Demi Lovato has spoken for the first time since she was taken to hospital after suffering a suspected overdose.

The singer, 25, wrote a message to fans on her Instagram page saying she had learned addiction is "not something that disappears or fades with time" and "it is something I must continue to overcome and have not done yet".

Lovato also thanked staff at the Cedars-Sinai Medical Centre in Los Angeles, where she was taken after falling ill at her home in the Hollywood Hills on July 24.

She added: "I now need time to heal and focus on my sobriety and road to recovery. The love you have all shown me 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."

Lovato was a child star and found fame on the TV series Barney & Friends before appearing in the Disney Channel film Camp Rock.

She has since gone on to be a multi-platinum pop star with hits such as Sorry Not Sorry, Skyscraper and Heart Attack.

Lovato has been open about her struggles with alcohol and substance abuse and in June released a song, titled Sober, in which she indicated she had relapsed after six years of sobriety.

After reports emerged that New Mexico-born Lovato had been taken to hospital, the hashtag #PrayForDemi started trending on Twitter and celebrities including Ariana Grande, Cardi B and Nick Jonas tweeted messages of support.