In a YouTube video about her song "Father", the 23-year-old singer said, "I was very conflicted when he passed because he was abusive", reported Ace Showbiz.
Though her late father was abusive, Lovato admitted he had a kind heart.
"He was mean but he wanted to be a good person, and he wanted to have his family," the singer said.
"When my mom married my step-dad he still had this huge heart where he would say, 'I'm so glad Eddie's taking care of you and doing the job that I wish I could do.' "
"He knew he wasn't capable of raising a family, and it was because of his mental illness," she said.
The singer had been estranged from her father since 2007. Patrick passed away in 2013 after a battle with cancer.