak up for Mental Health, spoke to MSNBC about the discussions surrounding mental health that take place after tragedies like school shootings. “Well, unfortunately, we’ve had several instances where mental health has been brought to the attention by the media because of these tragedies,” she said on MSNBC Live with Tamron Hall. “I think it’s really important to remember that people with mental illness are actually more likely to inflict harm on themselves and become the victim rather than be the perpetrators.”

Lovato also spoke about her experience and said, “I was lonely, I was sad, I was miserable, and I couldn’t figure out why, because I was on top of the world it felt like, but yes, I was struggling with it. And I want to do whatever I can to help others.”

The star, whose album Confident debuts Oct. 16, spoke to PEOPLE about visiting Capitol Hill and said, “The problem with mental illness is people don’t look at it as a physical illness. When you think about it, the brain is actually the most complex organ in your body. We need to treat it like a physical illness and take it seriously.”