Demi Lovato's mom Dianna De La Garza is giving her daughter's fans some good news and some major hope regarding their favorite pop star -- she announced on Maria Menounous' Sirius XM radio show that Demi is 90 days sober and doing well!

It's a relief for her friends, family and fans who were devastated following Lovato's opioid overdose in July at her Hollywood Hills home. De La Garza told Menounous, "Yes, she has 90 days [of sobriety]," De La Garza revealed. “And I couldn’t be more thankful or more proud of her because addiction being a disease, it’s work. It’s not easy. There are no short cuts." regarding Lovato's subsequent work in rehab.

When asked if she could see this coming, De La Garza answered: "I knew that she wasn’t sober, but let me clarify. I didn’t know what she was doing….because she doesn’t live with me. She’s 26. I just knew that she wasn’t sober. And that’s all I really knew at that time."

Menounous asked how Dianna learned of her daughter's overdose and it's a sad story ... "I was looking at my phone and I saw all these text messages coming in from all over… and the one text message that clued me in on what was going on said, ‘I just saw on TMZ and I’m so sorry.’ I was terrified to look at my phone." She said she was afraid her daughter had died in a car accident.

Demi has been open about her struggles with addiction, mental illness and an eating disorder. Lovato sought treatment for bipolar disorder, bulimia, self-harm and addiction in 2010. She relapsed after she left the treatment center, then entered a sober living facility for a year. She celebrated six years of sobriety in March, but admitting in her new single "Sober," released June 21, that she had relapsed. It was just a month later that her assistant found her unconscious in the singer's Hollywood Hills home from an apparent overdose and administered Naloxone to reverse the effects of the opioids Demi had taken. The antidote was successful and Demi was rushed to Cedars-Sinai Medical Center where she was treated for at least a week before being released and heading to rehab.