Ruby Rose has praised Demi Lovato's ''strength'' following her overdose.

The 25-year-old singer has recently been discharged from hospital after being admitted when she suffered an overdose at her Hollywood Hills home two weeks ago, and is set to enter rehab for her addictions.

Now, her close friend Ruby, 32, has praised her strength and courage following the incident, and says she's confident the 'Sorry Not Sorry' singer will leave rehab ''stronger'' than ever.

Speaking to People magazine, the 'Meg' actress said: ''She's a strong girl, and she's an amazing girl, and she's gonna definitely come back stronger, for sure.''

This isn't the first time Ruby has spoken in defence of Demi's strength, as she previously took to Twitter shortly after her pal was hospitalised to say she was sure Demi would be able to ''defeat'' her demons.

She wrote: ''My whole heart and my whole soul is with @ddlovato today. I adore you and so does the entire world. You will fight this and you will come out of it even stronger. Addiction is powerful beyond measure, but you can defeat it. I love you. (sic).''

Following her release from hospital, Demi broke her silence over the incident and thanked fans for their support as she vowed to do whatever she could to get back on the ''road to recovery.''

She wrote in an open letter posted on Instagram: ''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. I want to thank God for keeping me alive and well. To my fans, I am forever grateful for all of your love and support throughout this past week and beyond. Your positive thoughts and prayers have helped me navigate through this difficult time.

''I now need time to heal and focus on my sobriety and road to recovery. The love you have all shown will never be forgotten and I look forward to the day where I can say I came out on the other side. I will keep fighting.''

Demi - who has battled with drugs and alcohol abuse in the past - had stayed away from substances for six years but she recently revealed that she had fallen off the wagon when she released her song 'Sober' in June.