Demi Lovato is celebrating staying sober for 90 days, according to her mum.

Dianna De La Garza told Maria Menounos’ Sirius XM show her daughter has not consumer alcohol or drugs since she was rushed to hospital following a drug overdose at her Hollywood Hills home in July.

“She has 90 days and I couldn’t be more thankful or more proud of her because addiction being a disease is work. It’s very hard and there are no short cuts.”

As for what caused the Sober singer to relapse, she said:

“I can’t really say for sure. I really don’t know.”

Lovato was found unresponsive in her Hollywood Hills home by her assistant, having overdosed on an unconfirmed substance. She spent about a week in hospital recovering, before heading straight to a rehab facility.

In her only statement to fans since the ordeal, Lovato said:

“I have always been transparent about my journey with addiction.

“What I’ve learned is that this illness is not something that disappears or fades with time. It is something I must continue to overcome and have not done yet.”